Effect of monensin on the enzymes of oxidative stress, thiamine pyrophosphatase and DNA integrity in rat testicular cells in vitro

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.

I. The modulatory effect in genotoxic responses due to age and duration of PHT-therapy in epileptic patients

Sister chromatid exchange (SCE) frequency has been studied from the peripheral blood lymphocyte cultures of 42 epileptic patients on the anticonvulsant drug phenytoin (PHT) for 3 months and their follow-up (6 and 9 months), of 33 epileptics who had not started therapy (PHT-untreated), and of 40 normal healthy controls, all in the same age group, i.e., 10-30 years. PHT-treated epileptic patients at all three durations of therapy (3, 6, and 9 months) showed higher SCE frequency (P < 0.001) than healthy controls and PHT-untreated patients. There was no significant difference in SCE frequency between control and PHT-untreated patients, suggesting that disease is not associated with an increased frequency of SCEs. The frequency of SCEs seems to be influenced by an age factor, when older treated patients (21-30 years) showed higher SCE frequencies at 3 and 6 months (P < 0.001) and 9 months (P < 0.05) than the younger age group (10-20 years). SCE frequency increased linearly with the duration of therapy, i.e., from 3 months to 9 months. No correlation was found between SCE frequency and sex with respect to controls, PHT-untreated, and PHT-treated subjects. In conclusion, the modulating effect on SCE frequencies elicited by age and duration of therapy has been clearly demonstrated by SCE mean analysis. Teratogenesis Carcinog. Mutagen. 21:135-149, 2001.

II. An altered proliferation response due to the anticonvulsant phenytoin (PHT) in epileptic patients

Lymphocyte proliferation kinetics (LPK) is an end point used in genetic toxicology that was proposed as an alternative for the screening of anticonvulsant drugs. The effect of phenytoin (PHT) was investigated on the mitotic and proliferation indices in cultured blood lymphocytes of 33 sporadically collected untreated and 42 PHT-treated epileptics, where the duration of treatment was 3, 6, and 9 months, and 40 control subjects (age range 10-30 years). PHT induced mitotic delays and decreased the mitotic index. A significant heterogeneity of the first, second and the third metaphases between treated and untreated groups was revealed. A reduction of the proliferation index (P < 0.001) and proliferation delay per cycle (P < 0.001) was also observed. There was little variation between the controls and untreated patients (P > 0.05). The results have confirmed that PHT can affect responses leading to genotoxicity. Teratogenesis Carcinog. Mutagen. 21:151-164, 2001.

alpha-Glucosidase activity in the rat epididymis under different physiological conditions

The estimation of alpha-glucosidase activity in semen is widely used as a marker of epididymal function. In the present studies, glucosidase activity was evaluated in the different segments of the rat epididymis under various physiological conditions. In addition, the effect of two known male antifertility agents, gossypol and alpha-chlorohydrin, on enzyme activity was evaluated. Enzyme activity was absent from the epididymis of rats aged 10 and 20 days but became detectable at 30 days of age when the adult pattern of distribution (highest activity in the caput epididymis) was established. Enzyme activity was reduced significantly in all segments of the epididymis at 7 days after castration and a significant decrease in activity was also observed following the administration of either gossypol or alpha-chlorohydrin. These findings are consistent with a role for alpha-glucosidase in sperm maturation in the epididymis.

Regulation of male fertility by pyrimethamine in adult mice

Studies were carried out to determine the antifertility and reversibility effect of pyrimethamine (PYR) in adult male mice. The parameters mainly included sperm count and motility, fertility, histoarchitecture of testis and testicular cell kinetics quantitatively following oral administration of PYR (50 mg/kg body weight per day) for 30 days. The same parameters were also studied in PYR-treated animals which were allowed to recover for 45 days (recovery group). The results suggest that sperm motility as well as counts were significantly decreased in PYR-treated animals, and the fertility rate fell to zero. Testicular histology as well as germ cell kinetics were altered. However, in the animals of the recovery group, all the parameters studied were more or less similar to those of control animals. The study demonstrates the antifertility as well as reversible efficacy of PYR.

Antifertility effects of an LHRH agonist in male mice

This study was designed to investigate the effects of repeated high doses of an LHRH agonist on Swiss porton mouse seminiferous epithelium. Seminiferous epithelium showed more pronounced degenerative effects at the higher dose (1000 micrograms/kg wt/day) of the drug, with arrest of spermatogenesis at all stages of differentiation; effects on spermatogenesis become more evident after pachytene spermatocyte stage. The decrease in the testis-specific enzyme LDH-X is accounted for by the decrease in the number of cells of gametogenic origin. Although complete azoospermia was not observed, acute inhibition of motility of spermatozoa may account for severely decreased fertility rates after mating. However, reduced fertility rates due to decreased libido as a consequence of diminished testosterone levels cannot be discounted.

Spermatozoal abnormalities and male infertility in the rat following sulfasalazine treatment

OBJECTIVE

To determine the (reversible) antifertility effect in the male rat of sulfasalazine, a common therapy for inflammatory bowel disease.

METHODS

Sulfasalazine (120, 250 and 500 mg/kg) was administered for 60 days by oral gavage to sexually mature male rats.

RESULTS

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.

CONCLUSIONS

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.

Effect of human gamma interferon on mice testis: a quantitative analysis of the spermatogenic cells

Effect of Human Gamma Interferon (Hu-IFN-gamma) on the testicular histology was studied in mice. Male mice were administered Hu-IFN-gamma intratesticularly at the doses of 2, 10 and 20 micrograms/testis in a volume of 1.0 microliter isotonic normal saline. Contralateral testis served as control and was administered same amount of vehicle. All the animals were sacrificed 7 days after drug administration. Body weight and the weights of testis and epididymis were not affected by IFN treatment nor was there any effect of the drug on the motility of the vas deferens spermatozoa. Low dose of IFN (2 micrograms) did not have significant effect on the histoarchitecture of the testis and various spermatogenic elements, a progressive damage was however observed with the increasing doses of IFN. Pronounced deleterious effect of IFN on the testis leading to desquamation of the germinal epithelium, reduction in the germinal cell height and tubular diameter was observed with 20 micrograms dose. Quantitative studies on seminiferous epithelium showed a significant decrease in the number of Sertoli cells, stage-7 spermatids and stage-16 spermatozoa. The ratios of resting type spermatocyte: type A spermatogonia and stage-7 spermatids: pachytene spermatocyte was also reduced. The ratios of pachytene spermatocyte: resting spermatocyte and stage-16 spermatozoa: stage-7 spermatids were however not affected by IFN treatment. In another experiment IFN was administered (2 micrograms/day) subcutaneously to male mice for 30 days. No effect of drug treatment on body weight, organ weight, sperm motility and histology (including morphometry) of the testis was observed. Our data suggest that IFN action at testis may be associated with the antiproliferative effect of interferon.

Effect of active immunization to luteinizing-hormone-releasing hormone on the fertility and histoarchitecture of the reproductive organs of male rat

The feasibility of using a vaccine against luteinizing-hormone-releasing factor for suppression of pituitary and gonadal functions has been indicated for some time. Antibody production against this low-molecular-weight, naturally occurring decapeptide, however, requires to be coupled to a carrier protein to enhance its immunogenicity. LHRH was coupled to diphtheria toxoid (DT). Adult male Sprague-Dawley rats with a mean basal body weight of 200 g were immunized with anti-LHRH-DT (20 micrograms/injection/rat) at four-week intervals. An equal number of unexposed animals served as controls. Six animals were killed every two weeks up the end of the week 43. The vaccination schedule did not have any effect on the gain in body weight, nor was any adverse effect of vaccination observed in the course of the investigations. The pituitary, prostate, epididymis, testes, seminal vesicles, adrenal and thyroid were excised for determination of organ weight and histological examination. The adrenal, pituitary and thyroid showed no remarkable weight changes during the observation period, whereas the weights of the reproductive organs demonstrated significant reductions compared to those of the control group. The histopathology revealed marked to significant changes in the gonads and the accessory sex organs including the prostate. A progressive phase of regeneration of spermatogenesis was evident 98 days after vaccination. Total recovery of spermatogenesis was observed 300 days after vaccination. The mating studies showed the return of fertility 300 days after vaccination. The litters borne were normal. Prostate showed recovery after 154 days of vaccination. Our observations lend strong support to the hypothesis that anti-LHRH vaccine can be effectively used on the management of prostate carcinoma. If the vaccination is given together with a suitable dose of long-acting androgen, contained in an adequate delivery system, the regimen may be used for the regulation of male fertility.

Effect of sulphapyridine on male fertility in the rat

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.

Effect of optical isomers of gossypol on mammalian spermatozoa: an in vitro study

Human, bull and monkey spermatozoa were treated with different optical isomers of gossypol in vitro. The spermatozoa (concentration 50 x 10(8)) were incubated with gossypol for 15, 30, 45 and 60 min. at 37 degrees C. The concentration of gossypol employed in the experiment was from 5-50 micrograms/ml. A marked inhibition in sperm motility was observed following gossypol treatment; levorotatory gossypol had more pronounced effect on sperm motility in comparison to dextrorotatory and racemic gossypol. Scanning electron microscope study revealed degenerative changes in the sperm head surface. Dextrorotatory gossypol, hitherto known to be non-effective in suppressing the fertility in vivo was found to be equally effective in inhibiting the motility and LDH-X activity of the spermatozoa. Both racemic and dextrorotatory gossypol inhibited fructolysis in bull spermatozoa. Our data suggest that whatever the mechanism of action of enantiomers of gossypol on sperm motility, fructolysis and LDH-X may be, it is evidently clear that dextrorotatory gossypol is equally active in inhibiting the sperm motility and enzyme active in vitro. The action of optical isomers of gossypol on spermatozoa in vitro, appears to be unrelated to the mechanism of orally administered gossypol.

65Zn incorporation in the male reproductive organs following gossypol treatment

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.

Distribution of gossypol

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.

Effect of gossypol on rats maintained on protein deficient and low potassium diets

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.

Effect of gossypol on domestic fowl, Gallus domesticus

Domestic fowls (Gallus domesticus) were administered gossypol (10 mg/kg body weight/day) by oral intubation for 15 weeks. Drug treatment did not have any effect on body growth rate. The drug treatment, however, caused a marked decrease in the weights of testis and epididymis. Predominant changes in the histoarchitecture of testis (desquamation of germinal epithelium and inhibition of spermatogenesis) were observed following gossypol treatment. Epididymal tubules in gossypol treated animals were devoid of spermatozoa. Gossypol treatment had no effect on hematological parameters (total erythrocyte count, total leucocyte count, hematocrit and hemoglobin) studied in the present investigations.

Early events in rat testis after gossypol administration

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.

Effect of gossypol on the fertility of male rats

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)

Recovery of normal testis function and sperm motility after cessation of gossypol treatment in hamster

The present investigations evaluate the reversibility of the effect of gossypol on the histoarchitecture of the hamster testis and the motility of the vas deferens spermatozoa. Adult male hamsters of proven fertility were treated orally with gossypol (10 mg/kg/day) for 13 weeks (group III). Another group of animals in the Group IV were given gossypol (10 mg/kg/day) for 13 weeks and were sacrificed 13 weeks after termination of the drug treatment. Animals in groups I and II were given vehicle and served as controls for groups III and IV respectively. To all the animals, gossypol or vehicle was administered by oral intubation. A marked reduction in the spermatozoa motility was observed in the animals of group III. In contrast, the motility of the spermatozoa in the animals of group IV (recovery phase) was in the normal range. A large number of seminiferous tubules were affected by gossypol treatment (group III); these tubules showed degeneration of germ cells, vacuolization and loosening of the germinal epithelium. In the quantitative analysis of the spermatogenic events, the ratio of resting spermatocyte/'A' type spermatogonia was not affected but the ratios of pachytene spermatocytes/resting spermatocytes and stage 19 spermatids/stage 7 spermatids decreased by 21%, 47% and 52% respectively. The tubular diameter and germinal height were decreased by 14% and 33% respectively. In group IV, hamsters were allowed to recover from the gossypol treatment. The seminiferous tubules exhibited normal histoarchitecture and the tubular diameter and germinal height recovered markedly. Recovery in different stages of spermatogenic cycle was evidently clear in this group.(ABSTRACT TRUNCATED AT 250 WORDS)

Characterization of specific insulin binding sites in rat testis following induced diabetes and experimental starvation

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.

The effect of gossypol acetic acid on the different stages of the spermatogenic cycle in the rat

The reversibility of the effect of gossypol on testicular histology and fertility was studied in rats. Adult males of proven fertility were treated orally with gossypol acetic acid (15 mg/kg) for 9 or 16 weeks (groups 1 and 2, respectively). Another groups of animals (group 3) was given gossypol (15 mg/kg) for 16 weeks and killed 6 weeks after the end of treatment. Control animals (group 4) were given the vehicle only by oral intubation. In the mating studies, although only 33% of the animals in group 1 were infertile, 100% infertility was observed following 16 weeks of gossypol treatment (group 2). All animals in group 3 regained their fertility 6 weeks after cessation of drug treatment. Damage was observed to 15.7% of the seminiferous tubules after 9 weeks of drug treatment, and to 78% after 16 weeks of treatment. Extensive vacuolization, increased numbers of lipid droplets, degeneration of germ cells, loosening of the epithelium, and a significant decrease in the number of pachytene spermatocytes (stages VII-X) and spermatids (steps 7-10 at stages VII-X) were observed after gossypol treatment. There was a decrease in the diameter of only stage VIII seminiferous tubules after 9 weeks of treatment, whereas a reduction was observed in the tubules of all stages after 16 weeks of gossypol treatment. In the recovery phase, the diameter of seminiferous tubules was similar to that of controls, except for tubules at stage VIII. No change in the area of the lumen of the seminiferous tubules and lipid bodies was observed after 9 weeks of drug treatment, but a marked reduction in the area of the lumen (stages II-X) and an increase in lipid bodies (all stages) was observed after 16 weeks of gossypol treatment. Six weeks after cessation of treatment, the area of the lumen and the number of lipid bodies were comparable to values in controls. A reduction in the area of the epithelium was restricted to just a few stages (VIII-XIV) in treated animals at 9 weeks, whereas after 16 weeks the area of the epithelium was decreased in all tubules. In the recovery phase, except for tubules at stage VIII, the area of the seminiferous epithelium was comparable to that in controls.

Assay of Testosterone, FSH and LH in Serum and Spermogram in Leprosy Patients

Testicular functions in the form of testosterone, FSH and LH levels in serum by radio-immuno-assays, complete semen examination and a few testicular biopsies were studied in 30 men with leprosy (LL-7, BL-6, BB-1, BT-12 and 'fT-4). Serum testosterone levels were lowered in all the groups. Serum FSH and LH levels were elevated in lepromatous and borderline .1epromatous leprosy. Semen analysis showed oligospermia in LL and BL groups. Lepra bacilli in smars of semen were present in 2 LL case. Leprous changes were seen in the testicular biopsies.