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 ◽  
...  

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.

Reproduction ◽  
2005 ◽  
Vol 130 (6) ◽  
pp. 923-929 ◽  
Author(s):  
Rahul Rathi ◽  
Ali Honaramooz ◽  
Wenxian Zeng ◽  
Stefan Schlatt ◽  
Ina Dobrinski

Spermatogenesis can occur in testis tissue from immature bulls ectopically grafted into mouse hosts; however, efficiency of sperm production is lower than in other donor species. To elucidate a possible mechanism for the impaired spermatogenesis in bovine testis xenografts, germ cell fate and xenograft development were investigated at different time points and compared with testis tissue from age-matched calves as controls. Histologically, an initial decrease in germ cell number was noticed in xenografts recovered up to 2 months post-grafting without an increase in germ cell apoptosis. From 2 months onward, the number of germ cells increased. In contrast, a continuous increase in germ cell number was seen in control tissue. Pachytene spermatocytes were observed in some grafts before 4 months, whereas in the control tissue they were not present until 5 months of age. Beyond 4 months post-grafting spermatogenesis appeared to be arrested at the pachytene spermatocyte stage in most grafts. Elongated spermatids were observed between 6 and 8 months post-grafting, similar to the controls, albeit in much lower numbers. Lumen formation started earlier in grafts compared with controls and by 6 months post-grafting tubules with extensively dilated lumen were observed. A donor effect on efficiency of spermatogenesis was also observed. These results indicate that the low efficiency of sperm production in bovine xenografts is due to an initial deficit of germ cells and impaired meiotic and post-meiotic differentiation. The characterization of spermatogenic efficiency will provide the basis to understand the control of spermatogenesis in testis grafts.


1989 ◽  
Vol 123 (3) ◽  
pp. 403-NP ◽  
Author(s):  
J. M. S. Bartlett ◽  
G. F. Weinbauer ◽  
E. Nieschlag

ABSTRACT Synchronization of spermatogenesis would provide an ideal model for the investigation of stage-dependent changes in the secretion of paracrine factors. In vitamin A-deficient animals subsequently injected with vitamin A, over 80% of seminiferous tubules were synchronized within three to five stages of the seminiferous cycle. Following replenishment of vitamin A, spermatogenic stages IV–VI (35 days), VI–VIII (38 days), IX–XII (41 days), I–IV (45 days) and V–VII (48 days) were observed. Despite synchronization of spermatogenesis at all stages, spermatogenesis was markedly impaired when evaluated in a quantitative fashion. At all times evaluated, numbers of round spermatids were reduced compared with age-matched controls. Numbers of pachytene spermatocytes reached control values only after 45 days of vitamin A replenishment. Elongate spermatids were almost totally absent up to 41 days after vitamin A replenishment. Testicular and epididymal weights were also reduced, although testicular weights showed a significant recovery over the time-course of the study. Serum and pituitary concentrations of LH and FSH were raised at the commencement of the study, with serum gonadotrophins returning to control values 48 days after vitamin A replenishment. Both testicular and serum testosterone concentrations in treated animals tended to be higher than in the controls. Although synchronization of spermatogenesis was achieved, testicular testosterone concentrations did not reflect the stage-dependent cyclical changes observed in earlier studies. Testicular concentrations of testosterone were raised throughout the period of observation with the exception of animals synchronized around stages II–IV of the spermatogenic cycle. No correlation between the most frequent stages and intratesticular testosterone was found (r = 0·06, P > 0·1). Previous observations that testosterone concentrations are selectively increased at stages VII–VIII of the spermatogenic cycle are not supported by the present study. Journal of Endocrinology (1989) 123, 403–412


1989 ◽  
Vol 120 (4) ◽  
pp. 423-428 ◽  
Author(s):  
Janine L. Brown ◽  
Prabir K. Chakraborty

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.


1984 ◽  
Vol 59 (4) ◽  
pp. 756-763 ◽  
Author(s):  
WILLIAM B. NEAVES ◽  
LARRY JOHNSON ◽  
JOHN C. PORTER ◽  
C. RICHARD PARKER ◽  
CHARLES S. PETTY

2008 ◽  
Vol 20 (4) ◽  
pp. 505 ◽  
Author(s):  
A. Wagner ◽  
R. Claus

Oestrogens and glucocorticoids are important for spermatogenesis and are regulated via aromatase for oestradiol synthesis and 11β-hydroxysteroid dehydrogenase 2 (11β-HSD 2) as an inactivator of cortisol. In the present study postnatal changes of these two enzymes were monitored together with testicular development and hormone concentrations. Pigs were assigned to three periods: Weeks 0–5, Weeks 5–11 or Weeks 11–17. In Period 1, groups of four piglets were killed after each week. Blood plasma and testes were sampled immediately post mortem. For Periods 2 and 3, groups of six pigs were fitted with vein catheters for daily blood collection. Testes from all pigs were obtained after killing. Levels of testosterone, oestradiol, LH, FSH and cortisol were determined radioimmunologically. The 11β-HSD 2- and aromatase-expressing cells were stained immunocytochemically. All hormones were maximal 2 weeks after birth. A rise of LH, testosterone and oestradiol occurred again at Week 17. FSH and cortisol remained basal. Parallel to the first postnatal rise, the presence of aromatase and 11β-HSD 2 in Leydig cells increased, together with germ and Sertoli cell numbers. Expression was low from 3 to 5 weeks, was resumed after Week 5 and was maximal at Week 17. The amount of 11β-HSD 2 in germ cells was greatest at birth, decreased thereafter and was absent after Week 3.


1977 ◽  
Vol 86 (3) ◽  
pp. 651-658 ◽  
Author(s):  
J. H. Aafjes ◽  
J. C. M. van der Vijver ◽  
R. Docter ◽  
P. E. Schenck

ABSTRACT In 210 subfertile men there existed a significant positive correlation between serum FSH and LH (0.41). No correlation was observed between the gonadotrophin levels and testosterone. In contrast to this FSH as well as LH were negatively correlated with the natural logarithm (In) of the sperm count/ml ejaculate (−0.44 and −0.18, respectively). When the positive correlation which existed between FSH and LH was used to calculate partial correlation coefficients, the coefficient between FSH and ln sperm count did hardly change (−0.41) the coefficient between LH and ln sperm count on the other hand became insignificant (−0.05). This suggests that spermatogenesis influences FSH serum levels in subfertile men by a decreased suppression when sperm production is diminished. Testicular biopsies taken from 97 of these patients were used to determine biopsy scores. These scores showed a significant negative correlation with FSH (−0.34) and a positive one with ln sperm count/ml ejaculate (0.45). Interestingly the biopsy score of 16 patients who fertilized their wives, was found to be higher compared with the score of the other patients who did not fertilize. The number of sperm/ml ejaculate and the FSH values of these 2 groups of biopsied patients were, however, not significantly different. This leads to the conclusion that the biopsy score is a better parameter for the evaluation of oligospermic men than either sperm count or FSH serum values.


Reproduction ◽  
1996 ◽  
Vol 107 (1) ◽  
pp. 137-149 ◽  
Author(s):  
O. E. Okwun ◽  
G. Igboeli ◽  
J. J. Ford ◽  
D. D. Lunstra ◽  
L. Johnson

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