Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “EPIDIDYMITIS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 253 records · Page 14Linked to original sources
PubMed1998

[Epididymal manifestations of urogenital tuberculosis].

OBJECTIVE: To define the epidemiological, anatomical, clinical and therapeutic aspects of tuberculous epididymitis in adults in the tropics. MATERIAL AND METHODS: This was a retrospective study of 11 cases of confirmed and treated tuberculous epididymitis. RESULTS: The most frequently affected age-group was 40-49 years. The commonest expression was that of a chronic epididymal nodule. The diagnosis was confirmed by histological examination of the epididymectomy specimen (10 cases) and bacteriology in one case. Combination antituberculous chemotherapy was systematically administered and epididymectomy was performed in all patients. CONCLUSION: The diagnosis of tuberculous epididymitis is often very difficult in the absence of a history of recent or active tuberculosis. However, this diagnosis must be considered in any case of chronic epididymal nodule, particularly in a context of infertility. The very mutilating treatment consists of epididymectomy in chronic forms, which also constitutes a diagnostic confirmation procedure, hence the value of prevention based on eradication of tuberculosis.

Adult↗
PubMedDate not supplied

Evaluation of ICSI-selected epididymal sperm samples of obstructive azoospermic males by the CKIA system.

The objective of this study was to evaluate nuclear normality in intracytoplasmic sperm injection (ICSI)-selected epididymal sperm from obstructive azoospermic (OA) patients. We evaluated whether the selection criteria used in routine ICSI (morphology and motility at a magnification of 400x) is adequate for selecting "normal" sperm from epididymal samples. Surgically retrieved spermatozoa from the caput epididymis of 15 OA patients and ejaculated sperm samples from 9 normospermic donors were evaluated with a DNA-specific stain (Feulgen) and in combination with the computerized karyometric image analysis (CKIA) system. Original (unselected) samples and ICSI-selected sperm were compared in donor and patient samples. In the original fraction, a larger variation in almost all measured parameters was found in epididymal sperm than in ejaculated sperm. After sperm selection, the morphometry was comparable between epididymal and ejaculated sperm. However, for those parameters related to the DNA stainability and chromatin texture (nuclear condensation), significant differences between patients and donors were observed. This result suggests that the size and form of the sperm do not necessarily hold similar internal structures. Thus, the frequency of "normal" sperm significantly increased after ICSI selection, but the improvement was more marked in donor than in OA patients' samples. In conclusion, at least a twofold increase in the number of normal spermatozoa was achieved after ICSI selection. The heterogeneity in the stainability and chromatin condensation of epididymal samples from OA patients indicates that some of the selected spermatozoa have a hypocondensed or hypercondensed chromatin. Even in the best of donor cases, no more than 55% of the selected sperm scored normal with CKIA, indicating that the present routine ICSI selection criteria are not sufficient for selecting normal condensed nuclei.

Ejaculation↗
PubMed1994

Morphological characteristics of boar efferent ductules and epididymal duct.

The aim of the present study was to provide a comprehensive morphological analysis of the porcine epididymis in view of the specific functions being performed in different regions of this organ. Blood supply and microvasculature of efferent ductules and epididymal duct were investigated by means of corrosion casts which were analysed macroscopically and by scanning electron microscopy. This revealed blood supply to the testis and epididymis to be closely related. The capillary pattern was typical for the efferent ductules, the caput, corpus, and distal cauda epididymidis, respectively. Corrosion casts were also used to visualize the course of the efferent ductules themselves. Tissue samples from different regions of the efferent ductules and epididymal duct were examined by light microscopy and both scanning and transmission electron microscopy, with special attention being payed to transitional areas. Morphological criteria allowed the distinction of three segments within the efferent ductules and of the initial segment, proximal caput, distal caput, corpus, proximal cauda, and distal cauda regions of the epididymal duct. Components of the endocytic apparatus of efferent ductule principal cells were identified by ferritin uptake. Ultrastructural evidence of absorption in the epididymal duct was particularly prominent in proximal and distal caput. Extensive cisternae of rough endoplasmic reticulum and a well-developed Golgi apparatus were indicative of active protein synthesis and secretion especially in the distal caput and corpus regions. However, assignment of various organelles in principal cells of the epididymal duct to either absorptive or secretory pathways still remains tentative.

Animals↗
PubMed1995

Epididymal epithelium: its contribution to the formation of a luminal fluid microenvironment.

To understand the process of sperm maturation, an understanding of interactions between the spermatozoa with the luminal fluid microenvironment and with the epididymal epithelium is necessary. The composition of epididymal luminal fluid of several species is well documented but the manner by which the epididymis contributes to the formation of this specialized milieu is not so well understood. A major role played by the epididymis is to finely regulate the movement of molecules into and out of the lumen. This ensures that as spermatozoa progress along the duct they are exposed to a continually changing, but optimal environment necessary for their maturation and survival. This review focusses on our current understanding of the contributions of the epididymal epithelium to the formation of a specialized luminal fluid microenvironment. The role of the blood-epididymis barrier, the composition of the epididymal luminal fluid, the permeability properties of the epididymal epithelium, and recent studies on a number of luminal fluid proteins and expression of the genes which encode these proteins are discussed.

Animals↗
PubMed1988

Epididymal microsurgery: current techniques and new horizons.

Surgical treatment for obstructive azoospermia was introduced about 30 years ago with the development of Bayle's vasoepididymal fistula technique (Bayle: Enc Med Chir 41:435, 1966). More recently this has been replaced by single tubule end-to-end microvasoepididymal bypass procedures with improved success rates. We describe the use of animal models in the development and application of a modified end-to-end microanastomosis technique in which the vas deferens is attached to a single surface convolution of the ductus epididymidis. In comparison with other microvasoepididymostomy (micro-VE) procedures, this technique results in less postoperative scarring and allows for easier access to the epididymis in those patients requiring subsequent epididymal surgery. With this procedure 60% of patients produced spermatozoa after operation, and 10% of 102 patients have so far achieved pregnancies. For patients, such as those with congenital absence of the vasa deferentia, whose infertility cannot be corrected by microvasoepididymal surgery, we describe a microaspiration procedure that can be used to collect spermatozoa from the epididymis for use in in vitro fertilization (IVF). This procedure has a low success rate at present, with an 18% fertilization and 3% pregnancy rate per cycle. Improvements in treatment procedures for aspirated sperm samples, such as the use of motility stimulators and in vitro maturation by coculture with epididymal tubule segments before IVF, may enhance the success for this technique. Microinjection of sperm collected by epididymal microaspiration into oocytes may be an alternative method of treatment for these patients in the future. Two procedures (microepididymoepididymostomy and the vas bridge bypass) that are currently being modelled in the rabbit may provide new directions for epididymal microsurgery and for examining epididymal function. Although the two methods are technically more difficult than standard micro-VE procedures, preliminary studies are encouraging and suggest a future role for these techniques in treating obstructive azoospermia. Such techniques make use of the epididymis distal to the obstruction site and may be particularly important in improving the success of surgery for obstructive azoospermic patients with high-level obstructions in whom sperm quality following micro-VE surgery is often poor.

Anastomosis, Surgical↗
PubMed1995

Transient appearance of CRES protein during spermatogenesis and caput epididymal sperm maturation.

In previous studies we identified an epididymal gene that exhibits homology to the cystatin family of cysteine protease inhibitors. The expression of this gene, termed CRES (cystatin-related epididymal and spermatogenic), was shown to be highly restricted to the proximal caput epididymal epithelium with less expression in the testis and no expression in the 24 other tissues examined. In this report, studies were carried out to examine CRES gene expression in the testis as well as to characterize the CRES protein in the testis and epididymis. In situ hybridization experiments revealed that within the testis CRES gene expression is stage-specific during spermatogenesis and is exclusively expressed by the round spermatids of Stages VII-VIII and the early elongating spermatids of Stages IX and X. Immunohistochemical studies demonstrated that CRES protein was transiently expressed in both the testis and epididymis. Within the testis the protein was localized to the elongating spermatids, whereas within the epididymis CRES protein was exclusively synthesized by the proximal caput epithelium and then secreted into the lumen. Surprisingly, the secreted CRES protein had completely disappeared from the epididymal lumen by the distal caput epididymidis. Western blot analysis of testicular and epididymal proteins showed that the CRES antibody specifically recognized a predominant 19 kDa CRES protein and a less abundant 14 kDa form. These observations suggest that the CRES protein performs a specialized role during sperm development and maturation.

Animals↗
PubMed1988

Low molecular weight factor in bovine caudal epididymal fluid that stimulates calcium uptake in caput spermatozoa.

Secretions from the mammalian epididymis contain proteins that bind to developing sperm and are presumed to play a role in sperm maturation. The biochemical functions in sperm of most of these proteins are not known. In this report we describe the presence of a low molecular weight compound in bovine caudal epididymal luminal fluid (CF) that has a potent stimulatory effect on calcium (45Ca2+) uptake in immature caput epididymal spermatozoa. The studies were initially undertaken to characterize the effect of the protein caltrin, present in bovine seminal plasma (BSP), on calcium uptake into caput spermatozoa. Caltrin is known to block calcium influx into mature bovine sperm. Unexpectedly, the kinetics of calcium uptake into caput sperm showed a biphasic response when treated with BSP, namely, a stimulation of uptake at 1 to 5 min and inhibition of uptake after this time. Since caudal sperm do not show this biphasic response, we reasoned that BSP contained a factor derived from CF that must interact with developing sperm before the binding of caltrin to sperm can prevent further calcium uptake. We first demonstrated that preincubation of caput sperm with CF eliminated the biphasic calcium uptake effect induced in caput sperm by BSP and that caudal fluid alone had a potent stimulatory effect on calcium uptake in caput sperm. Half-maximal stimulation (fivefold over control) occurred at a caudal fluid protein concentration of 0.27 mg/ml. Partial purification of the factor indicates that it is of low molecular weight (MW approximately 1,000), but further chemical characterization has not been carried out and its epididymal site of origin is not known. The results indicate that the regulation of intracellular calcium levels in sperm differs in immature and mature bovine sperm in that an epididymal factor promotes calcium uptake during epididymal maturation, and the seminal fluid protein caltrin prevents it at ejaculation.

Animals↗
PubMed2002

Direct injection of foreign DNA into mouse testis as a possible in vivo gene transfer system via epididymal spermatozoa.

We have attempted to transfect testicular spermatozoa with plasmid DNA by direct injection into testes to obtain transgenic animals [this technique was thus termed "testis-mediated gene transfer (TMGT)"]. When injected males were mated with superovulated females 2 and 3 days after injection, (i) high efficiencies (more than 50%) of gene transmission were achieved in the mid-gestational F0 fetuses, (ii) the copy number of plasmid DNA in the fetuses was estimated to be less than 1 copy per diploid cell, and (iii) overt gene expression was not found in these fetuses. These findings suggest the possibility that plasmid DNA introduced into a testis is rapidly transported to the epididymis and then incorporated by epididymal spermatozoa. The purpose of this study was to elucidate the mechanism of TMGT by introducing trypan blue (TB) or Hoechst 33342 directly into testis. We found that TB is transported to the ducts of the caput epididymis via rete testis within 1 min after testis injection, and TB reached the corpus and cauda epididymis within 2-4 days after injection. Staining of spermatozoa isolated from any portion of epididymis was observed 4 days after injection of a solution containing Hoechst 33342. Injection of enhanced green fluorescent protein (EGFP) expression vector/liposome complex into testis resulted in transfection of epithelial cells of epididymal ducts facing the lumen, although the transfection efficiency appeared to be low. In vivo electroporation toward the caput epididymis immediately after injection of EGFP expression vector into a testis greatly improved the uptake of foreign DNA by the epididymal epithelial cells. PCR analysis using spermatozoa isolated from corpus and cauda epididymis 4 days after injection of a DNA/liposome complex into testis revealed exogenous DNA in these spermatozoa even after treatment with DNase I. These findings indicate that exogenous DNA introduced into tesits is rapidly transported to epididymal ducts via the rete testis and efferent ducts, and then incorporated by epithelial cells of epididymis and epididymal spermatozoa.

Animals↗
PubMed1983

Localization of lectin receptors on bovine epididymal spermatozoa using a colloidal gold technique.

Mammalian spermatozoa that leave the testis are neither motile nor fertile. Maturation of spermatozoa occurs during epididymal transport. Among the changes during epididymal passage alterations of the surface properties of spermatozoa appear especially interesting. In this report we describe ultrastructural localization of Con A and WGA-binding sites on bovine spermatozoa from caput and cauda epididymides using a indirect lectin-horse-radish-peroxidase gold technique. With Con A the plasma-membrane covering the sperm head was heavily labelled with gold granules in caput as well as in cauda epididymal spermatozoa. A different distribution was observed for WGA-binding sites. The acrosomal region of caput and cauda spermatozoa was heavily labelled with gold, both in caput and cauda spermatozoa. The postacrosomal region was only sparsely marked in caput sperm whereas in sperm cells originating from the cauda a calix like membrane area displayed intense labelling. Some differences in the number of binding sites were also seen on sperm tails: those of caput spermatozoa show generally more Con A binding sites that those from cauda epididymal spermatozoa. No changes in the number of WGA-binding sites on sperm tails was observed during epididymal passage. The technical aspects of the indirect lectin-horse-radish-peroxidase gold technique are briefly discussed.

Animals↗
PubMed1989

Identification of cholesta-7,24-dien-3 beta-ol and desmosterol in hamster cauda epididymal spermatozoa.

The sterol composition of hamster cauda epididymal spermatozoa was remarkably different from that of several other mammalian spermatozoa. Desmosterol and cholesta-7,24-dien-3 beta-ol account for as much as 90% of the total sterols. Cholesterol and desmosterol are the major components of mouse cauda epididymal spermatozoa, and rabbit, boar and bull ejaculated spermatozoa. Cholesta-7,24-dien-3 beta-ol was not detected. Furthermore, cholesterol was the main sterol in hamster caput epididymal spermatozoa, while only a trace amount of desmosterol was detected and cholesta-7,24-dien-3 beta-ol was hardly detected at all. The sterol content of cauda and caput epididymal spermatozoa was 0.17 +/- 0.05 mumol/10(8) spermatozoa. During maturation, the desmosterol and cholesta-7,24-dien-3 beta-ol levels increase and the cholesterol level decreases. Cholesta-7,24-dien-3 beta-ol appears as a sterol in mature spermatozoa and seems to be a characteristic sterol of hamster cauda epididymal spermatozoa.

Animals↗
PubMed1984

Effect of D-valine and cytosine arabinoside on [3H]thymidine incorporation in rat and rabbit epididymal epithelial cell cultures.

Epithelial cell enriched primary cultures were established from the rat and the rabbit epididymis. Epithelial cell aggregates, obtained after pronase digestion of minced epididymis, attached to the culture dish and after 72 h in vitro spread out to form discrete patches of cells. These cells have an epithelioid morphology and form a monolayer of closely apposed polygonal cells where DNA synthesis, as judged by [3H]thymidine uptake, is very low. In L-valine medium the nonepithelial cell contamination was no more than 10% in rat and rabbit epididymal primary cultures. The labeling index of rat epididymal cells cultured in D-valine medium was significantly lower than that of cells cultured in L-valine medium. In contrast, the labeling index of rabbit epididymal cells cultured in D-valine medium was significantly higher than that of cells cultured in L-valine medium. Cytosine arabinoside decreased the number of labeled cells in both L-valine and D-valine cultures. From these results, it appears that D-valine is a selective agent for rat epididymal epithelial cells, but not for rabbit epithelial cells, and that cytosine arabinoside is a simple and effective means to control the proliferation of fibroblast-like cells in both rat and rabbit epididymal cell cultures.

Animals↗
PubMed2004

Possible involvement of microtubules and microfilaments of the epididymal epithelial cells in 17beta-estradiol synthesis.

The rat epididymal epithelial cells revealed features of steroidogenic cells and released 17beta-estradiol (E2) into the culture medium. In steroidogenic cells, elements of the cytoskeleton due to their influence on organelle distribution are implicated in the regulation of steroidogenesis. In the present study, the morphology of cultured epididymal epithelial cells in light, scanning and transmission electron microscopes was evaluated. The organization of microtubules and microfilaments revealed by fluorescence microscopy, and the concentration of E2 in cultured medium were also studied. The epididymal epithelial cells were cultured in different conditions: in the medium with or without exogenous testosterone (T) and in the co-culture with Leydig cells as a source of androgens. The cells in co-culture located close to Leydig cells were rich in glycogen, PAS-positive substances and lipid droplets, in higher amount than the cells cultured with addition of exogenous testosterone. Stress fibers and microtubules of epididymal epithelial cells cultured with exogenous T and in co-culture with Leydig cells presented typical structure, and numerous granular protrusions appeared on the surface of the cells. Disorganization of microtubules and shortening of stress fibers as well as the smooth cell surface deprived of granular protrusions were observed in the epididymal epithelial cells cultured without T. Change of the cytoskeleton organization caused by the absence of androgen in culture medium resulted in an increased E2 secretion.

Actin Cytoskeleton↗
PubMed2002

Effect of nonylphenol on the antioxidant system in epididymal sperm of rats.

Nonylphenol, an environmental contaminant, has been shown to induce reproductive abnormalities in male rats. The nature and mechanism of action of nonylphenol on the epididymal sperm has not been elucidated. In the present study we have sought to investigate whether administration of nonylphenol induces oxidative stress in rat epididymal sperm. Nonylphenol was administered orally to male rats at 1, 10 and 100 microg/kg body weight per day for 45 days. Twenty-four hours after the last treatment, rats were weighed and killed using anaesthetic ether. The body weight of the animals treated with nonylphenol did not show any significant change. The weights of the testes and epididymides decreased significantly whereas the weights of seminal vesicles and ventral prostate remained unchanged at all doses of nonylphenol in treated rats. Epididymal sperm were collected by cutting the epididymides into small pieces in Ham's F-12 medium at 32 degrees C. Administration of nonylphenol decreased the epididymal sperm counts in a dose-dependent manner. The activities of antioxidant enzymes superoxide dismutase, catalase, glutathione reductase and glutathione peroxidase decreased significantly while the levels of H(2)O(2) generation and lipid peroxidation increased significantly in the animals treated with nonylphenol when expressed in terms of milligram protein and milligram DNA. The activity of alpha-glucosidase, a negative control against antioxidant enzymes, in the sperm of nonylphenol-treated rats did not show any significant change at any of the doses. The results suggest that graded doses of nonylphenol elicit depletion of antioxidant defence system in sperm, indicating nonylphenol-induced oxidative stress in the epididymal sperm of rats.

Animals↗
PubMed2004

Rat sperm AS-A: subcellular localization in testis and epididymis and surface distribution in epididymal sperm.

In this study, we investigated the subcellular compartmentalization of arylsulfatase-A (AS-A) in the testis and epididymis as well as the surface distribution in rat epididymal sperm. Testicular AS-A was compartmentalized specifically to the area underneath the outer acrosomal membrane of the acrosomal granule and to the dorsal aspect of the sperm acrosome. Epididymal AS-A was synthesized in the endoplasmic reticular (ER) network of principal cells and secreted into epididymal lumen as evident by its reactivity in the apical cytoplasm and vesicles therein underneath stereocilia. In clear cells, AS-A reactivity was found throughout the cytoplasmic machineries involved in endocytosis. Surface distribution of AS-A was initially detectable at the concave ridge as early as in sperm of the initial segment (IS). AS-A was additionally localized to the post-acrosomal region in caput (CP), corpus (CO) and cauda (CD) epididymal sperm. The expression levels of surface AS-A gradually increased during sperm transit from IS to CD epididymidis. These results favored the adsorption of AS-A from epididymal fluid onto the sperm surface, rather than shunting from the acrosome as a consequence of capacitation-associated membrane priming.

Animals↗
PubMed1988

The effect of ornidazole on fertility and epididymal sperm function in rats.

A comprehensive study of male fertility and sperm production and function was performed in 20 control and 20 rats treated with ornidazole, a compound with trichomonacidal activity. Rats were treated for 4 weeks at dosages of 0 (control) and 400 mg/kg/day of ornidazole during which fertility was assessed by weekly matings. Testicular sperm production and epididymal sperm function were assessed in one-half of the rats while the reversibility of effects after a 2-week recovery period was assessed in the remaining half. Male rats treated with ornidazole were infertile during the second week of treatment. After 4 weeks of treatment, testicular and epididymal weights, testicular spermatid counts, epididymal sperm reserves, sperm morphology, and sperm viability were similar in treated and control rats. A quantitative assessment of epididymal sperm motility using a dark-field photomicroscope with a stroboscopic light source revealed that ornidazole markedly inhibited sperm motility. Although the percentage of nonmotile sperm was not substantially increased in treated rats, the vigor of tail movement was markedly decreased which resulted in decreased sperm velocity. Restoration of fertility and normal sperm motility and velocity were observed in the group of recovery rats assessed 2 weeks after the cessation of ornidazole treatment. It is concluded that ornidazole, at a high dosage of 400 mg/kg/day, produces infertility in male rats by inhibiting epididymal sperm motility in terms of decreased sperm velocity. These effects are rapidly reversible after the cessation of treatment.

Animals↗
PubMed1996

Testicular and epididymal function during the peripuberal period in Brahman bulls receiving various amounts of protein degradable in the rumen.

Thirty-nine Brahman bulls with an initial age and weight of 301.7 +/- 4.1 d and 202.7 +/- 4.7 kg, respectively, were randomly allocated to 1 of 2 dietary treatment groups within age, weight and sire in order to study the influence of source of protein and stage of peripuberal period on testicular and epididymal function. In the soybean meal treatment the amount of protein undegradable in the rumen averaged 47%, while it was 72% in the fish meal treatment. The supplements were isocaloric and isonitrogenous. Bulls were electroejaculated, and castrations were performed randomly in a predetermined order when the first ejaculate with the first motile sperm cells (Stage 1), 10 to 25 million (Stage 2), and 50 million or more sperm cells (Stage 3 - puberty) was obtained. Testicular and epididymal traits were analyzed for a single testicle and epididymis. Daily sperm production, daily sperm production per gram of testicular parenchyma, testicular weight and testicular parenchyma weight were not affected by treatment. Bulls receiving fish meal had heavier (P < 0.01) epididymis than soybean meal-fed bulls (6.6 +/- 1.0 vs 3.9 +/- 0.6 g) but similar (P > 0.05) epididymal sperm reserves. Daily sperm production (1 testicle) was 115.2 +/- 0.1, 447.4 +/- 0.1, 792.7 +/- 0.1 million sperm cells, and daily sperm production per gram of testicular parenchyma was 1.5 +/- 0.5, 3.2 +/- 0.6 and 6.4 +/- 0.6 million sperm cells for bulls at Stage 1, 2 and 3, respectively. Sire and amount of undegradable intake protein had significant (P < 0.05) affects on the distribution of epididymal sperm reserves, with soybean meal-fed bulls having the higher proportions of epididymal sperm reserves in the cauda epididymis.

Journal Article↗
PubMed1990

The stroma-vascular fraction of rat inguinal and epididymal adipose tissue and the adipoconversion of fat cell precursors in primary culture.

The stroma-vascular fraction (SVF) of inguinal and epididymal fat pads of 4 week-old rats was studied by electron microscopy. Among the various cell types, endothelial cells and preadipocytes were found in both SVF, while mesothelial cells were only detected in the epididymal SVF. The resulting heterogeneity of primary culture and the adipoconversion of the fat cell precursors were studied in a serum-supplemented medium enriched with insulin (14.5 nM) and exogenous triglycerides. Despite the heterogeneity of the inoculum, the primary cultures were rather homogeneous, fat cell precursors being the main cell type. Distinctive contaminant fibroblast-like cells were observed in both cultures, whereas epithelial-like cells, which correspond most probably to mesothelial cells, were only found in epididymal cultures. Differentiation of fat cell precursors was assessed by the appearance of lipoprotein lipase (LPL) and glycerol-3-phosphate dehydrogenase (GPDH). LPL activity was found in the same level in cells of both deposits while GPDH activity was elevated in inguinal vs epididymal derived stroma-vascular cells. The different adipose conversion pattern of both cultures was confirmed by morphological quantification: the maturation of epididymal fat cell precursors was faster but less extensive. These differences could be related mainly to regional localization rather than to different maturation of the two fat deposits.

Adipose Tissue↗
PubMed1985

Potential indicators of reproductive toxicity: testicular sperm production and epididymal sperm number, transit time, and motility in Fischer 344 rats.

Comprehensive assessment of the effects of chemicals on male reproductive functioning requires study of effects on spermatogenesis and the quality of spermatozoa produced. As potential indicators of toxic effects, we have examined sperm production rate (SPR) and epididymal sperm numbers, transit time, and motility (percentage motile cells and swimming speeds) in Fischer-344 (F-344) rats. Groups (n = 14 or 15) of rats at 6, 8, 10, 15, and 20 weeks of age were studied to investigate the suitability of these indicators for detecting toxic effects, and to establish the age at which this strain of rat sexually matures. Mean SPRs (10(6) sperm/rat/day), as measured by enumerating spermatids in testicular homogenates, were 2 +/- 3, 22 +/- 6, 41 +/- 7, 49 +/- 6, and 46 +/- 7 at 6, 8, 10, 15, and 20 weeks, respectively. Epididymal sperm numbers and the percentage of motile spermatozoa also increased with age. No correlation was found between SPR and either testis weight or epididymal sperm number at 10, 15, or 20 weeks of age. Our results indicate that male F-344 rats become sexually mature between 10 and 15 weeks of age, and that testis weight and epididymal sperm number are unreliable quantitative indicators of sperm production rate. The low variability among adult rats in SPR and some of the other indicators of testicular and epididymal functioning examined in this study suggest that they should be sensitive measures of male reproductive toxicity.

Age Factors↗