Gamma-glutamyl transpeptidase activity in the epididymis during fetal and postnatal development in rats.

The histochemical and biochemical distributions of gamma-glutamyl transpeptidase (gamma-GT) were investigated in the epididymis of rats during fetal and postnatal development. In the epididymal homogenates, gamma-GT activity was detected on the fifth day after birth. A sharp increase was observed after 30 days of life in the caput homogenates. Moderate levels of the enzyme were found in the cauda epididymis. Gamma-GT is histochemically detected from the 15th day of gestation in Wolffian ducts and in 17- to 18-day-old fetuses in newly differentiated epididymal tubules. Enzyme activity, was associated with the plasma membranes (apical, lateral, and basal), was preponderant on the apical part of the epithelial cells. During the first 15 days of the postnatal life, the histochemical reaction intensities were identical from the caput to the cauda epididymidis. From the 18th day onwards, enzyme activity decreased in the corpus and in the cauda, while gamma-GT increased in the caput epididymidis, and a strong activity was found on the apical surface of epithelial cells. Weak or moderate gamma-GT activity of spermatozoa in the caput tubules, increasing steadily from caput to cauda epididymidis, suggests that gamma-GT may be related to the functional maturation of spermatozoa.     

Expression and regulation of aquaporins 1, 8, and 9 in the testis,efferent ducts,and epididymis of adult rats and during postnatal development

Aquaporins (AQPs) are membrane protein channels that allow the rapid passage of water through an epithelium containing tight junctions. In the present study, light microscope immunocytochemistry was utilized to localize several members of the AQP family in the testis, efferent ducts, and epididymis of normal adult animals during postnatal development and after various experimental procedures on adult animals. In the testis of normal adult animals, AQP-8 was expressed exclusively in Sertoli cells, while AQP-9 outlined Leydig cells. In the efferent ducts, AQP-1 was expressed on the microvilli, basolateral plasma membranes, and apical endosomes of the nonciliated cells and cilia of ciliated cells, while AQP-9 was present only on the microvilli of nonciliated cells. In the epididymis, AQP-9 was localized to the microvilli of the principal cells of all regions, with the most intense reaction being noted in the initial segment and cauda regions. The clear cells of the cauda region expressed only AQP-9. AQP-1 was not expressed in the testis or the epididymal epithelium, but it was expressed over the endothelial cells of the vascular channels of the efferent ducts and epididymis. After efferent duct ligation or orchidectomy, there was no change in the expression of AQP-1 or -9 over the microvilli or cilia of epithelial cells in the case of the efferent ducts, suggesting that testicular factors do not regulate their expression in this region. In contrast, AQP-9 expression in the principal cells of the initial segment, but not of other regions, and also in the clear cells of the cauda region was dramatically reduced after both treatments. As the expression was not restored to control levels by testosterone replacement, the data suggest that a luminal factor(s) derived from the testis regulates AQP-9 expression in the principal cells of the initial segment and in the clear cells of the cauda region. Postnatal studies revealed that the expression of AQP-1 and -9 in the different cell types of the efferent ducts and epididymis occurred between days 7 and 29, eliminating sperm and high androgen levels as possible regulating factors. Taken together, these data suggest cell specificity with respect to the expression of AQP-8 and -9 in the testis. In the efferent ducts and epididymis, specificity exists in cell, region, and tissue distribution with respect to the expression of AQP-1 and -9, and their expression does not appear to be regulated by androgens.     

Regional Differences in Steroidogenesis and Hormone Levels in the Epididymis and Vas Deferens of Adult Rats

In vivo and in vitro studies with different parts of the epididymis and vas deferens were carried out to determine their inherent capacity to synthesize steroids and to correlate with the endogenous levels with or without the administration of hCG.
Incubation with ¹⁴C-labelled pregnenolone and testosterone demonstrated that caput epididymidis was more active than other parts in synthesizing testosterone from ¹⁴C-pregnenolone and in converting labelled testosterone to 5α-dihydrotestosterone (DHT). The cauda epididymidis and vas deferens accumulated more radioactivity in progesterone and dehydroepiandrosterone (DHEA) than the caput epididymidis.
The levels of DHT, testosterone and 4-androstene-3,17-dione in the caput epididymidis were reduced after ligation of ipselateral efferent ductules indicating the testicular origin of these steroids. The cauda epididymidis and vas deferens had higher levels of progesterone as compared to the other regions of the epididymis, which were decreased after the ligation. Intravenous injection of hCG increased the levels of oestradiol-17β in all tissues and markedly in the cauda epididymidis and vas deferens. The high levels of progesterone and oestradiol-17β present in these organs may be of importance in maintaining fertilizing ability of spermatozoa stored in the cauda epididymidis and vas deferens and their transport.     

Circulating and luminal testicular factors affect LRP-2 and Apo J expression in the epididymis following efferent duct ligation

Apolipoprotein J (clusterin or sulfated glycoprotein-2) has been shown to be secreted by the epididymal principal cells, whereupon it binds to sperm in the lumen. Apolipoprotein J also is endocytosed by principal cells along the epididymis. Recently, it has been demonstrated that low-density lipoprotein receptor-related protein-2 (LRP-2) mediates the endocytosis of Apo J and is present in the epididymis. The purpose of the present study was to determine the factors regulating the synthesis of these 2 proteins in various experimentally treated animals. The epididymides of adult rats were fixed with Bouin's fluid and examined with anti-Apo J and anti-LRP-2 antibodies by a light microscope immunocytochemical method. In normal adult animals, expression of Apo J was evident in principal cells of all epididymal regions except the proximal initial segment. Diffuse cytoplasmic staining indicated Apo J secretion. Reactive apical vesicles, presumably endosomal in nature, suggested endocytosis of Apo J. Lipoprotein receptor-related protein-2 expression was solely apical in nature and was seen as an intense apical band in principal cells of all regions except the proximal and distal initial segment and distal caput regions of the epididymis. Hypophysectomy, up to 28 days after the procedure, did not affect expression of Apo J or LRP-2 in principal cells along the entire epididymis. Orchidectomy, with or without testosterone replacement at all time intervals examined, also did not affect LRP-2 expression along the entire epididymis. This also was noted for Apo J expression in all regions except the proximal initial segment. Thus, expression of these 2 proteins does not appear to be regulated by testicular or pituitary factors. In contrast, bilateral as well as unilateral (intact and ligated sides) efferent duct ligation resulted in dramatic differences in LRP-2 and Apo J expression in principal cells in the various epididymal regions. In the case of LRP-2, a complete absence of reaction was noted in principal cells along the entire epididymis. As for Apo J, expression in the distal initial segment, intermediate zone, and caput region remained unchanged compared with that in normal adult animals, whereas in the corpus and cauda epididymides, results of cytoplasmic staining were negligible. These results suggest that under conditions of efferent duct ligation, a circulating factor emanates from the testis to inhibit expression of LRP-2 and Apo J in these epididymal regions. Furthermore, because Apo J was affected in a region-specific manner, unlike the case for LRP-2, different factors appear to be involved for each protein. These factors may be produced to inhibit proteins from being synthesized by the epididymis in the absence of luminal testicular input and may exist in cases of congenital and pathologic epididymal tubule blockages as well as after vasectomy. In the case of immunostaining for Apo J in the proximal initial segment only, normally unreactive principal cells in control adult animals became intensely reactive after orchidectomy as well as bilateral and unilateral (ligated side only) ligation. As this was not the case for hypophysectomized animals and the intact side of unilateral efferent duct-ligated animals, it is suggested that a testicular factor entering via the lumen of the efferent ducts serves to inhibit Apo J expression in this area. The present data also reveal that after efferent duct ligation, there are circulating factors that inhibit Apo J expression in a region-specific manner (corpus and cauda) and that inhibit LRP-2 expression along the entire epididymis and that these are derived from the testis. Furthermore, the data reveal that a testicular luminal factor appears to inhibit Apo J expression in the proximal initial segment of normal adult animals. Key words: Principal cells, orchidectomy, glycoprotein 330, clusterin, sulfated glycoprotein-2.     

Immunolocalization and regulation of cystic fibrosis transmembrane conductance regulator in the adult rat epididymis

Cystic fibrosis is the most common serious autosomal recessive condition in whites, and more than 95% of men with cystic fibrosis are infertile. The cystic fibrosis transmembrane conductance regulator (CFTR), a cyclic adenosine monophosphate (cAMP)-regulated chloride channel, has been localized in the efferent ducts; however, to our knowledge, its expression and regulation in the epididymis by testicular factors have not been examined. In the present study, these parameters were examined immunocytochemically by the light microscope with an anti-CFTR antibody in Bouin-fixed, paraffin-embedded control adult rat epididymides and both orchidectomized adult rats with or without testosterone supplementation and efferent duct-ligated rats sacrificed at different time points. In control animals, a thick dense band of immunoperoxidase reaction product was visualized over the apical plasma membrane of the principal cells but not their microvilli. The apical band was prominent only in the corpus and cauda regions. While there was no CFTR expression in basal cells, clear cells of the corpus and cauda regions showed a weak-to-moderate band of apical plasma membrane staining. An examination of orchidectomized, orchidectomized and testosterone, and efferent duct-ligated rats revealed that CFTR was no longer expressed as an intense band on the apical plasma membrane of the principal cells of the corpus and cauda regions. However, under these conditions, an intense apical/supranuclear reaction was noted in the form of small vesicular structures. Clear cells were unaffected by the different experimental treatments. Together, these data indicate that CFTR is expressed in a cell- and region-specific manner and that, while its synthesis in principal cells is not under the control of testicular factors, targeting to the apical plasma membrane is regulated by a testicular luminal factor.     

Factors Affecting Blood Levels of Androgen Binding Protein in the Rat

The factors which determine the levels of androgen binding protein (ABP) in blood were studied. Serum ABP concentrations are high at 18 days of age and decline, after formation of the blood-testis barrier, to levels found in adults. Secretion of ABP into the epididymis was markedly decreased in H^re rats and animals with Sertoli cell enriched testis, but the serum concentrations were normal. Serum ABP concentrations increase following obstruction of the efferent ducts and decrease following hemicastration. Testosterone treatment of chronically hypophysectomized rats resulted in an increase in testicular and serum ABP concentrations but no change in epididymal levels. By contrast, treatment with testosterone and FSH caused an increase in the epididymal content many-fold greater than that observed in plasma. These observations are consistent with the hypothesis that release of ABP into blood is controlled by factors which are independent of transport to the epididymis.     

Immunolocalization of the Yb1 subunit of glutathione S-transferase in the adult rat epididymis following orchidectomy and efferent duct ligation

In addition to the maturation of sperm, the epididymis also serves to protect sperm from harmful reactive oxygen species. To this end, various antioxidant enzymes are produced by the epididymis, such as glutathione S-transferases (GSTs), a family of dimeric proteins that catalyze the conjugation of glutathione to various electrophilic compounds, thus providing cellular detoxification. In the present study, the regulation of the Yb(1) subunit of GST was examined in Bouin-fixed epididymides of adult control, orchidectomized (O) rats with or without testosterone (T) supplementation and efferent duct-ligated (EDL) rats using light microscope immunocytochemistry with an anti-Yb(1)-GST antibody. The intensely reactive ciliated cells of the efferent ducts and principal cells of the epididymis showing a checkerboard staining pattern were unaltered in their expression of Yb(1)-GST after all experimental procedures, suggesting their regulation by factors other than of testicular origin. On the other hand, the intense reaction of narrow/apical cells and moderate reaction of basal cells of the proximal initial segment of control animals became negligible in O rats and was not restored with T supplementation. As staining was also absent after EDL, the data suggest that a luminal testicular factor(s), other than androgens, regulates expression of Yb(1)-GST in narrow/apical and basal cells of the proximal initial segment. Although basal cells of the caput and cauda epididymidis were unreactive after all experimental protocols, as also noted in controls, the intensely reactive basal cells of the corpus epididymidis of control animals became unreactive in O animals. However, Yb(1)-GST expression was restored to these cells with T supplementation, and as there was no effect on Yb(1)-GST expression after EDL, the data suggest that circulating testosterone or one of its metabolites regulates expression of Yb(1)-GST in basal cells of the corpus region. Taken together, these data indicate a differential regulation with respect to the expression of Yb(1)-GST in the various cell types and regions of the epididymis.     

Differential effect of hyperthyroidism on rat epididymal glycosidases

The impact of hyperthyroidism on epididymal glycosidases was studied in albino rats. Hyperthyroidism was induced in Wistar rats aged 30 days by daily injection of T4 (25 microg/100 g body weight/day intramuscularly) for 30 or 60 days; control rats were injected with vehicle (alkaline saline, pH 7.8). One set of hyperthyroid rats was reverted to euthyroid status by withdrawing T4 treatment after 30 days of hyperthyroidism. To asses the direct effect of thyroid hormone on epididymal hexosaminidases, caput, corpus and cauda tissues were stimulated with 25, 50 or 100 ng/mL T3 for 24 h, after an initial culture of 24 h. The activity of beta-glucosidase decreased in caput, corpus and cauda epididymis of hyperthyroid rats. beta-Galactosidase activity increased in the caput epididymis irrespective of the duration of hyperthyroidism. While a similar decrease occurred in the corpus and cauda epididymis in the 30 day hyperthyroid group, an opposite trend was observed in 60 day hyperthyroid rats. Caput beta-N-acetylglucosaminidase activities increased at both time points, whereas activity decreased in the corpus and cauda in 30 day, but increased in 60 day hyperthyroid rats. Hyperthyroidism consistently increased caput and corpus beta-N-acetylgalactosaminidase activity irrespective of the duration. Cauda epididymal beta-N-acetylgalactosaminidase activity was decreased in 30 day and increased in 60 day hyperthyroid rats. Hyperthyroidism induced changes in caput beta-galactosidase, beta-N-acetylgalactosaminidases, corpus beta-N-acetylglucosaminidase and cauda beta-N-acetylgalactosaminidase which were irreversible while the remaining actvities were brought back to normal when T4 treatment was withdrawn. In vitro studies showed that T3 stimulates epididymal hexosaminidases (beta-N-acetylglucosaminidase and beta-N-acetylgalactosaminidase) irrespective of the dose. These data suggest that thyroid hormones have a specific and direct influence on glycosidases in specific regions of the epididymis.     

Glutathione, L-glutamic acid and γ-glutamyl transpeptidase in the bull reproductive tissues

The distribution of glutathione (GSH), L-glutamic acid (Glu) and gamma-glutamyl transpeptidase (gamma-GT) was studied in bull reproductive organs and fluids. Glutathione, the physiological substrate of gamma-GT, was localized specifically by a fluorescence method in the testis, epididymis and spermatozoa. Of the reproductive tissues, the testis, caput epididymis and ampulla had the highest levels of GSH, but it was also present in seminal fluid. Washed caput epididymal sperm had three times the GSH content of cauda epididymal or ejaculated sperm. In spermatozoa, GSH displayed maximal staining in the midpiece and tail regions. The highest levels of gamma-GT were encountered in the epididymis. The concentration of Glu was also high in the epididymis. Its formation may be due to the hydrolytic activity of gamma-GT, which, in addition, may have an important role in the transfer of Glu residues to reactive groups on the sperm surface.     

Selective action of androgens on the molecular forms of esterases characterized by two-dimensional gel electrophoresis in the epididymis and vas deferens of the mouse

Molecular forms of esterases were resolved in non-denaturing conditions by using two-dimensional gel electrophoresis with isoelectric focusing in the first dimension and a time-dependent polyacrylamide gradient gel electrophoresis (PAGGE) in the second dimension. This procedure was used to analyse sequential changes in esterase composition along the excurrent genital duct of the mouse and to initiate a specific identification of the androgen-regulated molecular forms. Almost all the 68 variants (pH 3.9-6.4 and 50-300 kDa) revealed by alpha-naphtyl acetate from the fluids of the three parts of the epididymis (caput, corpus, cauda) and vas deferens, could be assigned to the carboxylesterase group as shown by their action on various substrates and sensitivity to inhibitors. Some of these variants co-migrated with those in the serum and testis, whereas other enzyme forms made their first appearance in the caput (13), in the corpus (26) and in the vas deferens (3). The major changes occurred between the caput and the corpus of the epididymis. Only a few acidic spots were not revealed after neuraminidase digestion. Castration of mice (4 weeks) resulted in inhibition of the activity of 34 esterase forms, and thus abolished most of the regional differences in the excurrent duct system. By re-initiating or repressing the synthesis of regional esterase variants, testosterone supplementation (2 and/or 4 weeks) of castrated animals restored the normal esterase pattern in the three epididymal parts, but not in the vas deferens. The major effect of efferent duct ligation (4 weeks) was the emergence in the corpus and cauda of the epididymis of two variants found in the caput of uncastrated mice.     

Effect of adrenalectomy on rat epididymidis

Aim:To investigate the effect of adrenalectomy (ADX) on the epididymidis of Sprague-Dawley rats.Methods:The histological,biochemical(cholesterol protein,zinc,copper,alkaline and acid phosphatase aryl sulphatase,lactic dehydrogenase and leucine amino peptidase)and hormonal (FSH,LH and testosterone) changes of caput and cauda epididymis in ADX rats were observed.Results:Organ wet weight,histological studies and morphometric measurements indicated a cellular degeneration in caput and cauda epididymis of ADX rats.Serum testosterone level was significantly lower in ADX than in sham-operated rats,while the serum FSH and LH were below the detection limit of 1 mIU/mL.The enzymatic activity was higher in ADX than in sham-operated rats.Epididymal zinc level increased whereas copper level decreased in ADX rats compared to the sham-operated.Conclusion:Adrenalectomy leads to degeneration of caput and cauda epididymidis epithelial cells as a result of decreased supply of testosterone.     

Testicular regulation of epididymal protein secretion.

The effects of different androgen and testicular fluid levels on the protein synthesis and secretion of the epididymis of mice and rats were examined. In mice, the in vitro protein synthesis and secretion of five epididymal segments were measured from 3 days up to 8 weeks after efferent duct ligation. During the entire period, alterations in the rate of protein secretion per milligram tissue were small. At 8 weeks, the mean rate of protein synthesis per milligram ligated epididymal tissue was 80% of that of the control side. As a consequence of the weight loss of the ligated epididymis, however, the protein secretion per organ can be estimated to be reduced by 50%. Changes in the protein profile were only found in the proximal segment, where a 40-kd protein appeared and a 29-kd protein disappeared. In rats, the effects of efferent duct ligation were studied in vivo for up to 8 months. Structural changes were present both in the proximal and in the distal epididymis. The most conspicuous change in the protein profile of secretory proteins was the disappearance of a 27-kd protein from the proximal segment. In the distal epididymis, a 32-kd protein was no longer secreted. In mice, the effects of castration on the profile of secreted proteins demonstrated that, without androgen stimulation, some proteins are still secreted 6 weeks after castration. Administering low or high doses of testosterone propionate to castrated mice resulted in almost similar profiles of secretory proteins. However one protein secreted in the proximal epididymis was preferentially stimulated by the high dose of testosterone propionate.     

Acid hydrolases in the epididymis of normal, castrated, vasectomized, cryptorchid and cryptepididymal rats

With the aim of gaining knowledge about the lysosomal apparatus of the rat epididymis, four acid hydrolases were analysed in homogenates of the whole organ and, in other experiments, in separated segments: proximal and distal caput, corpus and cauda. The activities were similar to those in the liver, and they were 50% recovered in a cytosol of 43 000 g x 60 min. Ten days after castration all segments showed similar changes, the activities of beta-glucuronidase and cathepsin D increased above normal levels while those of DNAase and acid phosphatase were found slightly decreased. After vasectomy region I (caput and corpus) showed decreased beta-glucuronidase activity and increased acid phosphatase activity. The activity of cathepsin D increased in both regions. In cryptorchid rats (90 days) the epididymis greatly decreased in weight, the activities of acid phosphatase and DNAase slightly decreased in region II (cauda) and in region I, respectively. In the abdominal epididymis (90 days) only region II decreased in weight. DNAase activity decreased in region I while cathepsin D did so in both regions. The results showed that a) the enzymes behave quite independently from each other, suggesting the existence of a specific regulation for each of them b) there were characteristic changes in enzymatic activity for each experimental condition.     

In vitro Metabolism of (3H)-Androstenedione in the Rat Epididymis and Vas Deferens

The in vitro metabolism of (3H)-androstenedione in the epididymis and vas deferens of intact and castrated rats was investigated and the metabolites formed were identified by radio gas chromatography. Incubation of slices of caput epididymidis for 2 hr at 34 degrees C metabolised 90% androstenedione. Similar incubations of tissue samples from cauda epididymidis and vas deferens metabolized 60 and 25% of androstenedione respectively. The major metabolites formed in the epididymis were androstanedione (caput: 48%; cauda: 33%) and androsterone (caput: 35%; cauda: 13%). These metabolites appeared in much less concentration in the incubations with vas deferens (about 8% each). In general, conversion to testosterone and dihydrotesterone was low in all the three organs examined. Castration did not significantly alter the metabolic pattern in the caput epididymidis and vas deferens but promoted the formation of androsterone (38%) in the cauda epididymidis. The conversion of androstenedione, a weak androgen to testosterone, dihydrotestosterone and 3 alpha/3 beta-diols in the epididymidis and vas deferens of castrated rats may be of physiological significance. In addition, androsterone appears to be an important androgenic metabolite in the epididymis.     

Effect of adrenalectomy on rat epididymidis

Aim: To investigate the effect of adrenalectomy (ADX) on the epididymidis of Sprague-Dawley rats. Methods: The histological, biochemical (cholesterol protein, zinc, copper, alkaline and acid phosphatase aryl sulphatase, lactic dehydrogenase and leucine amino peptidase) and hormonal (FSH, LH and testosterone) changes of caput and cauda epididymis in ADX rats were observed. Results: Organ wet weight, histological studies and morphometric measurements indicated a cellular degeneration in caput and cauda epididymis of ADX rats. Serum testosterone level was significantly lower in ADX than in sham-operated rats, while the serum FSH and LH were below the detection limit of 1 mIU/mL. The enzymatic activity was higher in ADX than in sham-operated rats. Epididymal zinc level increased whereas copper level decreased in ADX rats compared to the sham-operated. Conclusion: Adrenalectomy leads to degeneration of caput and cauda epididymidis epithelial cells as a result of decreased supply of testosterone. (Asian J And     

Nonprotein thiols and disulfides in rat epididymal spermatozoa and epididymal fluid: role of gamma-glutamyl-transpeptidase in sperm maturation

Sperm thiol oxidation during sperm maturation is important for sperm component stabilization, the acquisition of sperm motility, and fertilizing ability. A correct degree of oxidation is required, since spermatozoa are very susceptible to oxidative damage. The pathways involved in physiologic sperm thiol oxidation in the epididymis are not completely understood. The nonprotein thiol glutathione (GSH), in addition to playing a major role as an antioxidant and in eliminating toxic compounds, has been implicated in prooxidation processes in various cells, via gamma-glutamyl-transpeptidase (gamma-GT)-dependent catabolism. Little information is available on the dynamics of nonprotein thiols (NPSHs) and disulfides (NPSSNPs) in spermatozoa and epididymal fluid (EF) during sperm passage in the epididymis. It is not clear whether NPSHs and NPSSNPs are involved in sperm protein thiol (PSH) oxidation or whether GSH catabolism in the epididymis can serve as a pathway for sperm PSH oxidation. In the present study, we used the thiol fluorescence labeling agent monobromobimane to analyze NPSHs and nonprotein disulfides (NPSSRs) (R, nonprotein or protein) in spermatozoa and EF in the rat caput and cauda epididymis. NPSH levels are shown to be significantly higher in the caput than in the cauda (spermatozoa and fluid). GSH in the caput lumen is subject to high gamma-GT activity. A marked loss of sperm GSH and a shift to an oxidized state (resulting in a significantly higher concentration of glutathione disulfides [GSSRs] than GSH) occur during the passage of spermatozoa from the caput to the cauda epididymis. Caput EF and extracellular NPSSNPs induce sperm thiol oxidation. The results suggest that epididymal NPSH/NPSSNP participates in sperm PSH oxidation and that some reactions of GSH in the gamma-GT pathway (in the epididymis) provide oxidizing power, leading to physiologic sperm thiol oxidation.     

Acid hydrolases in the epididymis of normal, castrated, vasectomized, cryptorchid and cryptepididymal rats

With the aim of gaining knowledge about the lysosomal apparatus of the rat epididymis, four acid hydrolases were analysed in homogenates of the whole organ and, in other experiments, in separated segments: proximal and distal caput, corpus and cauda. The activities were similar to those in the liver, and they were 50% recovered in a cytosol of 43 000 g × 60 min. Ten days after castration all segments showed similar changes, the activities of β-glucuronidase and cathepsin D increased above normal levels while those of DNAase and acid phosphatase were found slightly decreased. After vasectomy region I (caput and corpus) showed decreased β-glucuronidase activity and increased acid phosphatase activity. The activity of cathepsin D increased in both regions. In cryptorchid rats (90 days) the epididymis greatly decreased in weight, the activities of acid phosphatase and DNAase slightly decreased in region II (cauda) and in region I, respectively. In the abdominal epididymis (90 days) only region II decreased in weight. DNAase activity decreased in region I while cathepsin D did so in both regions. The results showed that a) the enzymes behave quite independently from each other, suggesting the existence of a specific regulation for each of them b) there were characteristic changes in enzymatic activity for each experimental condition.     

Zinc Content in Epididymal Spermatozoa of Metoclopramide-Treated Rats

Zinc content was determined separately in spermatozoa taken from epididymal caput and cauda in rats. It was revealed that spermatozoa transported from the epididymal caput to the cauda reduce about 54% of zinc. This reduction is significantly inhibited in spermatozoa of rats receiving metoclopramide. That is also accompanied by a fall of testosterone level in blood serum and of delta 5, 3 beta-HSD activity in Leydig cells. It was found out that the reduction of zinc in spermatozoa at the time of their passage through the epididymis is the process that depends on androgens.