**3. Sexual function of 3,5-4-month-old males offsprings subjected to prenatal exposure of selective M- and N-cholinoblockers**

For the purpose of revealing sexual function abnormalities of puberal offsprings of male rats their primary sexual activity and dynamics of acquisition of sexual experience has been investigated. Offsprings of intact rats were control group.

The results obtained from behavioral studies showed that administration of methylbenactyzine and ganglerone to pregnant females at different periods of gestation induced long-term impairments to sexual function in pubescent offspring. In the first test, there were significant reductions in sexual function on appearance of primary sexual activity in offspring subjected to prenatal exposure to ganglerone (groups G10–G18) (Fig. 1). The males of this group included the large proportion of individuals in which all elements of sexual behavior were absent (henceforth – "inactive" individuals). The proportion of inactive males among the offspring of groups M10–M18 was significantly smaller and, after acquisition of sexual experience, decreased to 1–2 individuals in terms of both copulative (Fig. 1, B) and ejaculatory (Fig. 1, A) functions.

As not all males demonstrated sexual activity including the final component of sexual behavior, i.e., ejaculation, a group of males showing incomplete copulatory activity (mounting and intromission, without ejaculation) was identified (Fig. 1, B).

Analysis of the elements of sexual behavior over time (from test 1 to test 4) showed that the most marked differences in the intensity of acquiring sexual experience between offspring in groups G10–G18 and M10–M18 were seen in relation to the final element of copulation, i.e., ejaculatory activity. Offspring of groups G10–G18 showed positive dynamics only for copulatory activity, while there were no changes in the amounts of ejaculatory activity with the increase in sexual experience. The proportions of inactive males in terms of this parameters in groups G10–G18 amounted to about half of the total number of animals (from four to seven individuals) used for testing sexual behavior (Fig. 1).

Changes in the time parameters of sexual functions during four sessions of sexual behavior showed a similar dynamic for copulatory components. As sexual experience was acquired, the latent periods of the main elements of sexual behavior decreased, to a greater extent in males of groups M10–M18 than in offspring of groups G10–G18, and were comparable with control values (for example, mounting latencies are shown in Fig. 2).

Thus, more males which were inactive in the sexual behavior test (both before and after acquisition of sexual experience) were seen among the offspring of groups G10–G18 (particularly in males of group G10). A characteristic feature of the sexual behavior of males in these groups was the absence of marked dynamics of the acquisition of sexual experience by the fourth test.

Studies of the structure of sexual behavior in males with acquired sexual experience showed that sexual function in males of groups G10–G18 was characterized by very low values for the copulatory components of sexual behavior, with long latent periods. Levels of ejaculatory activity were extremely low (0.40 ± 0.16 ejaculations among the G10 offspring compared with 1.90 ± 0.18 in the control group).

The long latency of mounting in males of group G10 and, to a lesser extent, group G13, provides evidence of a significant alteration in the motivational component of sexual behavior (Fig. 2). In males of groups M10–M18 with acquired sexual experience, differences in sexual activity as compared with control offspring were less marked, with the exception of group M10, in which there was a significantly lower value of the ejaculatory component, without any change in the latent period of mounting. Analysis of the effects of prenatal

**3. Sexual function of 3,5-4-month-old males offsprings subjected to prenatal** 

For the purpose of revealing sexual function abnormalities of puberal offsprings of male rats their primary sexual activity and dynamics of acquisition of sexual experience has been

The results obtained from behavioral studies showed that administration of methylbenactyzine and ganglerone to pregnant females at different periods of gestation induced long-term impairments to sexual function in pubescent offspring. In the first test, there were significant reductions in sexual function on appearance of primary sexual activity in offspring subjected to prenatal exposure to ganglerone (groups G10–G18) (Fig. 1). The males of this group included the large proportion of individuals in which all elements of sexual behavior were absent (henceforth – "inactive" individuals). The proportion of inactive males among the offspring of groups M10–M18 was significantly smaller and, after acquisition of sexual experience, decreased to 1–2 individuals in terms of both copulative

As not all males demonstrated sexual activity including the final component of sexual behavior, i.e., ejaculation, a group of males showing incomplete copulatory activity

Analysis of the elements of sexual behavior over time (from test 1 to test 4) showed that the most marked differences in the intensity of acquiring sexual experience between offspring in groups G10–G18 and M10–M18 were seen in relation to the final element of copulation, i.e., ejaculatory activity. Offspring of groups G10–G18 showed positive dynamics only for copulatory activity, while there were no changes in the amounts of ejaculatory activity with the increase in sexual experience. The proportions of inactive males in terms of this parameters in groups G10–G18 amounted to about half of the total number of animals (from

Changes in the time parameters of sexual functions during four sessions of sexual behavior showed a similar dynamic for copulatory components. As sexual experience was acquired, the latent periods of the main elements of sexual behavior decreased, to a greater extent in males of groups M10–M18 than in offspring of groups G10–G18, and were comparable with

Thus, more males which were inactive in the sexual behavior test (both before and after acquisition of sexual experience) were seen among the offspring of groups G10–G18 (particularly in males of group G10). A characteristic feature of the sexual behavior of males in these groups was the absence of marked dynamics of the acquisition of sexual experience

Studies of the structure of sexual behavior in males with acquired sexual experience showed that sexual function in males of groups G10–G18 was characterized by very low values for the copulatory components of sexual behavior, with long latent periods. Levels of ejaculatory activity were extremely low (0.40 ± 0.16 ejaculations among the G10 offspring

The long latency of mounting in males of group G10 and, to a lesser extent, group G13, provides evidence of a significant alteration in the motivational component of sexual behavior (Fig. 2). In males of groups M10–M18 with acquired sexual experience, differences in sexual activity as compared with control offspring were less marked, with the exception of group M10, in which there was a significantly lower value of the ejaculatory component, without any change in the latent period of mounting. Analysis of the effects of prenatal

(mounting and intromission, without ejaculation) was identified (Fig. 1, B).

four to seven individuals) used for testing sexual behavior (Fig. 1).

control values (for example, mounting latencies are shown in Fig. 2).

**exposure of selective M- and N-cholinoblockers** 

investigated. Offsprings of intact rats were control group.

(Fig. 1, B) and ejaculatory (Fig. 1, A) functions.

compared with 1.90 ± 0.18 in the control group).

by the fourth test.

administration of substances at different periods of pregnancy showed that sexual function in the offspring was most sensitive to injection of the N-cholinolytic ganglerone at 9–11 and 12–14 days of gestation and the M-cholinolytic methylbenactyzine at 9–11 days of gestation. The comparative analysis of the other parametres of males sexual behaviour from the groups G10-G18 and M10-M18 with the acquired sexual experience showed more appreciable sexual dysfunctions of offsprings G10-G18 in comparison with the offsprings, that were subjected to prenatal influence of methylbenactyzine (tab. 1). The structure of sexual function of males from group G10-G18 with the acquired sexual experience was characterized by very low value of copulatory components and their high latence. Level of ejaculatory activity of all groups G10-G18 was extremely low and authentically differed from control group.

Fig. 1. Dynamics of the acquisition of sexual activity in offspring; data based on ejaculatory and copulatory (mountings and intromissions) behavior in four sequential tests for sexual behavior (data from tests 1 and 4) (n = 14). Dark columns show numbers of inactive males in the first test; shaded columns show inactive males in the fourth test. **A)** Number of inactive males in terms of ejaculatory activity (EA) in offspring subjected to prenatal exposure to ganglerone at 9–11, 12–14, and 17–19 days of pregnancy (groups G10, G13, and G18, respectively) or methylbenactyzine (groups M10, M13, and M18, respectively) compared with control offspring; **B)** number of inactive males in terms of incomplete copulatory activity (CA) (mountings and intromissions) in offspring of these groups.

Development of Male Sexual Function After Prenatal Modulation of Cholinergic System 99

prenatal alterations to the N-cholinergic and, to a lesser extent, the M-cholinergic system

induce long-term sexual impairments in the pubescent offspring.

**Intromissions** 

**(n)** 

**latency of** 

**intromission** 

**Control\_1** 9,70 ±1,93 123,2±42,8 6,10±1,08 166,2±42,6 1,20±0,20 369,8±65,0 504,0±49,5 328,0±26,7

**Control\_4** 15,8±2,15 23,6±28,3 9,50±1,65 73,8±35,8 1,90±0,18 297,4±48,9 362,6±39,5 270,3±15,6

**G-10\_1** 6,8±2,70 255,6±149,3 3,90±1,80 320,8±139,3 0,30±0,15 449,0±44,2 - 288±39,7

**G-10\_4** 9,80±3,22\* 89,1±33,6\* 6,10±2,09\* 50,7±25,5 0,50±0,27\* 312,7±49,8 457,5±56,5 325,3±29,0

**G-13\_1** 17,6±3,11 188,8±60,4 9,40±1,36 237,9±54,7 0,70±0,21 521,3±85,6 509,0±0,00 282,5±11,8

**G-13\_4** 17,1±3,1 26,0±9,0 11,4±2,1 53,9±16,0 0,90±0,17\* 278,8±53,0 403,5±29,1 307,7±23,2

**G-18\_1** 12,5±2,54 117,5±34,1 5,20±1,17 201,5±43,7 0,60±0,22 288,4±30,4 562,0±34,5 327,2±17,8

**G-18\_4** 28,9±3,76\* 16,9±3,30\* 15,2±2,19\* 69,1±15,3 1,07±0,16\* 525,8±22,2\* - 348,8±26,9

**M-10\_1** 18,3±3,57 27,8±3,44 11,0±2,0 58,5±10,2 0,89±0,26 512,7±88,1 509,5±49,5 328,2±44,4

**M-13\_1** 13,6±3,54 64,7±17,5 7,50±1,95 91,3±16,9 1,13±0,30 310,5±44,4 461,0±55,2 336,3±38,4

**M-18\_1** 6,70±1,84 123,0±26,6 4,00±1,23 165,2±33,2 1,00±0,30 223,3±29,5 428,0±45,8 318,7±33,6

**M-18\_4** 13,9±4,2 18,4±3,62 6,8±1,83\* 53,8±5,48 1,8±0,25 252,4±56,5 436,5±30,2 278,2±19,6

We believe that sexual dysfunction in adult offspring induced by prenatal exposure to cholinolytics is due to changes to neuronal and endocrine mechanisms. The mechanisms regulating sexual behavior are known to be mediated to a significant extent by neuronal structures located in the preoptic zone of the hypothalamus and to be activated by different neurotransmitter systems, including the cholinergic system (Dorner, 1989). Cholinergic activation of the preoptic area via M1 muscarinic receptors is critical for normal coitus (Hull et al., 1988a; Hull et al., 1988b; Retana et al., 1993). The absence of long-term sexual

**M-10\_4** 17,8±3,90 13,4±4,97\* 10,0±2,31 46,1±9,72 1,13±0,23\* 571,6±88,4\* 479,5±36,5\*

**M-13\_4** 12,3±2,16 19,3±3,98 5,000,96\* 69,7±5,66 1,50±0,27\* 227,7±36,4 453,8±21,4\*

Table 1. Parameters of sexual behavior in the mature male rats subjected to prenatal exposure to ganglerone (G) or methylbenactyzine (M) at different periods of prenatal

**(sec)** 

**Ejaculation** 

**(n)** 

**latency of** 

**ejaculation** 

**(sec)** 

**Interejaculatory** 

**interval** 

**(sec)** 

**Restoration** 

**period** 

296,3±36,2

345,6±20,8

**(sec)** 

Groups

**Mounts** 

**(n)** 

**\***-p < 0.05 compared with the control group. Abbr : **n**- number; **sec**- second of time.

development compared with the control group. (M±m).

**latency of** 

**mount** 

**(sec)** 

Fig. 2. Parameters of sexual behavior in the offspring of rats subjected to prenatal exposure to methylbenactyzine (M) or ganglerone (G) in the first and fourth tests. A) Latent period of mating. The ordinate shows time, sec; B) number of ejaculations throughout the sexual behavior test period. \*p < 0.05 compared with the control group. For further details see caption to Fig. 1.

Thus, the results of the present study show that treatment of pregnant females with ganglerone (and, to a lesser extent, methylbenactyzine) at different periods of pregnancy leads to behavioral abnormalities in the offspring: there were significant reductions in sexual function and the intensity of the acquisition of sexual experience.

The studies of Gladkova (1994) showed that the intensity of sexual behavior in males depends on having the appropriate experience. As a rule, sexual activity in the first test with receptive females was low, but increased from test to test such that the quantitative levels of sexuality in male rats were essentially constant after the third contact with females. Administration of the N-cholinolytic to pregnant females at 9–11 and 12–14 days of gestation facilitated the appearance of significantly larger proportions of inactive males among their offspring, these animals being characterized by an extremely low dynamic of the acquisition of sexual experience as compared with control offspring. In these males (groups G10–G13), acquisition of sexual experience was followed by sexual functions with significant disruption of ejaculatory activity and the central motivational element of sexual behavior. These data indicate that ganglerone modulation of the N-cholinergic system in the developing fetal brain leads to changes in the quantitative and qualitative characteristics of elements of sexual behavior in pubescent offspring.

In groups with prenatal exposure to the M-cholinolytic, changes in sexual function were noted only in offspring of group M10 – which had a significantly reduced level of the ejaculatory component as compared with control offspring, though this was not linked with changes in the motivational aspect of sexual behavior. These data showed that prenatal changes in the activity of the M-cholinergic system lead to insignificant behavioral consequences in pubescent offspring. Thus, the results obtained here provide evidence that


prenatal alterations to the N-cholinergic and, to a lesser extent, the M-cholinergic system induce long-term sexual impairments in the pubescent offspring.

**\***-p < 0.05 compared with the control group.

Abbr : **n**- number; **sec**- second of time.

98 Sexual Dysfunctions – Special Issue

Fig. 2. Parameters of sexual behavior in the offspring of rats subjected to prenatal exposure to methylbenactyzine (M) or ganglerone (G) in the first and fourth tests. A) Latent period of mating. The ordinate shows time, sec; B) number of ejaculations throughout the sexual behavior test period. \*p < 0.05 compared with the control group. For further details see

Thus, the results of the present study show that treatment of pregnant females with ganglerone (and, to a lesser extent, methylbenactyzine) at different periods of pregnancy leads to behavioral abnormalities in the offspring: there were significant reductions in

The studies of Gladkova (1994) showed that the intensity of sexual behavior in males depends on having the appropriate experience. As a rule, sexual activity in the first test with receptive females was low, but increased from test to test such that the quantitative levels of sexuality in male rats were essentially constant after the third contact with females. Administration of the N-cholinolytic to pregnant females at 9–11 and 12–14 days of gestation facilitated the appearance of significantly larger proportions of inactive males among their offspring, these animals being characterized by an extremely low dynamic of the acquisition of sexual experience as compared with control offspring. In these males (groups G10–G13), acquisition of sexual experience was followed by sexual functions with significant disruption of ejaculatory activity and the central motivational element of sexual behavior. These data indicate that ganglerone modulation of the N-cholinergic system in the developing fetal brain leads to changes in the quantitative and qualitative characteristics of

In groups with prenatal exposure to the M-cholinolytic, changes in sexual function were noted only in offspring of group M10 – which had a significantly reduced level of the ejaculatory component as compared with control offspring, though this was not linked with changes in the motivational aspect of sexual behavior. These data showed that prenatal changes in the activity of the M-cholinergic system lead to insignificant behavioral consequences in pubescent offspring. Thus, the results obtained here provide evidence that

sexual function and the intensity of the acquisition of sexual experience.

elements of sexual behavior in pubescent offspring.

caption to Fig. 1.

Table 1. Parameters of sexual behavior in the mature male rats subjected to prenatal exposure to ganglerone (G) or methylbenactyzine (M) at different periods of prenatal development compared with the control group. (M±m).

We believe that sexual dysfunction in adult offspring induced by prenatal exposure to cholinolytics is due to changes to neuronal and endocrine mechanisms. The mechanisms regulating sexual behavior are known to be mediated to a significant extent by neuronal structures located in the preoptic zone of the hypothalamus and to be activated by different neurotransmitter systems, including the cholinergic system (Dorner, 1989). Cholinergic activation of the preoptic area via M1 muscarinic receptors is critical for normal coitus (Hull et al., 1988a; Hull et al., 1988b; Retana et al., 1993). The absence of long-term sexual

Development of Male Sexual Function After Prenatal Modulation of Cholinergic System 101

Females embryos in groups with prenatal ganglerone exposure on 9-11 days of prenatal development also had authentic decrease of DA concentration and its useful increase (on 18,4 %, р≤0,01) after drug introduction on 12-14 day of gestation. At the same time fameles had more sugnificant change of DOPAC content. It was also noticed that in contrast to males, females embryos change of DA level was accompanied by more appreciable decrease of DA turnover in all experimental groups. The most appreciable decrease of DA/DOPAC ratio was reveled during early period of gestation after ganglerone exposure and during

Alteration of 5-HT level in the embryonal brain was more considerable in comparison with DA. Thus in all investigated periods of gestation in comparison with control group authentically significant reduction of 5-HT content in the embryos brain by exposure of

It was noted that males embryos 5-HT concentration in the brain was sugnificantly decreased in all periods of prenatal methylbenactyzine exposure. In the G10-G18 groups significant decrease of 5-HT concentration in the embryos brain is noted at drug introduction on 9-11 and 17-19 days of prenatal development. Dynamics of 5-HIAA (5 hydroxyindoleacetic acid) content (metabolite of 5-HT) was similar to the mediator content,

The comparative analysis of the received data shows that in the prenatal period the serotoninergic transmitter system is more sensitive to exposure of cholinolytics than dopaminergic system. 5-HT concentration and its turnover decrease during the second half of gestation with influence of the methylbenactyzine , and the ganglerone. Whereas the brain dopaminergic system of genotypical males and females embryos is more sensitive to

Many researches show the sensitivity of neurotransmitter system of a developing brain to influence of various drugs and ecological toxicants, possessing cholinergic activity. For example, the neurochemical alterations caused by the prenatal exposition of nicotine, are well studied; it is noticed that prenatally introduced nicotine damages development of the central mechanisms noradrenergic, dopaminergic, serotoninergic and cholinergic system in the rats brain (Lichtensteiger et al., 1988; Ribary & Lichtensteiger, 1989; King et al., 1991; Lichtensteiger & Schlumpf, 1993; Muneoka et al., 1997). Moreover, there is data that various reactions to prenatal exposure of nicotine are bound to a genetical sex of embryos (Genedani

Thus, prenatal cholinergic drug exposure produced dramatic imbalance of the neurotransmitter contents and turnover in the rat fetus brain on the 20th day of pregnancy. The comparative analysis showed that the serotoninergic neurotransmitter system was more sensitive to influence of cholinolytics in prenatal period than dopaminergic system. Decreasing of 5-HT concentration and its turnover in all «critical periods» on the second half of pregnancy was marked under influence as methylbenactyzine, and ganglerone, the Mand N-cholinolytics respectively. Whereas the brain dopaminergic system of genotypical males and famales embryos was more sensitive to influence of N-cholinotropic drug ganglerone. Thus, prenatal influence of cholinotropic drugs on pregnant females resulted in sex-linked alterations of brain dopaminergic and serotoninergic systems at 20-day's old fetuses of rats. These alterations can be involved to ethiopathogenesis of behavioral dysfunctions of rats progenies in pubertal period and be connected with deviant behavior.

more late pregnancy after methylbenactyzine exposure.

thus noted significant decrease in M10 - M13 and G10 groups.

methylbenactyzine and ganglerone was noted.

influence N-cholinergic antagonist ganglerone.

et al., 1983; Levin et al., 1993; Shacka et al., 1997).

**4.2 Metabolism of serotonine** 

dysfunction in offspring subjected to prenatal exposure to methylbenactyzine provides evidence that impairments to sexual function in males are not mediated by the Mcholinergic system of the brain.

#### **4. Neurochemical subsequences of prenatal exposure of selective M- and Ncholinoblockers in the rat fetus brain on the 20th day of pregnancy**

Prenatal cholinergic drug exposure to pregnant females resulted in sex-linked alterations of the brain dopaminergic and serotoninergic systems. Whereas the brain dopaminergic system of genotypical males and famales embryos was more sensitive to influence of Ncholinotropic drug ganglerone.

Neurochemical data analysis of the neurotransmitter status of the rats embryos brain of a various genetical sex has shown that prenatal influence by cholinolytics of the central action - methylbenactyzine and ganglerone– in case of injection on 9-19 days of the gestation causes a disbalance in the content of neurotransmitters of DA, 5-HT and their metabolites in the embryos brain of experimental groups by 20 day of prenatal development in comparison with control.

#### **4.1 Metabolism of dopamine**

Males embryos have a weaker density of DA (fig. 3) after prenatal ganglerone exposure on 9-11 days of prenatal development (G10 group). Level of DOPAC (dihydroxy-phenyl acetic acid), DA metabolite, did not change (tab. 2) during the same period. In G10 group decrease of the DA content was accompanied by augmentation of its turnover. At ganglerone introduction on 12-14 days of gestation was noted a substantial growth of DA level (on 29,9 %, р <0,01) which was not accompanied by change of its turnover that testifies the augmentation of mediatory synthesis intensity.

\*-p < 0.05 compared with the control group. For further details see caption to Fig. 1.

Fig. 3. Content of dopamine and serotonine (ng/mg of wet tissue) in the Brains of 20-day rat embryos. Notations: - **♂, - ♀ -** signs of genotypical males and famales embryos.

Females embryos in groups with prenatal ganglerone exposure on 9-11 days of prenatal development also had authentic decrease of DA concentration and its useful increase (on 18,4 %, р≤0,01) after drug introduction on 12-14 day of gestation. At the same time fameles had more sugnificant change of DOPAC content. It was also noticed that in contrast to males, females embryos change of DA level was accompanied by more appreciable decrease of DA turnover in all experimental groups. The most appreciable decrease of DA/DOPAC ratio was reveled during early period of gestation after ganglerone exposure and during more late pregnancy after methylbenactyzine exposure.

#### **4.2 Metabolism of serotonine**

100 Sexual Dysfunctions – Special Issue

dysfunction in offspring subjected to prenatal exposure to methylbenactyzine provides evidence that impairments to sexual function in males are not mediated by the M-

**4. Neurochemical subsequences of prenatal exposure of selective M- and N-**

Prenatal cholinergic drug exposure to pregnant females resulted in sex-linked alterations of the brain dopaminergic and serotoninergic systems. Whereas the brain dopaminergic system of genotypical males and famales embryos was more sensitive to influence of N-

Neurochemical data analysis of the neurotransmitter status of the rats embryos brain of a various genetical sex has shown that prenatal influence by cholinolytics of the central action - methylbenactyzine and ganglerone– in case of injection on 9-19 days of the gestation causes a disbalance in the content of neurotransmitters of DA, 5-HT and their metabolites in the embryos brain of experimental groups by 20 day of prenatal development in comparison

Males embryos have a weaker density of DA (fig. 3) after prenatal ganglerone exposure on 9-11 days of prenatal development (G10 group). Level of DOPAC (dihydroxy-phenyl acetic acid), DA metabolite, did not change (tab. 2) during the same period. In G10 group decrease of the DA content was accompanied by augmentation of its turnover. At ganglerone introduction on 12-14 days of gestation was noted a substantial growth of DA level (on 29,9 %, р <0,01) which was not accompanied by change of its turnover that testifies the

**Control**

**0,06**

Fig. 3. Content of dopamine and serotonine (ng/mg of wet tissue) in the Brains of 20-day rat

**0,07**

**0,08**

**0,09**

**0,10**

**0,11**

**0,12**

**0,13**

**G-10 -**

**\***

**\***

**G-13 -**

**G-18 -**

**M-10 -**

**M-13 -**

**M-18 -**

**Control**

**DA -♂ DA -♀**

**G-10 -**

**\***

**\***

**G-13 -**

**G-18 -**

**M-10 -**

**\*- p<0,05**

**M-13 -**

**M-18 -**

**\*- p<0,05**

\*-p < 0.05 compared with the control group. For further details see caption to Fig. 1.

embryos. Notations: - **♂, - ♀ -** signs of genotypical males and famales embryos.

**cholinoblockers in the rat fetus brain on the 20th day of pregnancy** 

cholinergic system of the brain.

cholinotropic drug ganglerone.

**4.1 Metabolism of dopamine** 

**\* \***

**\***

augmentation of mediatory synthesis intensity.

**5-HT -♂ 5-HT -♀**

**\* \* \* \* \*\* \***

with control.

**Control G-10 - G-13 - G-18 - M-10 - M-13 - M-18 - Control G-10 - G-13 - G-18 - M-10 - M-13 - M-18 -**

**0,06**

**0,07**

**0,08**

**0,09**

**0,10**

**0,11**

**0,12**

Alteration of 5-HT level in the embryonal brain was more considerable in comparison with DA. Thus in all investigated periods of gestation in comparison with control group authentically significant reduction of 5-HT content in the embryos brain by exposure of methylbenactyzine and ganglerone was noted.

It was noted that males embryos 5-HT concentration in the brain was sugnificantly decreased in all periods of prenatal methylbenactyzine exposure. In the G10-G18 groups significant decrease of 5-HT concentration in the embryos brain is noted at drug introduction on 9-11 and 17-19 days of prenatal development. Dynamics of 5-HIAA (5 hydroxyindoleacetic acid) content (metabolite of 5-HT) was similar to the mediator content, thus noted significant decrease in M10 - M13 and G10 groups.

The comparative analysis of the received data shows that in the prenatal period the serotoninergic transmitter system is more sensitive to exposure of cholinolytics than dopaminergic system. 5-HT concentration and its turnover decrease during the second half of gestation with influence of the methylbenactyzine , and the ganglerone. Whereas the brain dopaminergic system of genotypical males and females embryos is more sensitive to influence N-cholinergic antagonist ganglerone.

Many researches show the sensitivity of neurotransmitter system of a developing brain to influence of various drugs and ecological toxicants, possessing cholinergic activity. For example, the neurochemical alterations caused by the prenatal exposition of nicotine, are well studied; it is noticed that prenatally introduced nicotine damages development of the central mechanisms noradrenergic, dopaminergic, serotoninergic and cholinergic system in the rats brain (Lichtensteiger et al., 1988; Ribary & Lichtensteiger, 1989; King et al., 1991; Lichtensteiger & Schlumpf, 1993; Muneoka et al., 1997). Moreover, there is data that various reactions to prenatal exposure of nicotine are bound to a genetical sex of embryos (Genedani et al., 1983; Levin et al., 1993; Shacka et al., 1997).

Thus, prenatal cholinergic drug exposure produced dramatic imbalance of the neurotransmitter contents and turnover in the rat fetus brain on the 20th day of pregnancy. The comparative analysis showed that the serotoninergic neurotransmitter system was more sensitive to influence of cholinolytics in prenatal period than dopaminergic system. Decreasing of 5-HT concentration and its turnover in all «critical periods» on the second half of pregnancy was marked under influence as methylbenactyzine, and ganglerone, the Mand N-cholinolytics respectively. Whereas the brain dopaminergic system of genotypical males and famales embryos was more sensitive to influence of N-cholinotropic drug ganglerone. Thus, prenatal influence of cholinotropic drugs on pregnant females resulted in sex-linked alterations of brain dopaminergic and serotoninergic systems at 20-day's old fetuses of rats. These alterations can be involved to ethiopathogenesis of behavioral dysfunctions of rats progenies in pubertal period and be connected with deviant behavior.

Development of Male Sexual Function After Prenatal Modulation of Cholinergic System 103

in group with ganglerone exposure on 9-11 days of a gestation (fig. 4). Though in groups with prenatal exposure of a methylbenactyzine DA content in a hippocampus has not changed. In group M10 among offsprings with a prenatal exposition of a methylbenactyzine

Dynamics of DOPAC in the studied groups in comparison to control groups was opposite to DA content - substantial growth of DOPAC concentration in groups G10 and G13 (accordingly on 21,7 % and 26,3 %, р≤0,001) was noted. The neurochemical status in hippocampus of the males prenatally exposured to cholinolytics was characterized by serious decrease of DA

concentration and change of its metabolite level in comparison with control offsprings.

**Control**

wet tissue) in the hippocampus in two-month-old rat offspring exposed to

compared with the control group. For further details see caption to Fig. 1.

**0,00**

**0,01**

**0,02**

**0,03**

**0,04**

**0,05**

**G-10**

\*\*

**G-18**

**NA**

**G-13**

Fig. 4. Contents of dopamine (DA), noradrenaline (NA), and serotonine (5-HT) (ng/mg of

methylbenactyzine or ganglerone at different periods of prenatal development. \*p < 0.05

The obtained data showed decrease of the NA content and increase of its metabolite MHPG (3-methoxy-4-hydroxyphenylethylene glycol) concentration that led to NA synaptic activity decrease. In case of rats males decrease of NA concentration in hippocampus was noted only in two groups subjected to prenatal exposure of a ganglerone in early periods of gestation - G10 and G13 (accordingly 66,6 % and 70,0 %, р≤0,001). Thus the content of a noradrenaline metabolite of MHPG has been enlarged in all investigated groups in 1,5 - 2,0

Unlike other neurotransmitters 5-HT level in the hippocampus has been reduced in all groups of both gender in comparison with control offsprings group. Males offsprings had significant reduction of 5-HT content in the range from 19,7 % (р≤0,01) - in G10 and to 32,6 % (р≤0,001) in M18 group. The serotonin metabolite level 5-HIAA in the hippocampus also

**М-10**

**М-18**

**Control**

**0,0**

**0,1**

**0,2**

**0,3**

**0,4**

**0,5**

**0,6**

**G-10**

**G-13**

**G-18**

\*

\*

\* -p<0,05

\* \*

**5-HТ**

**М-10**

**М-18**

\*

was noted a tendency to augmentation.

**G-10 G-13 G-18**

**5.1.1 NA metabolism** 

**5.1.2 5-HT metabolism** 

\*

**Control**

**0,0**

times*.* 

**1,0**

**2,0**

**3,0**

**4,0**

**5,0**

**М-10**

**DA**

\* \*

**М-18**


\*-p < 0.05 compared with control group.

Table 2. Content of DOPAC and 5-HIAA in the brains of 20-day rat embryos. (M ± m) Notations: - **♂, - ♀ -** simbols of the genetical sex of offspring, accordingly males and females.
