Prepubertal treatment of rats with clomiphene citrate affects postpubertal testicular development

1989 ◽  
Vol 120 (4) ◽  
pp. 423-428 ◽  
Author(s):  
Janine L. Brown ◽  
Prabir K. Chakraborty
Keyword(s):  
Cell Function ◽  
Clomiphene Citrate ◽  
Serum Testosterone ◽  
Normal Serum ◽  
Gnrh Receptor ◽  
Testicular Development ◽  
Fsh Receptor ◽  
Sperm Production ◽  
Testicular Weight ◽  
Daily Sperm Production

Abstract. A previous study showed that clomiphene citrate (clomiphene) reduced serum and pituitary gonadotropins and impaired testis growth and steroidogenesis in 10-day-old rats treated for up to two weeks. The present study was conducted to assess the effect of prepubertal clomiphene treatment on postpubertal pituitary-testicular function. Rats were implanted with pellets that released 0, 0.05, 0.5 or 5.0 mg clomiphene ·kg−1·day−1 between 10–31 days of age and were killed at 90 days of age. Testis and prostate weights in treated rats were reduced (P< 0.05), whereas serum LH, FSH and testosterone, and pituitary gonadotropin and GnRH receptor concentrations had recovered to levels observed in control rats. Testicular FSH receptor concentrations were not altered; however, FSH receptor content was decreased (P< 0.05) in clomiphene-treated rats proportional to the reduction in testicular weight. In contrast, testicular LH and GnRH receptor concentrations were increased (P< 0.05) in treated animals, resulting in similar receptor contents. Daily sperm production per gram of parenchyma was unaffected, while daily sperm production per testis was decreased in treated rats (P< 0.05). These data show early postnatal treatment with clomiphene does not permanently impair pituitary function. Despite reduced testicular mass, normal serum testosterone concentrations and testis LH receptor content of treated rats suggest recovered Leydig cell function. The decreased content of testicular FSH receptors and reduced sperm production suggest seminiferous tubule function was compromised in the adult rat.

Initiation of spermatogenesis and testicular growth in oestradiol-17β-implanted bull calves with pulsatile infusion of luteinizing hormone releasing hormone

1982 ◽  
Vol 93 (2) ◽  
pp. 183-NP ◽  
Author(s):  
B. D. Schanbacher ◽  
M. J. D'Occhio ◽  
J. E. Kinder
Keyword(s):  
Pubertal Development ◽  
Serum Testosterone ◽  
Sperm Production ◽  
Releasing Hormone ◽  
Testicular Growth ◽  
Bull Calves ◽  
Testicular Weight ◽  
Additional Support ◽  
Lh Rh ◽  
Lh Releasing Hormone

Testicular growth and secretory profiles of LH and testosterone were monitored in three bull calves implanted with oestradiol-17β and three bull calves implanted with oestradiol-17β and infused intravenously with LH releasing hormone (LH-RH; 500 ng/pulse per h, 30-s pulse) continuously between 34 and 42 weeks of age. Oestradiol-17β implants restricted testicular growth and spermatogenesis by interfering with the hypothalamo-pituitary-testicular endocrine axis. Initiation of pulsatile LH release by LH-RH pulse infusion was accompanied by a twofold increase in mean circulating levels of LH (3·4 v. 1·8 μg/l) and a marked increase in serum testosterone (13·0 v. 0·4 μg/l). Testicular diameter was enhanced significantly by week 4 of infusion and increased in a linear fashion up to and including week 8. Testicular weight (g) and total daily sperm production (× 109) at 42 weeks of age were decreased in calves implanted with oestradiol-17β (105 ± 14 (s.e.m.); 0·0) when compared with calves implanted with oestradiol-17β and infused with LH-RH (254 ± 12; 1·2 ± 0·3). Differences in testicular size and sperm production rates between LH-RH-infused and control bulls without implants (352 ± 26; 3·3 ± 0·9) were attributed to the 2-month delay between oestradiol-17β treatment and the initiation of LH-RH treatment. These results (1) confirm our earlier conclusion that oestradiol-17β can interfere with normal pubertal development in beef bulls and (2) provide additional support that pulsatile LH secretion is important for the initiation of testicular growth and spermatogenesis in pubertal bulls.

Sexual maturation of the Mongolian gerbil (Meriones unguiculatus): a histological, hormonal and spermatic evaluation

2016 ◽  
Vol 28 (6) ◽  
pp. 815 ◽  
Author(s):  
Maria Etelvina Pinto-Fochi ◽  
Ana Carolina Negrin ◽  
Wellerson Rodrigo Scarano ◽  
Sebastião Roberto Taboga ◽  
Rejane Maira Góes
Keyword(s):  
Mongolian Gerbil ◽  
Leydig Cells ◽  
Serum Testosterone ◽  
Meriones Unguiculatus ◽  
Sperm Production ◽  
Mature Adult ◽  
Drastic Increase ◽  
Testicular Morphology ◽  
Sexually Mature ◽  
Daily Sperm Production

This study determined the phases of sexual development of the male Mongolian gerbil (Meriones unguiculatus) based on an integrative analysis of testicular morphology, hormonal data and sperm parameters. Male gerbils were analysed at 1, 7, 14, 21, 28, 35, 42, 50, 60, 70, 90, 100 and 120 days of age. Body, testicular and epididymal weights increased up to Day 70, 60 and 90, respectively. The impuberal phase, characterised by the presence of gonocytes, extended until Day 14. The prepubertal period lasted until Day 42, when puberty was achieved and a drastic increase in serum testosterone levels, mature adult Leydig cells and elongated spermatids was observed. Gerbils at 60 days of age showed a remarkable number of spermatozoa in the testis, epididymidis caput/corpus and cauda, and at Day 70 the maximum daily sperm production was reached. However, the gerbil may be considered sexually mature only from Day 90 onward, when sperm reserves become stable. The total transit time of spermatozoa along the epididymis of sexually mature gerbils was 11 days, with 1 day in the caput/corpus and 10 days in the cauda. These data cover a lacuna regarding the reproductive parameters of this rodent and provide foundations for its use in testicular toxicology studies.

scholarly journals Changes in endocrine profile and reproductive organs during puberty in the male marmoset monkey (Callithrix jacchus)

Reproduction ◽  
2006 ◽  
Vol 132 (2) ◽  
pp. 355-363 ◽  
Author(s):  
Ramesh K Chandolia ◽  
Craig Marc Luetjens ◽  
Joachim Wistuba ◽  
Ching-Hei Yeung ◽  
Eberhard Nieschlag ◽  
...  
Keyword(s):  
Age Groups ◽  
Serum Testosterone ◽  
Serum Levels ◽  
Reproductive Organs ◽  
Human Reproduction ◽  
Testicular Development ◽  
Marmoset Monkey ◽  
Age Related ◽  
Testicular Weight ◽  
Endocrine Profile

Data on pubertal maturation in male marmoset, a model for human reproduction, are scant and conflicting. We collected data on novel parameters to characterize puberty. Twenty-five marmoset monkeys were assigned to five age groups by weeks (wk): 21 (pre-pubertal), 43 (onset of puberty), 52 (fully pubertal), 70 (mature), and 116 (fully adult). Serum and intratesticular testosterone and pituitary bioactive chorionic gonadotropin (bioCG) were measured. Testicular development was assessed by ultrasonography, histology, and flow cytometry. Three consecutive blood samples revealed extreme fluctuations in testosterone concentrations, suggesting an erratic secretion. Age-related changes in serum testosterone and pituitary bioCG concentrations were observed. Intratesticular androgens (ITAs) showed high fluctuations within groups at all ages and were high in some animals by 21 wk. Unexpectedly, no correlation between pituitary bioCG and serum testosterone or ITAs was found, but these parameters significantly correlated with testicular weight and volume. These observations were consistent a dependence on the testis growth on bioCG. Unfortunately, the low serum levels of bioCG were not measurable in this study. At 43 wk, the animals reached puberty. At 52 wk of age, animals attained maximum body and epididymal weights and qualitatively normal spermatogenesis, but testes continued growing, reaching a maximum of all parameters at 70 wk of age, without further major changes at the age of 116 wk. It is concluded that (1) gonadal activation is evident at wk 21, (2) the male marmoset reaches the pubertal threshold around 43 wk of age, attains qualitative parameters at 52 wk, matures further to sexual maturity at 70 wk, and (3) serum testosterone and ITAs are highly variable without any identifiable correlation with pituitary bioCG.

Testicular and epididymal sperm content in grazing Cashmere bucks: seasonal variation and prediction from measurements in vivo

1994 ◽  
Vol 6 (6) ◽  
pp. 727 ◽  
Author(s):  
SW Walkden-Brown ◽  
BJ Restall ◽  
WA Taylor
Keyword(s):  
Seasonal Variation ◽  
Seasonal Pattern ◽  
Sperm Production ◽  
Epididymal Sperm ◽  
Scrotal Circumference ◽  
Indirect Measures ◽  
Significant Seasonal Variation ◽  
Testicular Weight ◽  
Daily Sperm Production

Each month, for 15 months, the testes and epididymides were recovered from five Australian cashmere bucks selected at random from a group of mature bucks (initial n = 116) at pasture (location 29 degrees S, 153 degrees E). The extent of seasonal change in testicular and epididymal sperm reserves was determined and indirect methods for predicting these reserves were developed. Paired testicular weight exhibited clear seasonal variation from 137 g in August to 269 g in February. The total elongated spermatid content of the testes, determined by homogenization, showed a very similar seasonal pattern, ranging from 13.8 x 10(9) in September to 36.2 x 10(9) in March. Seasonal changes of similar timing were observed for paired epididymal weight and sperm content. Although changes in total testicular spermatid content were largely the result of change in testicular weight (R2 = 0.72, P < 0.001), the elongated spermatid content of testicular parenchyma (mean, 127 x 10(6) g-1) exhibited significant seasonal variation with elevated values between February and June, suggestive of an increase in the efficiency of spermatogenesis. Daily sperm production, calculated by means of a spermatogenic time divisor for sheep, ranged from 2.76 x 10(9) in September to 7.23 x 10(9) in February. Scrotal circumference, scrotal volume and testicular length x diameter2 were identified as accurate predictors of testicular weight (R2 > or = 0.87) and sperm content (R2 > or = 0.70). The results demonstrate that: (a) cashmere bucks exhibit considerable seasonal variation in spermatogenesis associated primarily with changes in testicular mass but also with changes in the efficiency of spermatogenesis; and (b) indirect measures of testicular size are good predictors of testicular elongated sperm content. When the correct spermatogenic time divisor for goats is determined, such indirect measures may be used to predict daily sperm production.

Pituitary–testicular interrelationships during germinal involution in the vitamin A deficient rat

1984 ◽  
Vol 100 (1) ◽  
pp. 33-41 ◽  
Author(s):  
H. F. S. Huang ◽  
P. Zaidi ◽  
E. Nieschlag
Keyword(s):  
Vitamin A ◽  
Vitamin A Deficiency ◽  
Serum Testosterone ◽  
Normal Serum ◽  
Male Rats ◽  
Total Testosterone ◽  
Cell Nuclei ◽  
Serum Lh ◽  
Testicular Weight ◽  
Lh Secretion

ABSTRACT Pituitary–testicular relationships in mature male rats were investigated during the period of germinal involution after the induction of vitamin A deficiency (VAD). Vitamin A deficiency caused a decrease in testicular weight, a gradual increase in the incidence of delayed spermiation, increased phagocytosis of spermatids and pyknosis of germ cell nuclei in rats aged 80 to 110 days. Both basal and gonadotrophin releasing hormone (GnRH)-stimulated serum FSH concentrations were increased by 100 days of age. During the same period, the per cent increment in GnRH-stimulated FSH secretion, pituitary FSH concentration and LH secretion remained unchanged. These results suggest that the increased serum FSH may mark specifically an alteration in the germinal epithelium. By 140 days of age, spermatogenic activity in the rats with VAD was limited to the spermatogonial proliferations so that only Sertoli cells, spermatogonia and preleptotene spermatocytes remained. At this time hypersecretion of FSH persisted while the per cent increment of GnRH-stimulated FSH secretion decreased. Concomitantly, basal and GnRH-stimulated LH concentrations were also increased in the presence of normal serum testosterone. These results indicate that a complete cessation of spermatogenesis beyond preleptotene spermatocytes is associated with a change in the secretion of both FSH and LH. The relationship between serum LH and testosterone was normal until at least 110 days of age. By 140 days the ratio between basal LH and basal testosterone, and between total LH and total testosterone, after GnRH administration, increased in the rats with VAD. These changes may be caused by a hyporesponsiveness of the Leydig cells which may, in turn, be attributed to the cessation of spermatogenesis. J. Endocr. (1984) 100, 33–41

scholarly journals Testicular parameters and spermatogenesis in different birthweight boars

2017 ◽  
Vol 29 (9) ◽  
pp. 1720 ◽  
Author(s):  
P. A. Auler ◽  
G. H. F. A. Moreira ◽  
C. O. Hogg ◽  
C. J. Ashworth ◽  
F. P. Bortolozzo ◽  
...  
Keyword(s):  
Germ Cell ◽  
The Other ◽  
Testicular Development ◽  
Sperm Production ◽  
Relative Expression ◽  
Cell Numbers ◽  
Pachytene Spermatocytes ◽  
Neonatal Testis ◽  
Daily Sperm Production

The present study investigated the effect of birthweight on testicular development and spermatogenesis in boars. Twenty-four pairs of littermate boars were selected: one piglet with the highest birthweight (HW) and the other with the lowest birthweight (LW) within the litter. Two subsets of 12 pairs of male littermates from each birthweight group were obtained after selection: one subset was orchiectomised at 8 days and the other at 8 months of age. HW boars had higher body and testicular weights at both ages (P < 0.05). Testosterone concentrations and the relative expression of 17α-hydroxylase in the testis were similar between birthweight groups. Birthweight affected somatic and germ cell numbers in the neonatal testis, which were higher in HW boars (P < 0.05). Moreover, a significant reduction in the number of pachytene spermatocytes and round spermatids was observed in LW boars (P < 0.05) at 8 months of age, which caused a decrease in the total number of elongated spermatids and daily sperm production (P < 0.05). Hence, HW boars have the potential to produce more spermatozoa and consequently more semen doses per ejaculate, and would be very valuable to an industry that relies on AI.

scholarly journals Enhanced Sexual Behaviors and Androgen Receptor Immunoreactivity in the Male Progesterone Receptor Knockout Mouse

Endocrinology ◽  
2005 ◽  
Vol 146 (10) ◽  
pp. 4340-4348 ◽  
Author(s):  
Johanna S. Schneider ◽  
Carly Burgess ◽  
Nicole C. Sleiter ◽  
Lydia L. DonCarlos ◽  
John P. Lydon ◽  
...  
Keyword(s):  
Sexual Behavior ◽  
Androgen Receptor ◽  
Progesterone Receptor ◽  
Sexual Behaviors ◽  
Gene Deletion ◽  
Biological Significance ◽  
Receptor Expression ◽  
Androgen Receptor Expression ◽  
Testicular Development ◽  
Testicular Weight

Reproductive and behavioral functions of progesterone receptors (PRs) in males were assessed by examining consequences of PR gene deletion. Basal hormone levels were measured in male progesterone receptor knockout (PRKO) mice and compared to wild-type (WT) counterparts. RIA of serum LH, testosterone, and progesterone levels revealed no significant differences. Levels of FSH were moderately but significantly lower and inhibin levels were higher in PRKOs; these differences were not accompanied by gross differences in testicular weight or morphology. PRKOs exhibited significant alterations in sexual behavior. In initial tests PRKOs exhibited reduced latency to mount, compared with WT. In second sessions, PRKOs again showed a significantly reduced latency to mount and increased likelihood of achieving ejaculation. RU486 treatment in WT produced increased mount and intromission frequency and decreased latency to intromission. In anxiety-related behavior tests, PRKO mice exhibited intermediate anxiety levels, compared with WT, suggesting that enhanced sexual behavior in PRKOs is not secondary to reduced anxiety. Immunohistochemical analysis revealed significantly enhanced androgen receptor expression in the medial preoptic nucleus and bed nucleus of the stria terminalis of PRKO. We conclude that testicular development and function and homeostatic regulation of the hypothalamic-pituitary testicular axis are altered to a lesser extent by PR gene deletion. In contrast, PR appears to play a substantial role in inhibiting the anticipatory/motivational components of male sexual behavior in the mouse. The biological significance of this inhibitory mechanism and the extent to which it is mediated by reduced androgen receptor expression remain to be clarified.

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