**2. Materials and methods**

118 Sexual Dysfunctions – Special Issue

the role of cGMP in the production and drainage of aqueous humor these medications do not appear to alter intraocular pressure and are safe in patients with glaucoma. All PDE5 inhibitors weakly inhibit PDE6 located in rod and cone photoreceptors resulting in mild and transient visual symptoms that correlate with plasma concentrations. Psychophysical tests reveal no effect on visual acuity, visual fields or contrast sensitivity; however, some studies show a mild and reversible impairment of blue-green colour discrimination. PDE5 inhibitors transiently alter retinal function on electroretinogram testing but do not appear to be retinotoxic. Despite the role of cyclic nucleotides in tear production there is no detrimental effect on tear film quality. Based on the available evidence PDE5 inhibitors have a good

It has been reported that sildenafil citrate significantly improves nocturnal penile erections in sildenafil non-responding patients with psychogenic erectile dysfunction (Abdel-Naser et al., 2004). Several pharmacological and physiological properties of sildenafil have been

In Nigeria, most individuals often use sildenafil citrate indiscriminately for sexual arousal. There is a growing apprehension that it could be harmful or injurious to the body. Though sildenafil is currently being used to treat erectile dysfunction in patients with multiple sclerosis, Parkinson disease, multisystem atrophy, and spinal cord injury by improving their neurologically related erectile dysfunction, conversely, it has been implicated in a number of neurological problems, such as intracerebral hemorrhage, migraine, seizure, transient global amnesia, nonarteritic anterior ischemic optic neuropathy, macular degeneration, branch retinal artery occlusion, and ocular muscle palsies. Thus, preclinical and very limited clinical data suggest that sildenafil may have therapeutic potential in selected neurological disorders. However, numerous reports are available regarding neurological adverse events ascribed to the drug. Although sildenafil shows some promise as a therapeutic agent in selected neurological disorders, well-designed clinical trials are needed before the agent can

The liver is the largest glandular organ of the body, weighing between 1.4-1.6kg. It lies below the diaphragm in the thoracic region of the abdomen. It plays a major role in metabolism and has a number of functions in the body, including glycogen storage, plasma protein synthesis, production of bile; an alkaline compound which aids in digestion, and

The Kidney is a paired organ located in the posterior abdominal wall, whose functions include the removal of waste products from the blood and regulation of the amount of fluid and electrolytes balance in the body. As in humans, the majority of drugs administered are eliminated by a combination of hepatic metabolism and renal excretion (Katzung 1998). The kidney also plays a major role in drug metabolism, but its major importance to drugs is still

Since the liver and kidneys are involved in the performance of these varied functions they may be susceptible to injury particularly in situation of toxicity. This work is carried out to investigate the histological effects of Sildenafil citrate on the liver and kidneys of adult Wistar rat. Though there are little or no literature report of toxicity of this drug on these two organs, but because they are vital organs in the body it is worthwhile to study its effects on

This study will further corroborate or disprove the toxic effects of Sildenafil citrate in organs other than sex organs, with a view to advising the consumers on the inherent dangers of

them. Though Daghfous et al., in 2005 reported that sildenafil-induced liver disease.

described (Cheitlin et al., 1999; Aviv et al., 2004; Galie et al., 2005; Hoeper et al., 2006)

be recommended for use in any neurological disorder (Farooq et al., 2008).

detoxification of most substances (Gartner and Hiatt, 2000).

its excretory functions.

excessive consumption of the aphrodisiac.

ocular safety profile (Kerr and Danesh-Meyer, 2009).

Twenty-four (24) adult Wistar rats of both sexes, weighing between 220.5g and 233.8g, with an average weight of 222.3g were randomly assigned into three treatment (n=18) and control (n=6) groups. The rats were obtained and maintained in the Animal holdings of the Department of Anatomy, School of Basic Medical Sciences, University of Benin, Benin city, Nigeria. They were fed with growers' mash obtained from Edo feed and flour mill limited, Ewu, Edo State and given water and feed ad libitum. The rats were acclimatized for 4 weeks before the experiment started.
