**6. References**

128 Basic and Clinical Endocrinology Up-to-Date

OAT gene in the male mouse kidney. Furthermore, orchidectomy completely abolished the sexual dimorphism of the renal expression of OAT gene (Levillain et al., 2007). The present findings confirm these statements. Moreover, our results show that testosterone negatively regulated the expression of OAT gene at the transcriptional level. Indeed, the levels of OAT mRNA, protein, and enzyme activity were markedly increased following castration. The castrated male mice were killed either 11 days or 18 days after the surgery to completely deplete the endogenous pool of testosterone. Plasma testosterone levels showed that all mice

To further explore the mechanismes involved in the regulation of OAT gene by testosterone in the mouse kidney, experiments were conducted to test the consequence of testosterone replacement on the expression of OAT gene at the transcriptional, translational, and posttranslational levels. The dose of testosterone injected was calculated to reach a physiological plasma level of testosterone. The efficiency of testosterone to lower the level of OAT mRNA in the mouse kidney was confirmed. These results demonstrate that testosterone regulates OAT gene expression at the transcriptional level. The regulation of OAT gene at the transcriptional level has been also reported in the rat tissues (Mueckler & Pitot, 1983; Mueckler et al., 1983, 1984). The levels of OAT protein and OAT activity were also diminished by a single injection of testosterone, however, this decrease was less pronounced than that of OAT mRNA. This difference may be explained by the long half-life of OAT protein. The half-life of OAT protein is estimated at about 48 hrs (Ip et al., 1974). The timecourse study of the effect of testosterone on the expression of OAT gene in castrated male mice also supports this timeline with the level of OAT mRNA decreasing more rapidly than OAT activity. This experiment also revealed a lag-time of 8 hrs or more from testosterone administration before detecting significant changes in the level of OAT mRNA. Similar results were observed with injection of testosterone to female mice (paper in preparation). This delay from administration to mRNA expression suggests that several genomic and/or non-genomic events may take place in the signaling cascade of testosterone (Heinlein & Chang, 2002). One hypothesis is that a target molecule such as the eukaryotic initiation factor eIF4-E is rate-limiting for OAT translation (Fagan et al., 1991). However, in our expriments, the level of eIF4-E mRNA was altered neither by orchidectomy nor by

In order to explain a direct genomic action of testosterone, an attempt was made to identify ARE on the promoter of the mouse OAT gene. We carried out an *in silico* search for homology to the consensus ARE motifs by selecting either the left half-site 5'-AGAACA-3' or the right half-site 5'-TGTTCT-3' motifs by search computational using MatInspector (http://www.genomatix.de/) (Beato et al., 1989; Fabre et al., 1994; Roche et al., 1992; Wang et al., 2007; Merkulov & Merkulova, 2009). Several ARE (5'-AGAACAnnnTGTTCT-3') and glucocorticoid responsive element (GRE, 5'-GGTACAnnnTGTTCT-3') which share the same sequence 5'-TGTTCT-3' (Nelson et al., 1999, Verrijdt et al., 2003) were identified on the promoter of the mouse OAT gene. Interestingly, four GRE have been found in the human OAT gene (Zintz & Inana, 1990). Further experiments will be required to determine the

Recently, it has been reported that, in Swiss CD1 mice, sex hormones influence the weight of the adrenal gland and the plasma level of corticosterone (Bastida et al, 2007). Indeed, the weight of the female adrenal gland was 2.8-fold higher than that of the male (Bastida et al, 2007). Orchidectomy enhanced the weight of the male adrenal gland by 2.1-fold whereas

functionality of these elements in response to hormone administration.

were testosterone-free as soon as 11 days after castration (Levillain et al., 2005).

testosterone replacement.


Orchidectomy Upregulates While Testosterone Treatment Downregulates

Vol.4, No.10, pp e7309, ISSN 1932-6203.

Vol.146, No.2, pp 950-959, ISSN 0013-7227

1027, ISSN 0363-6127

No.2, pp 472-479, ISSN 0003-9861

Vol.27, No.3, pp 287-295, ISSN 1357-2725

*Biology,* Vol.115, No.1-2, pp 1-8, ISSN 1879-1220

Vol.258, No.3 , pp 1781-1784, ISSN 0021-9258

the Expression of Ornithine Aminotransferase Gene in the Mouse Kidney 131

Laemmli, UK. (1970). Cleavage of structural proteins during the assembly of the head of bacteriophage T4. *Nature,* Vol.227, No.5259, pp 680-685, ISSN 0028-0836 Lambert-Langlais, S.; Pointud, J.C.; Lefrancois-Martinez, A.M.; Volat, F.; Manin, M.;

Levillain, O.; Hus-Citharel, A.; Garvi, S.; Peyrol, S.; Reymond, I.; Mutin, M. & Morel, F.

*Physiology - Renal Physiology,* Vol.286, No.4, pp F727-F738, ISSN 0363-6127 Levillain, O.; Diaz, J-J.; Blanchard, O. & Dechaud, H. (2005). Testosterone down-regulates

Levillain, O.; Ventura, G.; Dechaud, H.; Hobeika, M.; Meseguer, A.; Moinard, C. & Cynober,

Lyons, R.T. & Pitot, H.C. (1977). Hormonal regulation of ornithine aminotransferase

Manteuffel-Cymborowska, M.; Chmurzynska, W.; Peska, M. & Grzelakowska-Sztabert, B.

Merkulov, V.M. & Merkulova, T.I. (2009). Structural variants of glucocorticoid receptor

Mueckler, M.M. & Pitot, H.C. (1983). Regulation of ornithine aminotransferase mRNA levels

Mueckler, M.M.; Moran, S. & Pitot, H.C. (1984). Transcriptional control of ornithine

*Journal of Biological Chemistry,* Vol.259, No.4, pp 2302-2305, ISSN 0021-9258 Natesan, S. & Reddy, S.R. (2001). Compensatory changes in enzymes of arginine metabolism

*Biochemistry & Molecular Biology,* Vol.130, No.4, pp 585-595, ISSN 1096-4959 Nelson, C.C.; Hendy, S.C.; Shukin, R.J.; Cheng, H.; Bruchovsky, N.; Koop, B.F. & Rennie, P.S.

Coudore, F.; Val, P.; Sahut-Barnola, I.; Ragazzon, B.; Louiset, E.; Delarue, C.; Lefebvre, H.; Urade, Y. & Martinez, A. (2009). Aldo keto reductase 1B7 and prostaglandin F2alpha are regulators of adrenal endocrine functions. *PLoS One,* 

(2004). Ornithine metabolism in male and female rat kidney: mitochondrial expression of ornithine aminotransferase and arginase II. *American Journal of* 

ornithine aminotransferase gene and up-regulates arginase II and ornithine decarboxylase genes for polyamines synthesis in the murine kidney. *Endocrinology,* 

L. (2007). Sex-differential expression of ornithine aminotransferase in the mouse kidney. *American Journal of Physiology - Renal Physiology,* Vol.292, No.3, pp F1016-

biosynthesis in rat liver and kidney. *Archives of Biochemistry and Biophysics,* Vol.180,

(1995). Arginine and ornithine metabolizing enzymes in testosterone-induced hypertrophic mouse kidney. *The International Journal of Biochemistry & Cell Biology,*

binding sites and different versions of positive glucocorticoid responsive elements: Analysis of GR-TRRD database. *The Journal of Steroid Biochemistry and Molecular* 

in rat kidney by estrogen and thyroid hormone. *The Journal of Biological Chemistry,* 

aminotransferase synthesis in rat kidney by estrogen and thyroid hormone. *The* 

during renal hypertrophy in mice. *Comparative Biochemistry and Physiology Part B,* 

(1999). Determinants of DNA sequence specificity of the androgen, progesterone, and glucocorticoid receptors: evidence for differential steroid receptor response elements. *Molecular Endocrinology,* Vol.13, No.12, pp 2090-2107, ISSN 0888-8809 Peraino, C. & Pitot, H.C. (1963). Ornithine-δ-transaminase in the rat. I. Assay and some

general properties. *Biochimica et Biophysica Acta,* Vol.73, pp 222-231, ISSN 0006-3002


Beato, M.; Chalepakis, G.; Schauer, M. & Slater, E.P. (1989). DNA regulatory elements for

Bitoun, M.; Levillain, O. & Tappaz, M. (2001). Gene expression of the taurine transporter and

Bradford, M.M. (1976). A rapid and sensitive method for the quantitation of microgram

Déchaud, H.; Lejeune, H.; Garoscio-Cholet, M.; Mallein, R. & Pugeat, M. (1989).

Fagan, R.J.; Karatzas, A.L.; Sonenberg, N. & Rozen, R. (1991). Translational control of

Herzfeld, A. & Knox, W.E. (1968). The properties, developmental formation, and estrogen

Herzfeld, A. & Greengard, O. (1969). Endocrine modification of the developmental

Ip, M.M.; Chee, P.Y. & Swick, R.W. (1974). Turnover of hepatic mitochondrial ornithine

Kasahara, M.; Matsuzawa, T.; Kokubo, M.; Gushiken, Y.; Tashiro, K.; Koide, T.; Watanabe,

*Biochimica et Biophysica Acta,* Vol.354, No.1, pp 29-38, ISSN 0006-3002 Jariwala, U.; Prescott, J.; Jia, L.; Barski, A.; Pregizer, S.; Cogan, J.P.; Arasheben, A.; Tilley,

*Chemistry,* Vol.243, No.12, pp. 3327-3332, ISSN 0021-9258

*Chemistry,* Vol.244, No. 18, pp. 4894-4898, ISSN 0021-9258

*Cancer,* Vol.6, No.6, pp 39, ISSN 1476-4598

*Biological Chemistry,* Vol.266, No.25, pp 16518-16523, ISSN 0021-9258 Filipski, E.; King, V.M.; Li, X.; Granda, T.G.; Mormont, M.C.; Liu, X.; Claustrat, B.; Hastings,

plasma. *Clinical chemistry,* Vol.35, No.8, pp. 1609-1614, ISSN 0009-9147. Fabre, S.; Manin, M.; Pailhoux, E.; Veyssiere, G. & Jean, C. (1994). Identification of a

*Biochemistry,* Vol.72, pp. 248-254, ISSN 0003-2697

0022-4731

6768

9258

0022-1554

pp 2181-2187, ISSN 0888-8809

steroid hormones. *Journal of Steroid Biochemistry,* Vol.32, No.5, pp 737-747, ISSN

taurine biosynthetic enzymes in rat kidney after antidiuresis and salt loading. *Pflügers Archiv - European Journal of Physiology,* Vol.442, No.1, pp. 87-95, ISSN 0031-

quantities of protein utilizing the principle of protein-dye binding. *Analytical* 

Radioimmunoassay of testosterone not bound to sex-steroid-binding protein in

functional androgen response element in the promoter of the gene for the androgen-regulated aldose reductase-like protein specific to the mouse vas deferens. *The Journal of Biological Chemistry,* Vol.269, No.8, pp 5857-5864, ISSN 0021-

ornithine aminotransferase. Modulation by initiation factor eIF-4E. *The Journal of* 

M.H. & Levi, F. (2002). Host circadian clock as a control point in tumor progression. *Journal of the National Cancer Institute*, Vol.94, No.9, pp. 690-697, ISSN 0027-8874 Heinlein, C.A. & Chang, C. (2002). The roles of androgen receptors and androgen-binding

proteins in nongenomic androgen actions. *Molecular Endocrinology* Vol.16, No.10,

induction of ornithine aminotransferase in rat tissues. *The Journal of Biological* 

formation of ornithine aminotransferase in rat tissues. *The Journal of Biological* 

aminotransferase and cytochrome oxidase using (14C)carbonate as tracer.

W.D.; Scher, H.I.; Gerald, W.L.; Buchanan, G.; Coetzee, G.A. & Frenkel, B. (2007). Identification of novel androgen receptor target genes in prostate cancer. *Molecular* 

H. & Katunuma, N. (1986). Immunohistochemical localisation of ornithine aminotransferase in normal rat tissues by Fab'horseradish peroxidase conjugates. *The Journal of Histochemistry and Cytochemistry,* Vol.34, No.11, pp 1385-1388, ISSN


**Part 4** 

**Insulinomas** 


**Part 4** 

**Insulinomas** 

132 Basic and Clinical Endocrinology Up-to-Date

Roche, P.J.; Hoare, S.A. & Parker, M.G. (1992). A consensus DNA-binding site for the

Sanada, Y.; Suemori, I. & Katunuma, N. (1970). Properties of ornithine aminotransferase

Ventura, G.; De Bandt, J.P.; Segaud, F.; Perret, C.; Robic, D.; Levillain, O.; Le Plenier, S.;

Verrijdt, G.; Haelens, A. & Claessens, F. (2003). Selective DNA recognition by the androgen

*Molecular Genetics and Metabolism,* Vol.78, No. 3, pp 175-185, ISSN 1096-7192 Wakabayashi, Y. (2004). The glutamate crossway. In: *Metabolic & Therapeutic Aspects of Amino* 

Wang, Q.; Li, W.; Liu, X.S.; Carroll, J.S.; Janne, O.A.; Keeton, E.K.; Chinnaiyan, A.M.; Pienta,

Yu, H.; Yoo, P.K.; Aguirre, C.C.; Tsoa, R.W.; Kern, R.M.; Grody, W.W.; Cederbaum, S.D. &

Zintz, C.B. & Inana, G. (1990). Analysis of the human ornithine aminotransferase gene family. *Experimental Eye Research,* Vol.50, No.6, pp 759-770, ISSN 0014-4835

8809

No.1, pp 42-50, ISSN 0006-3002

pp 380-392, ISSN 0021-9258

*Nutrition,* Vol.101, No.6, pp 843-851, ISSN 1475-2662

Press, ISBN 0-8493-1382-1, Boca Raton, USA

Vol.51, No.9, pp 1151-1160, ISSN 0022-1554

androgen receptor. *Molecular Endocrinology* Vol.6, No.12, pp 2229-2235, ISSN 0888-

from rat liver, kidney and small intestine. *Biochimica et Biophysica Acta,* Vol.220,

Godard, C.; Cynober, L. & Moinard, C. (2009). Overexpression of ornithine aminotransferase: consequences on amino acid homeostasis. *The British Journal of* 

receptor as a mechanism for hormone-specific regulation of gene expression.

*Acids in Clinical Nutrition*, L. Cynober, (Ed.), pp. 135-152, Taylor & Francis CRC

K.J. & Brown, M. (2007). A hierarchical network of transcription factors governs androgen receptor-dependent prostate cancer growth. *Molecular Cell,* Vol.27, No.3,

Iyer, R.K. (2003). Widespread expression of arginase I in mouse tissues. Biochemical and physiological implications. *The Journal of Histochemistry and Cytochemistry*

**8** 

*France* 

D. Vezzosi et al.\*

**Diagnosis and Treatment of** 

*Department of Endocrinology, CHU Larrey, Toulouse* 

Insulinomas are rare endocrine tumours developed from pancreatic beta cells. Their incidence is about 1 in 250,000 patient-years (Cryer 2008) (0.396 per 100,000 person-years for two decades, 1967-1986) (Service et al. 1991). The median age at surgical diagnosis was found to be 47 years (8 to 82), 59% being female patients. In a series of 33 patients, the age at the time of diagnosis was 57 +/- 16 years (mean +/- SD) (range: 18-85 years) and 66% were female patients (Vezzosi et al. 2007). 90% of insulinomas are single, benign and sporadic tumours that are located in the pancreas. The diagnostic and therapeutic strategy of benign sporadic insulinomas has been now established by a recent expert consensus (Cryer et al. 2009). However, some issues remain unaddressed regarding the diagnosis and the treatment of insulinomas. More rarely, in about 10% of insulinoma patients, the insulinoma is part of MEN-1. Such patients often present with multiple insulinomas and other secreting or non-secreting endocrine tumours. Finally, a particular condition is malignant insulinoma, also found in about 10% of insulinoma patients. There are no recommendations regarding the particular conditions represented by insulinomas in

The aim of this chapter is to give an updated and detailed view of the medical management of adult patients with insulinoma regarding the diagnosis (diagnosis of hypoglycemia related to endogenous hyperinsulinism, differential diagnosis, topographic assessment) and the treatment (surgery, medical therapies), including the therapeutic strategy and the possibilities of long-term medical treatment in inoperable patients. The first part of the chapter will be focused on the most frequent case, i.e. single benign sporadic insulinoma. The remaining parts of the chapter will deal with specific issues and concerns regarding malignant insulinomas, insulinomas in genetic disorders, and the rare cases of

D. Vezzosi1, A. Bennet1, J.C. Maiza1, A. Buffet1, S. Grunenwald1, J. Fauvel2, F. Courbon3, P. Otal4, N.

**1. Introduction** 

MEN-1 and malignant insulinomas.

nesidioblastosis in the adults.

*2Laboratory of Biochemistry, IFB, CHU Purpan, 3Department of Nuclear Medicine, CHU Rangueil, 4Department of Radiology, CHU Rangueil,* 

*5Department of Surgery, CHU Purpan, Toulouse, France*.

*1Department of Endocrinology and Metabolic Diseases, CHU Larrey,* 

Carrere5 and Ph. Caron1

 \*

**Insulinomas in the Adults** 
