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PubMed1987

Time course of the tri-o-cresyl phosphate-induced testicular lesion in F-344 rats: enzymatic, hormonal, and sperm parameter studies.

Tri-o-cresyl phosphate (TOCP), a known neurotoxic compound, causes testicular toxicity in both leghorn roosters and Fischer 344 rats. The present study was initiated to follow the onset of the testicular lesion through possible changes in sperm numbers and production, serum hormones, and various enzyme activities. Rats were administered TOCP daily (150 mg/kg) for periods of 3, 7, 10, 14, or 21 days. Vehicle-treated animals served as controls. Sperm motility and sperm number per milligram cauda epididymis were both lower in treated animals by Day 10. Testicular weight to body weight ratio was significantly decreased only in the longest treatment duration animals (21 days). Testicular neurotoxic esterase and nonspecific esterase activities were also inhibited, while beta-glucuronidase activity was not affected. Luteinizing and follicle-stimulating hormone levels were normal, as were both serum and interstitial fluid testosterone concentrations. Sertoli cell fluid secretion, as measured by testis weight increase after efferent duct ligation, showed no significant changes. Other organs (spleen, liver, kidney, pancreas, small intestine, adrenal and pituitary glands) had no overt signs of pathology as observed by light microscopy in animals treated for 21 days. A separate group of animals was treated for 21 days and subsequently examined after 98 days of observation (two cycles of the rat seminiferous epithelium). No recovery of spermatogenesis was seen, indicating that the toxicity was irreversible at the dose used. The effects noted in these studies further define the testicular lesion produced by TOCP and show that 150 mg/kg/day for 21 days produced irreversible testicular toxicity.

Animals↗
PubMed1987

Influence of 12 hours of sound stimuli on gonad development and plasma luteinizing hormone in Japanese quail (Coturnix coturnix japonica) exposed to 6 hours of daily light.

Two experiments were conducted to determine the effects of sound stimulation on gonadal growth in male and female Japanese quail (Coturnix coturnix japonica) maintained under a photoperiod of 6 hr light and 18 hr dark (6L:18D) from 1 to 12 weeks of age (Experiment 1) or 1 to 14 weeks of age (Experiment 2). The quail were split into three sound environments as follows: 1) 12 hr of radio music (RS) beginning 1 hr before lights off; 2) 12 hr of vocalization from a breeding colony of quail (QV) beginning 1 hr before lights off; 3) no sound stimulation (NS). In Experiment 1, birds were killed at 8, 10, and 12 weeks of age and in Experiment 2, they were killed at 8, 10, 12, and 14 weeks of age. There were no significant differences in tests weights of the three groups at 8 and 10 wk of age (Experiment 1), but those of the RS and QV groups were larger (P less than or equal to .05) than those of the NS group at 12 weeks. Tests in the NS group appeared to grow between 8 and 10 weeks, then regress. There were no differences in testis weights at 8 and 10 weeks of age in Experiment 2. At 12 weeks, testes in the RS group were larger (P less than or equal to .05) than those of the other two groups and by 14 weeks testes of both sound stimulated groups were larger than the NS group and were also different from each other.(ABSTRACT TRUNCATED AT 250 WORDS)

Acoustic Stimulation↗
PubMed2003

Attributes of broiler breeder males characterized by low and high sperm mobility.

The attributes of broiler breeder males characterized by sperm mobility phenotype were studied in replicate experiments. Low and high phenotypes were observed in the first experiment over a 10-wk interval. Average straight line velocity differed between phenotypes (P < or = 0.05) as evidenced by computer-assisted sperm motion analysis. The second experiment compared low and high phenotypes from the same broiler breeder strain over a 29-wk interval. Body weight and fertility were measured in this experiment. Body weight data approximated parallel lines. The low phenotype averaged 227 g more than the high phenotype over the course of the experiment. Individual males were used as semen donors at 50, 54, 58, 62, and 65 wk of age. Eggs were collected for 2 wk after a single insemination at each age. Mean overall fertility (+/- SEM) was 44 +/- 4 and 69 +/- 2% for low and high sperm mobility phenotypes, respectively (P < or = 0.0001). As determined by transmission electron microscopy, the percentage of sperm with aberrant mitochondria was greater for the low sperm mobility phenotype (P < or = 0.0001). Neither blood plasma testosterone concentration nor testis weight differed between phenotypes. Sperm mobility is a biologically significant predictor of broiler breeder semen quality. The relationship between sperm mobility phenotype and body weight warrants further investigation.

Aging↗
PubMed1999

Hypophysectomy and/or peroxisome proliferators strongly influence the levels of phase II xenobiotic metabolizing enzymes in rat testis.

The objectives of the present work were to determine the influence of hypophysectomy and/or peroxisome proliferators (PP) on certain xenobiotic-metabolizing enzyme activities, i.e. glutathione transferases (GST), glutathione peroxidase (GPX), phenol sulphotransferases (pSULT), phenol UDP-glucuronosyl transferases (pUGT), catalase, NADP(H) quinone oxidoreductase (QR) and epoxide hydrolases (EH) in the rat testes. Adult male rats, hypophysectomized and their sham-operated controls, were treated for 10 days with clofibrate (0.5%), perfluorooctanoic acid (0.05%, PFOA), acetylsalicylic acid (1%, ASA) and di(2-ethylhexyl)phthalate (2%, DEHP) in their diet. The results show that, in addition to both body and testis weight, hypophysectomy caused dramatic changes in most of the xenobiotic-metabolizing enzyme activities, which have been measured here. The most pronounced effects were seen in cytosolic QR (2.2-fold increase), pUGT (95% reduction), pSULT (75% reduction), mitochondrial catalase (75% reduction), microsomal EH (70% reduction) and microsomal GST (55% reduction). Treatment with PP, i.e. perfluorooctanoic acid (PFOA), clofibrate, acetyl salicylic acid (ASA) and di(2-ethylhexyl)phthalate (DEHP) showed varied effects on the xenobiotic-metabolizing enzyme activities, the highest effects (10-60% reduction) were seen in sham-operated animals. These effects were not so pronounced or were not seen in hypophysectomized rats except for the case of PFOA treatment, which caused increases of enzyme activities. The highest increases were seen with microsomal GST (70%), GPX (75%) and cytosolic EH (75%). It is concluded from these experiments that the regulation of several xenobiotic-metabolizing enzymes in the rat testis is affected by the pituitary and/or pituitary hormones and that different peroxisome proliferators have variable effects on the levels of these xenobiotic-metabolizing enzymes. The general trend of reduction in enzyme activities implies that the testis is less protected under conditions that can perturb hormonal status.

Animals↗
PubMed1998

Male subfertility induced by acute scrotal heating affects embryo quality in normal female mice.

The aim of this experiment was to design a suitable mouse model for male subfertility in which to study the effect of decreased sperm quality on embryo quality in vivo and in vitro. To achieve male subfertility, testes of adult male mice were immersed in water at either 42 degrees C (heated) or 33 degrees C (controls) during 20 min. Twenty-eight days after treatment, all heat stressed males showed a significant decrease in relative testis weight [384.7 mg in controls (286.7-460.6) versus 323 mg in stress heated groups (117.9-405.6); P < 0.001], sperm concentration [3.75 x 10(6)/ml (2.75-7.25) versus 1.00 x 10(6)/ml (0-4.00); P < 0.001] and progressive sperm motility [57.5% (48.0-79.0) versus 42.5% (14.0-66.0); P < 0.001]. Moreover, after mating to heat exposed males, not only the number of pregnant females (20/22 versus 18/30) but also the weight of their embryos [275.4 mg (78.7-339.4) versus 261.8 mg (68.1-339.0); P < 0.001] was significantly lower at 14.5 days post coitum when compared to controls. Neither the number of resorption sites nor the number of viable embryos per pregnant female was significantly different between groups. Also, the in-vitro fertilization rate of oocytes, fertilized by spermatozoa collected from heat stressed males, was significantly lower (44.9%; P < 0.0001) when compared to controls (65.1%; P < 0.0001). In conclusion, the results of this study suggest that male subfertility induced by acute scrotal heating may result in impaired sperm quality, reduced embryo weight in vivo and decreased fertilization rate in vitro.

Animals↗
PubMed2002

Testis morphometry, seminiferous epithelium cycle length, and daily sperm production in domestic cats (Felis catus).

There is very little information regarding the testis structure and function in domestic cats, mainly data related to the cycle of seminiferous epithelium and sperm production. The testis weight in cats investigated in the present study was 1.2 g. Compared with most mammalian species investigated, the value of 0.08% found for testes mass related to the body mass (gonadosomatic index) in cats is very low. The tunica albuginea volume density (%) in these animals was relatively high and comprised about 19% of the testis. Seminiferous tubule and Leydig cell volume density (%) in cats were approximately 90% and 6%, respectively. The mean tubular diameter was 220 microm, and 23 m of seminiferous tubule were found per testis and per gram of testis. The frequencies of the eight stages of the cycle, characterized according to the tubular morphology system, were as follows: stage 1, 24.9%; stage 2, 12.9%; stage 3, 7.7%; stage 4, 17.6%; stage 5, 7.2%; stage 6, 11.9%; stage 7, 6.8%; and stage 8, 11 %. The premeiotic and postmeiotic stage frequency was 46% and 37%, respectively. The duration of each cycle of seminiferous epithelium was 10.4 days and the total duration of spermatogenesis based on 4.5 cycles was 46.8 days. The number of round spermatids for each pachytene primary spermatocytes (meiotic index) was 2.8, meaning that significant cell loss (30%) occurred during the two meiotic divisions. The total number of germ cells and the number of round spermatids per each Sertoli cell nucleolus at stage 1 of the cycle were 9.8 and 5.1, respectively. The Leydig cell volume was approximately 2000 microm3 and the nucleus volume 260 microm3. Both Leydig and Sertoli cell numbers per gram of testis in cats were approximately 30 million. The daily sperm production per gram of testis in cats (efficiency of spermatogenesis) was approximately 16 million. To our knowledge, this is the first investigation to perform a more detailed and comprehensive study of the testis structure and function in domestic cats. Also, this is the first report in the literature showing Sertoli and Leydig cell number per gram of testis and the daily sperm production in any kind of feline species. In this regard, besides providing a background for comparative studies with other fields, the data obtained in the present work might be useful in future studies in which the domestic cat could be utilized as an appropriate receptor model for preservation of genetic stock from rare or endangered wild felines using the germ cell transplantation technique.

Animals↗
PubMed2001

Essential role of neutrophils in germ cell-specific apoptosis following ischemia/reperfusion injury of the mouse testis.

This study investigates the role of neutrophils in ischemia-induced aspermatogenesis in the mouse. Previous studies in the rat have demonstrated that ischemia-inducing testicular torsion followed by torsion repair and reperfusion resulted in germ cell-specific apoptosis. This was correlated with an increase in neutrophil adhesion to subtunical venules, an increase in reactive oxygen species, and increased expression of several apoptosis-associated molecules. In the present investigation, wild-type C57BL/6 mice were subjected to various degrees and duration of testicular torsion. A torsion of 720 degrees for 2 h caused disruption of the seminiferous epithelium and significantly reduced testis weight and daily sperm production. An immunohistochemical method specific for apoptotic nuclei indicated that these effects were due to germ cell-specific apoptosis. An increase in myeloperoxidase (MPO) activity and an increase in the number of neutrophils adhering to testicular subtunical venules after torsion repair/reperfusion demonstrated an increase in neutrophil recruitment to the testis. In contrast, E-selectin knockout mice and wild-type mice rendered neutropenic showed a significant decrease in neutrophil recruitment as evidenced by MPO activity and microscopic examination of subtunical venules. Importantly, germ cell-specific apoptosis was also reduced. Thus, germ cell-specific apoptosis is observed after ischemia/reperfusion of the murine testis, and this apoptosis is directly linked to the recruitment of neutrophils to subtunical venules. Endothelial cell adhesion molecules, particularly E-selectin, play an important role in mediating this pathology.

Animals↗
PubMedDate not supplied

[Relative biological effectiveness of tritium oxide by the criterion of death of the germ cells in mice].

It was shown that low-level beta-radiation of tritium is much more effective than gamma-radiation of 137Cs with respect to reduction of the mouse testis weight. The RBE coefficient increases from 1.8 at a dose of 1 Gy to 2.2-2.3 at 0.1 Gy. On the basis of the data obtained by the authors and those reported in the literature a quality factor is proposed for tritium: QF = 2. Using THO and Na36Cl labels a mean water content of the testis cells, necessary for the estimation of a tritium-radiation dose absorbed, has been determined: gamma ct = 0.70 +/- 0.02 ml/g.

Animals↗
PubMed1995

Radiosensitivity of testicular cells in the fetal mouse.

The effects of prenatal X irradiation on postnatal development of the CBA/P mouse testis was studied. At days 14, 15 and 18 post coitus pregnant female mice were exposed to single doses of X rays ranging from 0.25-1.5 Gy. Higher doses resulted in extensive loss of fetal mice. In the male offspring, at days 3 and 31 post partum, the numbers of gonocytes, type A spermatogonia and Sertoli cells per testis were determined using the disector method. Furthermore, after irradiation at day 15 post coitus, the numbers of Leydig cells, mesenchymal cells, macrophages, myoid cells, lymphatic endothelial cells, endothelial cells and perivascular cells per testis were also determined at days 3 and 31 post partum. At day 3 post partum, the number of germ cells was decreased after irradiation at days 14 and 15 post coitus. A D0 value of 0.7 Gy was determined for the radiosensitivity of the gonocytes at day 14 post coitus. A D0 value of 0.8 Gy was determined for the gonocytes at day 15 post coitus which, however, seems to be less accurate. No accurate D0 value could be determined for the gonocytes at day 18 post coitus. At day 31 post partum, the repopulation of the seminiferous epithelium as well as testis weights and tubular diameters were more affected by irradiation with increasing age of the mice at the time of irradiation. The percentage of tubular cross sections showing spermatids decreased with increasing dose after irradiation at days 15 and 18 post coitus, but not after irradiation at day 14 post coitus. Furthermore, in tubular cross sections showing spermatids, exposure of testes to 1.25 and 1.5 Gy at day 18 post coitus resulted in significantly lower numbers of spermatids per cross section when compared to those testes exposed to the same doses at day 15 post coitus. This indicates that the radiosensitivity of the gonocytes increases with fetal age. Prenatal irradiation did not cause significant changes in the numbers per testis of the Sertoli cells or the interstitial cell types. The present results indicate that, in the fetal mouse testis, the spermatogonial stem cells are more sensitive to X irradiation than in the adult testis, while Sertoli cells and interstitial cells are relatively resistant.

Aging↗
PubMed2005

High doses of nandrolone decanoate reduce volume of testis and length of seminiferous tubules in rats.

Anabolic-androgenic steroid (AAS) compounds rank among the drugs most widely abused with the goal of improving athletic ability, appearance, or muscle mass. It has been shown that these compounds have adverse effects on human and animal physiology and sperm quality, but quantitative structural changes of the testis have received less attention. The present study was conducted to evaluate the effects of nandrolone decanoate, which is one of the AAS compounds, on testis weight and volume, diameter and length of seminiferous tubules in rats by unbiased stereological methods. Adult rats were divided into three groups. The first comprised control rats; the second and third groups received low and high doses of nandrolone decanoate for 14 weeks. The rats were then left untreated for 14 weeks. After removal of the testis, stereological study of these tissues showed that the mean volume of testis and length of the seminiferous tubules in the animals that received high doses of nandrolone decanoate were reduced approximately 32% (p<0.01) and approximately 31% (p<0.04), respectively, in comparison with the control group. It can be concluded that the high doses of nandrolone decanoate produce structural changes in the rat testis that remain 14 weeks after stopping injection of the drug.

Anabolic Agents↗
PubMed1986

Semen quality and fat accumulation in prepuberal and postpuberal male turkeys as affected by restricted feeding.

Growth, semen production, and carcass fat distribution were examined in adult male turkeys subjected to feed restriction from 10 to 46 weeks of age. Turkeys were randomly assigned to one of three feeding treatments: control (ad libitum) or restricted-fed to maintain body weight at 80% (80R) or 60% (60R) of the control toms. Feed consumption for the 80R and 60R males was decreased significantly by 27.3 and 50.9%, respectively, when compared with the control males during the 10 to 46-week production period. Feed restriction resulted in a 2-week delay in semen production as evidenced by reduced testis weights and reduced semen volume at 34 weeks of age. Semen production was not affected by feed restriction at 36 or 42 weeks of age. A major change in fat accumulation was found after exposure to a stimulatory lighting regimen. The change was from a uniform weight distribution among the fat stored in the abdominal, clavicular, and back at 28 weeks to a major increase in the clavicular fat depot at 34 weeks of age. Total fat accumulation was decreased significantly by feed restriction of turkey males.

Adipose Tissue↗
PubMed2003

Assessment of reproductive and fertility effects of amitraz pesticide in male mice.

Forty adult male Swiss mice were exposed to tap water containing 0, 40, 80, or 160 ppm amitraz for 12 weeks. Based on fluid consumption the mice received an average of 0, 5.42+/-0.47, 10.56+/-0.97, and 20.39+/-2.17 mg/kg/day amitraz, respectively. The average body weights gains and fluid consumption were significantly decreased in males exposed to amitraz pesticide. Fertility was significantly reduced in male mice ingesting 10.56+/-0.97 or 20.39+/-2.17 mg/kg/day amitraz in that the number of females impregnated by them was significantly reduced. The number of viable fetuses was significantly reduced in females mated with males that ingested 10.56+/-0.97 or 20.39+/-2.17 mg/kg/day amitraz. A significant increase in the total number of resorptions and the number of females with resorptions was observed in females impregnated with the exposed males. Absolute testis weight was significantly decreased at 10.56+/-0.97 mg/kg concentration. The weight of the epididymis was decreased in test males ingested 20.39+/-2.17 mg/kg amitraz. The seminal vesicles weights were significantly increased in male mice ingested 10.56+/-0.97 or 20.39+/-2.17 mg/kg/day amitraz. Similarly, the preputial gland weights were increased in males that ingested 5.42+/-0.47 or 10.56+/-0.97 mg/kg and decreased in males ingested 20.39+/-2.17 mg/kg amitraz. Testicular sperm counts and daily sperm production were significantly decreased in males that ingested 10.56+/-0.97 or 20.39+/-2.17 mg/kg/day amitraz. Epididymal sperm counts were significantly decreased in exposed male's at 10.56+/-0.97 or 20.39+/-2.17 mg/kg amitraz. These results strongly suggest that exposure to amitraz pesticide have an adverse effect on the fertility and reproductive system of male mice.

Animals↗
PubMed1987

The influence of vasovasostomy on testicular alterations after vasectomy in Lewis rats.

The occurrence of alterations in testicular weight and morphology after vasectomy and vasectomy reversal by vasovasostomy was studied in Lewis rats. Animals were studied 3, 4, and 7 months after bilateral vasectomy or a vasectomy followed 3 months later by vasovasostomy. Other rats served as sham-operated controls. The weights of the testes in vasectomy and vasovasostomy animals fell into two groups-small testes weighing less than 0.88 g and normal-sized testes of 1.2 g or more. When the extent of testicular alterations was estimated in sections for light microscopy by use of a semiquantitative testicular biopsy score count (TBSC), the morphology of the testes corresponded closely to the testis weight (r = .94), small testes having correspondingly low TBSC scores. In severely altered small testes, the seminiferous tubules were narrower than in sham-operated rats, and numbers of germ cells were greatly depleted. Many tubules contained only Sertoli cells and spermatogonia, although spermatocytes were present in a minority of tubules. A few seminiferous tubules contained multinucleate spermatids. Electron microscopy of severely altered tubules revealed closely apposed processes of Sertoli cells, which contained filaments, microtubules, and endoplasmic reticulum. In contrast, testes with normal weight in vasectomy and vasovasostomy groups resembled those of the sham-operated animals. Comparison of distributions of testicular biopsy score counts demonstrated differences between vasectomy and vasovasostomy groups as time after operation increased. At the 3-4-month intervals, approximately one-third of the testes were severely altered in both vasectomy and vasovasostomy groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMedDate not supplied

Changes in vascular dynamics of the adult rat testis leading to transient accumulation of seminiferous tubule fluid after administration of a novel 5-hydroxytryptamine (5-HT) agonist.

The aim of the present study was to evaluate the possible mechanisms of testicular toxicity of GR40370X, a follow-up 5-hydroxytryptamine (5-HT) receptor agonist. Administration to adult male rats of a single (toxic) dose of 750 mg/kg GR40370X induced marked distension of seminiferous tubules and an associated increase in testis weight at 12-24 h with a gradual recovery to normal by 96 h. Seminiferous tubule distension was due to expansion of the lumen, which occurred at all stages of the spermatogenic cycle and was accompanied by vacuolation of the cytoplasm of elongating spermatids. Seminiferous tubule distension was preceded/accompanied by distension of the efferent ducts and rete testis with maximal changes evident at 24-48 h. These changes could not be explained by increases in seminiferous tubule fluid or interstitial fluid production, as both were reduced (15-20%), rather than increased, by treatment. Examination of the vasculature after treatment with 750 mg/kg GR40370X revealed significant changes that were maximal at 4 h and thus preceded rete/testicular changes. Veins of the mediastinal venous plexus, which overlies the rete, were constricted and arteriovenous anastomoses in the spermatic cord were shut/constricted, as determined (indirectly) by measurement of the dilution of outflowing testicular venous blood by incoming arterial blood. The latter effect of GR40370X could be blocked by co-administration of minoxidil, a vasodilator. Vascular effects of GR40370X had normalised by 24-48 h. It was also noted that administration of a toxic dose of GR40370X significantly lowered blood levels of LH and testosterone, though these changes were considered to be incidental and not involved in the other changes described above. None of the above changes were induced by a pharmacologically active dose (1 mg/kg) of GR40370X. It is concluded that the mechanism of testicular toxicity induced by 750 mg/kg GR40370X results from primary effects on the vasculature of the testis/neighbouring region, which in turn lead to impaired fluid resorption from the efferent ducts and rete and thence to accumulation of seminiferous tubule fluid in the rete and testis.

Animals↗
PubMed2003

Aggressive behavior and serum testosterone concentration during the maturation process of male mice: the effects of fetal exposure to bisphenol A.

The relationship between exposure to endocrine-disrupting chemicals (EDs) and risk to reproductive organs is well documented, but the influence of EDs on behavioral development has not been studied. In this study we evaluated the effect of fetal exposure to bisphenol A, which mimics estrogenic activity, on aggressive behavior and hormonal change in male mice. On gestation days 11-17, female mice were fed bisphenol A at 2 ng/g or 20 ng/g of body weight (environmentally relevant concentration). Aggression rating and blood sampling of the offspring were done at 8, 12, and 16 weeks of age. Aggression scores increased significantly (p < 0.01) at 8 weeks of age in male mice exposed to bisphenol A at both the 2 ng/g and 20 ng/g concentrations compared with a control group, but no difference was found after 12 weeks. Relative testis weight (per gram of body weight) was significantly lower at 8 and 12 weeks in mice treated with 2 ng/g than in controls (p < 0.05) and was significantly lower at 12 weeks in mice treated with 20 ng/g than in controls (p < 0.01). The serum testosterone concentration in treated mice was not significantly different from that in controls. These results demonstrate that bisphenol A temporarily activated aggressive behavior in mice at 8 weeks of age and that low doses of bisphenol A interfered with the normal development of reproductive organs. The mechanism activating this aggressive behavior was not elevated testosterone concentration.

Administration, Oral↗
PubMed1987

Enhancement of testicular cysteine proteinase inhibitor level in vitamin E-deficient rats.

The effect of vitamin E deficiency on levels of proteinase inhibitors in sex glands of male rats was studied. Inhibitor levels against cysteine proteinases, such as ficin and cathepsin H, and against serine proteinase such as trypsin were examined. Vitamin E deficiency for 4 mo after weaning induced a fivefold increase in cysteine proteinase inhibitor level in testis, a two- to fourfold increase in prostate and epididymis and no change in seminal vesicle. No appreciable change was observed in trypsin inhibitor level in testis, epididymis or seminal vesicle. Therefore, vitamin E deficiency was reflected most sensitively by the cysteine proteinase inhibitor level in testis. These observations agree with our previous findings that alpha-cysteine proteinase inhibitors in serum increased greatly whereas trypsin inhibitor in serum did not change in vitamin E-deficient rats. Major histological changes were observed in the testes of rats fed a vitamin E-deficient diet for 4 mo, although testis weight was not significantly affected by vitamin E deficiency.

Animals↗
PubMed2005

Testicular development of Zebu bulls after chronic treatment with a gonadotropin-releasing hormone agonist.

The objective was to compare testis characteristics of Zebu bulls treated with the GnRH agonist, deslorelin, at different times and for different durations during their development. An additional objective was to determine the usefulness of a stain for the transcription factor GATA-binding protein 4 (GATA-4) as a specific marker for Sertoli cell nuclei in cattle. Bulls (54) were allocated to nine groups (n = 6) and received s.c. deslorelin implants as follows: G1 = from birth to 3 mo of age; G2 = from 3 to 6 mo; G3 = from 6 to 9 mo; G4 = from 9 to 12 mo; G5 = from birth to 15 mo; G6 = from 3 to 15 mo; G7 = from 6 to 15 mo; G8 = from 12 to 15 mo; and G9 (control) = no implant. Bulls were castrated at 19 mo of age. Paraffin sections (10 microm) were subjected to quantitative morphometry and GATA-4 immunohistochemistry. At castration, all bulls in the control group (6/6) had attained puberty (scrotal circumference > or = 28 cm), whereas a smaller proportion (P < 0.05) had reached puberty in G2 (2/5) and G6 (1/6). Bulls in G2 and G6 also had a lesser (P < 0.05) testis weight compared with the control group. Total volume of seminiferous epithelium and total daily sperm production in G2 and G6 were only half that observed in the control group. Spermatids were observed in less than 50% of seminiferous tubules in G2, G6, and G7 compared with 82% in the control group (P < 0.05). Staining for GATA-4 was specific for and abundant in the Sertoli cell nucleus in both pre- and postpubertal bulls, and no other cell nucleus inside the seminiferous tubule was positive for GATA-4. Total number of Sertoli cells was not affected by treatment (P = 0.45), but nuclear volume was smaller in G2 and G6 (P < 0.05) compared with the control group. In conclusion, treatment of Zebu bulls with deslorelin had no apparent beneficial effect on testis development and delayed puberty when treatment was initiated at 3 mo of age. Staining for GATA-4 was a useful method for identifying and quantifying Sertoli cell nuclei in both pre- and postpubertal bulls.

Animals↗
PubMed1990

Regulation of the testicular activity in the marine teleost fish, Gobius paganellus.

Seasonal variations of intratesticular steroid hormones (androgens and estradiol-17 beta) and spermatogenic activity have been studied in the marine teleost fish, Gobius paganellus. In addition, in vivo and in vitro experiments have been carried out in order to investigate the control of androgen production by the testis. While estradiol was never detected, androgens were at low values in autumn and reached maximal levels in spring concomitantly with the highest testis weight and the highest efficiency of the spermatogenic wave. In vitro incubations were carried out using ovine luteinizing hormone (oLH) (400, 4000, and 40,000 micrograms/liter; 20 degrees for 6 and 24 hr). The effective dose 40,000 micrograms/liter was used to induce androgen stimulation in both autumn and spring testes. The responsiveness to oLH was enhanced in spring testis. Estradiol and a gonadotropin-releasing hormone analog GnRHA (HOE766) were ineffective in modulating androgen production either alone (1-1000 nmol/liter) or in concert with oLH during short-term incubations. In intact animals, GnRHA elicited, 3 hr after the injection (10 micrograms), a three-fold increase of intratesticular androgen content. In conclusion, we show that the annual androgen profile in G. paganellus parallels the spermatogenic activity and that the androgen production is not affected in these experimental conditions by putative intratesticular factors (e.g., estradiol-17 beta and GnRH-like substances) which, conversely, are effective in inducing androgen changes in several vertebrate species.

Androgens↗