Search

The present study was undertaken to explore the effects of monensin, a potent Golgi disturbing agent on male fertility.Male Wistar rats were administered monensin at the dose levels of 2.5, 5, and 10 mg/kg b wt. Animals were sacrificed after 67 days of the treatment. The activities of lactate dehydrogenase (LDH), ATPase, acid phosphatase and thiamine pyrophosphatase (TPPase) were measured in the testis. Cytochemical assay of Golgi body marker enzyme, thiamine pyrophosphatase was also performed. Ultrastructural changes in testis were studied by Transmission electron microscopy. Sperm number and motility were also examined.The alterations in the activities of above mentioned enzymes indicate the pronounced effect of the drug on the functioning of spermatogenic cells. The findings from electron microscopy such as membrane disruption, swelling and disintegration of Golgi apparatus strongly suggest the interference of monensin with the functioning of Golgi apparatus in the spermatogenic cells. Data from the sperm number and motility as well as the fertility studies and the resulted litter size further points towards the antifertility effects of monensin in male rats.The findings from the present study strongly indicated the effects of monensin on the testis, involving alterations in key enzyme activities and changes at the ultrastructural level.

The effect of monensin, a Na+-specific ionophore on the oxidative defense system in rat testis was studied. Monensin mixed in the animal diet was administered at the dose levels of 2.5, 5 and 10 mg/kg b.w. to Wistar rats for a period of 67 days. A marked inhibition in the activities of different oxidative defense enzymes such as catalase, glutathione peroxidase, glutathione-S-transferase, superoxide dismutase and glutathione reductase was noticed, which indicates the possible involvement of free radicals in the antispermatogenic effects of monensin in rat testis. This was further substantiated by a significant increase in the generation of lipid peroxides along with the depletion of reduced glutathione. The drug treatment resulted in a significant change in apoptotic cell death as seen by an elevated fragmentation in the testicular genomic DNA. Monensin treatment also resulted in marked degenerative changes in the histoarchitecture of testis, such as depletion of different germ cell populations, vacuole formation and disorganization of seminiferous tubules. The results are indicative of the potential antispermatogenic effects of monensin in the rat.

Monensin, a sodium specific ionophore was evaluated for its in vitro effects on rat testis by studying changes at biochemical parameters as well as at the DNA level. It was observed that monensin produced marked alterations in the activities of various enzymes associated with the testicular functions. The significant inhibition of different enzymes of oxidative defense system points toward the generation of reactive oxygen species (ROS) by monensin treatment. The significant depletion of reduced glutathione and elevation in the level of lipid peroxidation further support the above findings. The significant inhibition of the activities of lactate dehydrogenase and adenosine triphosphatase shows the interference of monensin with the normal energy supply in spermatogenesis. Moreover, the significant increase in the activities of acid phosphatase and thiamine pyrophosphatase demonstrates the interference of monensin with the Golgi-lysosomal complex of the rat testis. Induced DNA fragmentation indicates towards the impact of monensin on the DNA integrity and apoptosis. Further studies are needed to understand the important molecular mechanisms responsible for these effects.

To determine the (reversible) antifertility effect in the male rat of sulfasalazine, a common therapy for inflammatory bowel disease.Sulfasalazine (120, 250 and 500 mg/kg) was administered for 60 days by oral gavage to sexually mature male rats.Both motility of sperm and fertility of animals was significantly altered at the highest dose (500 mg/kg). Morphological abnormalities included alteration in the normal profile of the spermatozoa and presence of lesions on the sperm head.Results suggest that sulfasalazine brings about its antifertility effects by altering sperm motility and number of spermatozoa in addition to increased surface abnormalities, which render the spermatozoa infertile.

Male rats administered sulphapyridine (60, 120 and 250 mg/kg) for 60 days demonstrated no change in body weight and testicular weight. However, there was a decrease in the weight of the epididymis. Motility and sperm reserves were reduced and were evident from fewer implantation sites and number of pregnancies. Furthermore, sulphapyridine did not show any effect on the histoarchitecture of the testis or epididymis. Serum levels of testosterone in the treated rats were comparable to their respective controls. Morphological abnormalities as revealed by scanning electron microscopic studies clearly demonstrated the detrimental effects of the drug.

Male rabbits and rats were administered gossypol (20 mg/kg/day) for 12 and 7 weeks respectively. Gossypol was estimated in different organs by the aniline method of Smith. Rat and rabbit spleen accumulated the highest level of gossypol. The lowest amount of gossypol was accumulated in the rabbit brain; the level of gossypol in rat brain was below the detectable limit of our method. Although rabbits were administered gossypol for 12 weeks, the accumulation of gossypol in rabbit testis was much lower than that of the rat testis. Our data suggest that non-sensitivity of rabbit to the antifertility effect of gossypol may be due to poor accumulation of gossypol in the testis. Negligible amount of gossypol in the brain rules out the possibility of involvement of hypothalamus-pituitary axis in the mechanism of action of gossypol on the testis.

Male hamsters and rats were administered gossypol 10 mg/kg/day for 45 and 56 days respectively. Twenty four hours before the last dose, animals were administered 65Zn (specific activity 0.258 uci/mg) subcutaneously. A marked decrease in 65Zn incorporation was observed in testis, epididymis, seminal vesicles and prostate following drug administration. A significant increase in 65Zn uptake was however observed in vas deferens in both rat and hamster following drug administration. Our results suggest that whatever the mechanism of gossypol action on testis-epididymis complex may be, the marked decrease in 65Zn uptake by testis--epididymis complex following gossypol treatment may be related to the antispermatogenic effect of gossypol.

Sexually mature male albino rats were divided into four groups of 5 animals each. Animals of group I served as control, whereas animals of group II received gossypol (20 mg/kg body weight/day) for 45 days. Animals of groups III and IV were maintained on protein deficient diet. Animals of group IV received 20 mg/kg gossypol in addition to the protein deficient diet. Animals of group III and IV received protein deficient diet for 45 days before initiating gossypol treatment. The total period of maintaining the animals on protein deficient diet was 90 days. In another experiment, the same experimental protocol was followed except that the animals were maintained on low potassium diet instead of protein deficient diet. A significant decrease in body weight of animals was observed following protein deficient and gossypol (group IV) treatment. Testis weight decreased significantly in the animals of group III (protein deficient) and group IV (protein deficient + gossypol). Similar observations were made in the animals maintained on low potassium diet. In both the experiments, sperm motility was reduced significantly. Histologically, in the testis of animals of group IV (protein deficient + gossypol) almost all the tubules were disorganised and vacuolated and total arrest of spermatogenesis could be observed in majority of the tubules.

Eighty male rats were grouped into 8 groups of 10 animals each. Animals in groups I-IV were given gossypol (40 mg/kg/day) for 7, 14, 21 and 28 days respectively. Animals of groups V-VIII served as respective controls for groups I-IV. Marked changes in the activities of ATPase and SDH were observed following drug treatment. Decrease in the activity of testis LDH was evident even after 7 days of drug treatment. Activities of B-galactosidase, Glucose-6-phosphatase and Fructose-1-6-diphosphatase were not affected by gossypol treatment. Glycogen contents in testis were not different from those of the controls. A significant decrease in the tubular diameter and germinal height of the seminiferous tubules was observed after 21 days of drug treatment. Quantitative analysis of spermatogenic elements revealed marked decrease in the ratios of resting spermatocyte. A type spermatogonia, pachytene spermatocyte/resting spermatocyte, and stage 19 spermatids/stage 7 spermatids after 7 days of drug treatment. A progressive decrease in the ratios of these cell types was observed as the duration of the drug treatment was extended. Liver enzymes (except SDH and LDH after 28 days of drug treatment) were not affected by gossypol treatment. Our data strongly suggest that degenerative changes in the testis start after one week of drug administration. The histological changes visible at light microscopy level start appearing after 14 days of drug treatment.

Thirty male rats were grouped into 5 groups of 6 animals each. Animals in groups II-V were given gossypol at a dose of 5 mg/kg, 10 mg/kg, 20 mg/kg and 40 mg/kg body weight per day for 45 days respectively. Animals of group I served as control. A significant decrease in body weight after administration of 40 mg/kg body weight of gossypol was observed; low doses of gossypol, however did not affect the body weight. Testis, epididymis, prostate and seminal vesicles weights decreased gradually with the increasing doses of gossypol. With the increasing doses of gossypol, a marked decrease in the vas deferens sperm motility was observed. At 40 mg/kg dose there was a total inhibition of sperm motility. Histological studies after 5 mg/kg revealed no apparent sign of degeneration, while after 10 mg/kg dose the changes in the individual cell types were accompanied by overall disorganisation of the germinal epithelium involving displacement of the spermatocytes. The rats treated with 20-40 mg/kg gossypol showed a pronounced deleterious effect on the histological structure of the testis. The drug effect was dose dependent developing sequentially; from the uppermost layer of elongated spermatids affecting round spermatids and finally spermatocytes. Quantitatively the ratios of pachytene spermatocytes: resting spermatocytes, stage 7 spermatids: pachytene spermatocytes, and stage 19 spermatids: stage 7 spermatids and tubular diameter and germinal height decreased significantly. The activities of glucose-6-phosphatase, fructose 1, 6-diphosphatase, glucose-6-phosphate isomerase in testis decreased significantly at high dose (40 mg/kg), while the activity of amylase and glycogen content increased significantly with the increasing doses of gossypol.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration of vasodilator, sodium nitrite (20 mg/kg body weight), 30 min before alpha-chlorohydrin treatment (90 mg/kg body weight) prevented the chlorohydrin-induced lesion in rat testis--epididymis complex. However, administration of vasodilator 90 min after alpha-chlorohydrin treatment did not prevent the chlorohydrin-induced lesion in the testis--epididymis complex. These observations suggest that the testicular vasculature is involved in drug action.

The presence of an estrogen receptor in Leydig cell cytosol suggests that estrogen could have a direct action on Leydig cell function. We have shown earlier the direct effect of estradiol on testosterone biosynthesis. We report in this communication effect of estradiol on spermatogenesis using hypophysectomized rats treated daily for four days with 400 IU hCG/Pregnyl) and 1 IU FSH (Pergonal), a model that eliminates the possibility of feedback effects of estradiol on gonadotropin secretion. Estradiol was administered in subcutaneous silastic capsules. The control animals had empty capsules. The inhibition of spermatogenesis, after estradiol treatment, was marked by the presence of multinucleated giant cells, disorganization of the germinal elements, accumulation of cellular debris and the absence of late spermatid and spermatozoa. These changes in the histoarchitecture of testis were accompanied by the reduction in the diameter of the seminiferous tubules and the thickness of the basement membrane. Morphologically Leydig cells were, however, normal. Inhibition of spermatogenesis was in relation to the amount of estrogen available/administered as estradiol capsule of 0.25 cm did not evoke significant changes in the histology of the testis whereas estradiol capsule of 4 cm caused maximum damage to the spermatogenesis. Similarly progressive damage to the spermatogenesis was quite apparent as the number of days increased after estradiol capsule implantation. Neither high (1600 IU/day/4 days) nor low /5.25 IU/day) doses of hCG synergized the effect of estradiol on spermatogenesis. Testis weight was significantly reduced after estradiol treatment but weight of the epididymis and accessory sex organs did not change. Body weight was also not effected by estradiol treatment.

In immature male rats the body growth rate, the testis and epididymis weight were not affected by gossypol treatment (4, 8 and 40 mg/kg body weight/24 hrs. for 30 days). There was however a marked reduction in the weight of the prostate after high dose gossypol administration. Furthermore gossypol treatment did not show any effect on the histoarchitecture of the testis nor did the drug treatment have any effect on sperm motility. The plasma levels of testosterone, LH and FSH in gossypol treated animals were no different from those on the controls.

A significant reduction in testis, epididymis, seminal vesicles, prostate, and adrenal weight of adult rats was observed after CA treatment (10 mg/animal/day) for 13, 26 and 39 days. Biochemical assay on the epididymis showed a fall in the activities of acid and alkaline phosphatase. A significant fall in citric acid content of seminal vesicle and prostate in experimental animals was noted after CA treatment. Histoarchitecture of accessory sex organs was severely impaired.

Male rats were treated with cyproterone acetate (10 mg/day/rat) for 13, 26 and 39 days. A marked decrease in proteins, nucleic acid and phospholipid content was recorded in testis and epididymis after CA treatment. However, a significant increase in glycogen and cholesterol content in testis and epididymis was observed after CA treatment.

Effect of single oral dose (90 mg/kg body weight), multiple doses (90 mg/kg body weight for 7 days) or even higher doses (180-300 mg/kg body weight) of alpha-chlorohydrin on the testis-epididymis complex of dog, rat, cryptorchid rat, hedgehog, domestic fowl, lizard, frog, and toad has been studied. alpha-chlorohydrin treatment, at any dose, did not induce lesions in the testis-epididymis complex of dog and hedgehog having testis in scrotum and inguinal canal respectively. Abdominal testis of cryptorchid rat, domestic fowl, lizard, frog and toad also did not respond to alpha-chlorohydrin treatment. Lesions in normal rat testis-epididymis complex, after single oral dose of alpha-chlorohydrin, were quite prominent. Non-sensitivity of alpha-chlorohydrin to these animal species may be due to the absence of the pampiniform plexus complex in hedgehog and sub-mammalian animal species. Absence of conventional epididymis in the sub-mammalian animal species may be the additional reason of the non-sensitivity of the drug. Prominence of collateral blood vasculature in dog testis-epididymis complex and some alterations in the blood supply due to cryptorchidity in cryptorchid rat testis seems to be the reason of non-sensitivity of alpha-chlorohydrin to dog and cryptorchid rat testis. These observations confirm the hypothesis that the action of a single oral dose of alpha-chlorohydrin is associted with the blood vasculature of the testis-epididymis complex.

The presence of insulin-saturable binding sites in the rat testis have been demonstrated. Employing radioreceptor assay (RRA), the characteristics of insulin binding in both liver and testis of the normal (control) rats have been studied. Crude receptor binding at 37 degrees C after 18-20 hrs of incubation in Tris-HCl buffer at pH-7.5. The binding of 125I-insulin to liver and testis of the experimental rats, rendered diabetic for two months with single parenteral streptozotocin (STZ) administration (65 mg/Kg, BW, ip) was also studied. In the diabetic rats, the insulin binding in liver as compared to the control increased by over 92% (P 0.001); the increase in the binding of 125I-insulin to the testis of the diabetic rats however was not statistically significant. Similarly, insulin binding to the testis did not vary much after 3 days of starvation as against 84% (P 0.001) increase in the insulin binding to the liver of the fasted rats. These results suggest that testicular insulin receptors are similar to those of liver but may have a different physiological control.