Effect of prolactin on testicular lipid metabolism in pubertal rats

Prolactin administration for 7 day to pubertal rats resulted in marked depletion of total lipids, phospholipids and particularly phosphatidyl choline and phosphatidyl ethanolamine. There was a concomitant increase in total cholesterol and cholesterol ester with a fall in free cholesterol. The increase in total cholesterol in the testis of prolactin-treated animals appears not to be due to its increased synthesis, as the hormonal treatment had no significant effect on HMG-Co A reductase, the rate limiting enzyme of sterol synthesis. Prolactin also had no significant effect on the enzymes glucose-6-phosphate dehydrogenase, malic- and isocitrate dehydrogenases reported to generate NADPH required for active steroidogenesis. Thus, it appears that the fall observed in testicular phospholipids and free cholesterol with concurrent increases in total cholesterol and cholesterol ester after prolactin administration is not due to prolactin's effect directly on testicular lipid metabolism in pubertal rats.     

Effects of a cholesterol esterase inhibitor and of prostaglandin F2α on testis cholesterol and on plasma testosterone in mice

Administration of Phenylmethylsulfonylfluoride, an inhibitor of cholesterol esterase, to male mice caused an increase in the concentration of esterified cholesterol in the testis, a decrease in the weight of seminal vesicles and a decrease in the concentration of testosterone in peripheral plasma. It is suggested that hydrolysis of cholesterol esters present in the testis is required for normal production of androgenic steroids.Administration of prostaglandin F_2α to male mice lowered plasma testosterone levels and raised the concentration of esterified cholesterol in the testes. Apparently testicular steroidogenesis was inhibited.     

Hormonal influence on testicular lipids.

The effects of progesterone and progesterone plus oestrogen (PPO) on testicular lipids of adult rats were studied. Treatment with progesterone over 7 days did not alter significantly the total lipids, cholesterol, glycerides and phospholipids. However, PPO administration brought about a significant elevation in total lipids, mainly contributed by the increase in triglycerides. The phospholipids and total cholesterol were not markedly affected by PPO treatment, but the individual classes of phospholipids showed marked alterations in their pattern of distribution. The esterified and free cholesterol fractions were found to be significantly altered by both the treatments. Progesterone appears to favour ester cholesterol accumulation by depleting the available free cholesterol. Oestrogen seems to increase the glycerides and change the concentration of phosphatidyl serine, phosphatidyl choline and phosphatidyl ethanolamine when administered with progesterone.     

Effects of prolactin and androgens on seminal vesicular lipids of castrated mature bonnet monkeys Macaca radiata

Effects of prolactin (PRL), bromocriptine (Br), testosterone propionate (TP), dihydrotestosterone (DHT) and the combination of these androgens with PRL/Br on the total lipid, total cholesterol, total glyceride glycerols, total phospholipid and their fractions in seminal vesicles of castrated mature monkeys were studied. Glyceride glycerols formed the major portion (50%) of total lipids in normal monkeys. Cholesterol and phospholipids were of equal share (25%). Esterified cholesterol formed major share (75%) of total cholesterol. Diacyl glycerol was the major (60%) glyceride glycerol and phosphatidyl choline and ethanolamine were the major phospholipid classes. Except triacyl glycerol castration markedly decreased all the lipid classes. PRL restored normal free and esterified cholesterol and phosphatidyl inositol but Br invariably decreased all the lipid classes. TP/DHT treatment stimulated the free and esterified cholesterol more than the control; it restored the normal glyceride glycerols. Phosphatidyl inositol, choline and ethanolamine were stimulated by androgens and other phospholipid classes were brought to normal. Addition of PRL + TP/DHT markedly increased esterified cholesterol, phosphatidyl inositol, choline, ethanolamine and phosphatidic acid. In all these aspects, Br counteracted the effects of androgens and PRL.     

Effects of ovine LH, GH and prolactin, and testosterone on serum testosterone and estradiol-17 beta levels, and seminal vesicle and testicular activity in the catfish Clarias batrachus (L.)

Intraperitoneal administrations of testosterone (0.5 microgram/g body wt), and ovine LH (1.0 microgram/g body wt), GH (5 micrograms/g body wt) and prolactin (10 micrograms/g body wt) daily for 7 days during early prespawning phase (May) in C. batrachus produced varied effects on seminal vesicle (SVSI) and testicular (GSI) weights and biochemical correlates. Testosterone and LH treatments significantly increased serum testosterone level and concentrations of total proteins, fructose, hexosamines and sialic acid in both seminal vesicles and testis. Serum E2 levels increased significantly only after testosterone treatment. GH treatment increased significantly serum testosterone level and only the concentrations of SV hexosamines and testicular protein. Prolactin, however, significantly lowered serum testosterone level and concentrations of total protein, hexosamines in both SV and testis, and testicular fructose and sialic acid levels. The results show that the stimulating effect of LH and GH on SV and testicular activity is mediated through the increased secretion of testosterone and the inhibitory effect of prolactin by decreased testosterone secretion.     

Aminoglutethimide inhibits steroidogenesis in the rat testis

Aminoglutethimide inhibits steroid formation in the adrenal and in the ovary but it is not established whether it has a similar effect in the testis. Adult male rats were injected with 10 mg or 15 mg amino-gluthethimide phosphate (AGP) per 100 g body weight twice daily for 3$\text{1}\text{2}$ days and killed 3 hrs or 5 hrs after the last injection. Treatment with either dose of AGP caused a precipitous decrease in plasma testosterone levels. Administration of the higher dose of AGP also caused a decrease in seminal vesicles weight and an increase in the concentration of esterified cholesterol in the testes. The results indicate that aminoglutethimide inhibits testicular steroidogenesis.     

Impact of hyperprolactinaemia on testicular neutral lipids and phospholipids in mature bonnet monkeys, Macaca radiata (Geoffroy)

Impact of hyperprolactinaemia, induced by daily injection of ovine prolactin (250 micrograms/kg body weight, ip for 30 days) on testicular lipids was studied in M. radiata. Wet weights of testis and accessory sex organs decreased in hyperprolactinaemic monkeys. Even though total lipids in the testis did not show any significant change, total cholesterol and total glyceride glycerol decreased. While all fractions of testicular neutral lipids showed a perceptible decrease, phosphatidic acid, phosphatidyl ethanolamine and phosphatidyl choline increased in hyperprolactinaemic monkeys. Hyperprolactinaemia appears to influence male fertility by altering the composition of testicular neutral lipids and phospholipids.     

Effects of Malva viscus conzattii Greenm flower extract on testicular function of the house rat Rattus rattus Rufescens & the gerbil Meriones hurrianae Jerdon: a biochemical study

Extract of the flower Malva viscus conzattii (M. conzattii) was administered at a dose of 25/50 mg/day/animal to 30 healthy adult male gerbils and 30 adult male house rats to determine its effect on fertility. After 25 days' treatment fin l body weight, and the weights of testes, epididymides, seminal vesicles, and adrenal glands were measured. Testis, epididymides, and seminal vesicles were prepared for histological examination and total protein, RNA, sialic acid, and alkaline phosphatase activity were determined. Quantitative estimation of cholesterol was also made. While overall body weight remained stable during treatment, testicular weight in both animals was drastically decreased. A complete spermatogenic arrest in the testes was evident in house rats treated with 50 mg/day for 20 days and in the gerbil treated with 25 mg/day for 25 days. The seminiferous tubules showed marked degeneration, lined by 1 or 2 cell layers. Epididymides showed degenerative changes as well. RNA contents of the testes, epididydmides, and seminal vesicles of treated anials were significantly lowered as was sialilc acid content. Total cholesterol was increased significantly. M. conzattii causes an effective inhibition of spermatogenesis in gerbils and house rats in 25 states and induces infertility.     

Effects of a single ethanol injection into the vas deferens on the testicular function of rats.

1. A new approach to rapid male sterilization has been studied by giving a single injection of 95% ethanol directly into the vas deferens. It produced an effective block in the lumen. The mating exposure test showed that the males were sterile. The sperm granulomas at the site of vas injection were confirmed. 2. Ethanol injection in the vas deferens caused an atrophy of the testes. Extensive necrosis and exfoliation of the seminiferous elements were conspicuous. 3. Decrease in testicular weight, seminiferous tubule diameter and RNA and sialic acid levels after 4 weeks of vas injection were associated with the histological evidence for severe degeneration of spermatogenic elements. The protein contents of testis, epididymides and seminal vesicles did not change. 4. Testicular cholesterol, total lipids and alkaline phosphatase activity was increased. 5. Low sialic acid levels in the testis, epididymides and seminal vesicles of vas-injected rats indicated an inhibition of androgen production, which was further reflected in reduced nuclear diameters of leydig cells.     

Morphology of the male reproductive systems of two Indopacific blenniid fishes,Salarias fasciatus and Ecsenius bicolor (Blenniidae,Teleostei)1

The testes and associated accessory organs of two blenniid fishes are described. The testicular organs of Salarias fasciatus consist of a testicular gland adjacent to the testis, chambered seminal vesicles serving as a reservoir for spermatozoa and testicular blind ouches. Ecsenirts bicolor has no testicular gland, has elongated chambered seminal vesicles whii are not used as a reservoir for spermatozoa, and has testicular blind pouches.     

Role of thyroid on testicular lipids in prepubertal, pubertal and adult rats. I. Hyperthyroidism

The influence of thyroxine-induced hyperthyroidism on testicular neutral and phospholipids was studied in prepubertal, pubertal and adult rats. Thyroxine treatment (25 micrograms/100 g body weight) for 1 month decreased testicular total lipids, total glyceride glycerols, total cholesterol and total phospholipids. Different classes of glyceride glycerol, cholesterol and phospholipid were also diminished due to thyroxine treatment. All classes of lipids returned to the euthyroid level after the withdrawal of thyroxine treatment. The data obtained in the present study suggest that thyroid hormones have a definite influence on testicular lipid metabolism in rats.     

The lipid composition of human testis in testicular feminization syndrome

Testicular tissues obtained from 12 cases of testicular feminization syndrome were subjected to lipid analyses. The total lipids formed 2.75% of the total wet weight of the testicular tissue. Total cholesterol represented 30%, glycerides 33% and phospholipids 37% of the total lipids, respectively. Fractionation studies revealed that free cholesterol formed 66.7% and esterified cholesterol 33.3% of the total cholesterol. Triglycerides represented 89.89% and monoglycerides 10.11% of the total glycerides. Separation of phospholipids showed that phosphatidly choline (46.54%) and phosphatidly ethanolamine (24.89%) to be the major phosphoipid classes.     

Effect of progesterone on rat plasma and liver lipid levels (author's transl)

The effect of progesterone upon several lipidic parameters on rat liver and plasma was studied. Progesterone administration led to a significant increase in the hepatic triacylglyceride and cholesterol esterified levels and to a decrease in the phospholipid content. After progesterone treatment decreases in plasma total lipids, phospholipids, cholesterol and cholesterol esterified were observed, whereas plasma triacylglyceride and free fatty acid levels increased. The hormonal treatment altered the lipoprotein pattern, which significantly reduced the beta-lipoprotein fraction.     

Male reproductive effect of nickel sulphate in mice

Nickel sulphate was administered orally to adult male mice at dose level of 5 and 10 mg/kg body weight (5 days per week) for 35 days. There was no change in body weight. However a significant decrease in absolute and organ-to-body weight ratios of testes, epididymides, seminal vesicles and prostate gland was observed. The sperm abnormality, associated with decrease in sperm motility and sperm count was also observed. Significant alterations in the activities of marker testicular enzymes, viz. sorbitol dehydrogenase (decreases), lactate dehydrogenase (increases) and -glutamyl transpeptidase (increases) associated with histopathological changes in testes, epididymides and seminal vesicles, were also observed. Accumulation of nickel in testes, epididymides and seminal vesicles was also observed. The study reveals that the oral exposure to nickel may affect the histology of testes, epididymides, seminal vesicles and sperms morphology. These testicular and spermatotoxic changes may be responsible for observed male mediated developmental toxic effects.     

Effects of flutamide on testicular involution induced by an antagonist of gonadotrophin-releasing hormone and on stimulation of spermatogenesis by follicle-stimulating hormone in rats.

The effects of combined treatment with an antagonist of gonadotrophin-releasing hormone (ANT) and the antiandrogen flutamide (FL) on spermatogenesis were studied in the presence and absence of exogenous follicle-stimulating hormone (FSH). After treatment for 2 weeks, the combination of ANT (RS 68439, 450-500 micrograms/kg per day, s.c.) with 10, 20 or 40 mg FL/day, s.c. was as effective as ANT plus the Leydig cell toxin ethane dimethane sulphonate (75 mg/kg per week, i.p.) in terms of reduction in weight of testes, epididymides and seminal vesicles. Thus, a daily dose of 10 mg FL/kg was sufficient to block the androgen action in the testes of ANT-treated rats. In a second experiment, rats received ANT and ANT+FL (10 mg/kg) alone or in combination with a highly purified human FSH preparation (5 or 10 iu, twice a day) for 2 weeks. FSH did not affect testosterone concentration or weight of epididymides and seminal vesicles, but ANT+FL markedly enhanced the ANT-induced reduction of testis weight, seminiferous tubule diameter and numbers of germ cells, as revealed by qualitative and quantitative analysis of testis histology. In the absence of FL, testis size and numbers of germ cells, including elongated spermatids, were increased by FSH. In the presence of FL, the effects of FSH were less pronounced with respect to the germ cells, in terms of both numbers of cells and the effective dose of FSH. Irrespective of treatment with FL, exogenous FSH increased the inhibin concentrations in serum, indicating that Sertoli cells remained responsive to FSH. From the present study it is concluded that (i) FL accelerates ANT-induced testicular involution, (ii) FSH has a role in adult spermatogenesis and (iii) the effects of FSH on advanced germ cells are influenced by androgens.     

Genetic architecture of testis and seminal vesicle weights in mice

Comparisons across 13 inbred strains of laboratory mice for reproductive organ (paired seminal vesicles and paired testes) weights indicated a very marked contrast between the C57BL/6By and NZB/BINJ mice. Subsequently these strains were selected to perform a quantitative genetic analysis and full genome scan for seminal vesicle and testis weights. An F(2) population was generated. The quantitative genetic analyses indicated that each was linked to several genes. Sixty-six short sequences for length polymorphism were used as markers in the wide genome scan strategy. For weight of paired testes, heritability was 82.3% of the total variance and five QTL contributed to 72.8% of the total variance. Three reached a highly significant threshold (>4.5) and were mapped on chromosome X (LOD score 9.11), chromosome 4 (LOD score 5.96), chromosome 10 (LOD score 5.81); two QTL were suggested: chromosome 13 (LOD score 3.10) and chromosome 18 (LOD score 2.80). Heritability for weight of seminal vesicles was 50.7%. One QTL was mapped on chromosome 4 (LOD score 9.21) and contributed to 24.2% of the total variance. The distance of this QTL to the centromere encompassed the distance of the QTL linked with testicular weight on chromosome 4, suggesting common genetic mechanisms as expected from correlations in the F(2). Both testis and seminal vesicle weights were associated with a reduction in the NZB/BINJ when this strain carried the Y(NPAR) from CBA/H whereas the Y(NPAR) from NZB/BINJ in the CBA/H strain did not modify reproductive organ weights, indicating that the Y(NPAR) interacts with the non-Y(NPAR) genes. The effects generated by this chromosomal region were significant but small in size.     

Effects of physiological and abnormally elevated prolactin levels on the pituitary-testicular axis

Prolactin can influence testicular function both directly, and indirectly via altering release of gonadotropins from the pituitary. Although numerous effects of prolactin on male reproductive functions have been described, only a few were demonstrated in more than one species. These include effects on male accessory reproductive glands, on testicular luteinizing hormone receptors, on the release of gonadotropins and on sexual behavior. In rodents, prolactin appears to play a physiological role in the pituitary regulation of testicular function. This is especially pronounced in the golden hamster. In this seasonally-breeding species, alteration of prolactin release is one of the mechanisms mediating the effects of photoperiod on the testis. In the hamster, prolactin is required for the maintenance of luteinizing hormone and prolactin receptors in the testis and treatment with prolactin can completely reverse testicular atrophy induced by exposure to short photoperiod. In both men and rats, excessive release of prolactin (hyperprolactinemia) leads to suppression of sexual behavior and gonadotropin release. These effects appear to be due to the action of prolactin on the central nervous system. Most, if not all, of the effects of prolactin exhibit striking variability among species. Moreover, prolactin can exert differential effects on the same target tissue in the same species, depending primarily on the dose.     

Gossypol and testicular lipids of adult rats

Testicular lipids act as source of energy, structural components of spermatozoa and precursors of androgen biosynthesis. Treatment with antispermatogeneic agents cause accumulation of testicular lipids. Gossypol, an effective antispermatogenic agent causes marked accumulation of testicular neutral lipids. It did not affect testicular phospholipids. Gossypol treatment did not bring about marked changes in the key enzymes like HMG Co A reductase, glucose-6-phosphate dehydrogenase malic enzyme and cytosolic isocitrate dehydrogenase involved in sterol biosynthesis. Thus, gossypol brings about marked accumulation of glycerides and esterified cholesterol in the testis due to its effect on spermatogenic elements of adult rats.     

Effect of chronic treatment with phenobarbital or 3-methylcholanthrene on the male reproductive system in rats

Treatment of rats for 4 weeks with phenobarbital (PB) did not inhibit the growth of the seminal vesicles, nor did it affect the biosynthesis of testosterone by testis microsomes. Moreover, neither the concentration of cytochrome p-450 or the 17 α-hydroxylase activity in testis microsomes were affected. In contrast, treatment with 3-methylcholanthrene (3-MC) for 4 weeks markedly decreased the weights of the seminal vesicles. The decrease was probably related to an impairmant of testosterone formation in the gonads, since testosterone biosynthesis as well as the concentration of cytochrome p-450 and the activity of 17 α-hydroxylase in testis microsomes were significantly decreased in the 3-MC treated rats. No histopathological changes were seen in testes from any of the PB or 3-MC treated rats.     

Structure of the ellipsoid sheath in the spleen of the armadillo (Dasypus novemcinctus). A light and electron microscopic study

A seasonal study of the seminal vesicles in relation to that of the testes had been conducted in the catfish, H. fossilis. The annual reproductive cycle of the catfish has been divided into (i) Preparatory period (February–April), (ii) Prespawning period (May–June), (iii) Spawning period (July–August) and (iv) Postspawning period (September–January). Testes exhibit initiation of spermatogenesis in the mid-preparatory period, but significant increase in weight of the testes accompanied by active spermatogenesis occurs during the prespawning period. In the spawning period, the testes are maximally enlarged and their seminiferous tubules are packed with spermatozoa. Following spawning, the testes gradually regress in the postspawning period. The seminal vesicles show initiation of secretory activity during the preparatory period but their recrudescence lags behind that of the testes by about a month. The seminal vesicles attain maximum weight and secretory activity during the spawning period. Thereafter, the seminal vesicles regress precipitously and sooner than the testes. The histochemical and biochemical studies on the seminal vesicles indicate that the secretion contains mucoproteins, acid mucopolysaccharides, primary proteoses, besides traces of phospholipids and native proteins.