Ultrastructural development of fetal rabbit testis

Bjerregaard, Peter; Bro-Rasmussen, Finn; Reumert, T

doi:10.1007/bf00307473

Cited by 24 publications

(13 citation statements)

References 14 publications

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“…Degeneration of germ cells has been described in reports on the fetal (Chretien, 1966;Gondos and Conner, 1973;Bjerregaard et al, 1974;Jost and Magre, 1984) and postnatal (Gondos et al, 1973) rabbit testis. The present study revealed that the degeneration index for germ cells remained constant during the first 6 postnatal weeks but showed a sharp rise at week 7.…”

Section: Discussionmentioning

confidence: 88%

Morphometric study of the prepubertal rabbit testis: Germ cell numbers and seminiferous tubule dimensions

1991

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Testes from rabbits aged 1-9 weeks were examined by light microscopy. Changes in seminiferous tubule dimensions, testicular volume, and volume fraction of tubules were assessed. Germ cells and Sertoli cells were counted in round tubular cross sections and total germ cell number in each testis was estimated. Mitotic, meiotic, and degenerative activities of germ cells as well as their basal or central positions within tubules were quantified. A marked, steady increase in testis volume and in tubular length and volume occurred over the prepubertal period; but diameter underwent no significant increase and in fact decreased until week 4. Overall, tubules lengthened 40-fold and testis volume increased 25-fold; the percentage volume of the testis occupied by tubules rose from one-third neonatally to three-fifths at the onset of spermatogenesis. The ratio of germ cells to total tubular (germ and Sertoli) cells was lowest at 3 weeks. However, the total number of germ cells increased little until 3 weeks, after which it rose at a sharp rate commensurate with testis volume. Percentage of germ cells in mitosis peaked sharply at 3 weeks, dropped in subsequent weeks, and then rose at 7 weeks at the initiation of spermatogenesis. Importantly, the surge in mitosis at 3 weeks was followed by a redistribution of germ cells to a predominantly basal location from 3 to 7 weeks. Meiotic activity was sparse at 7 weeks and became abundant by 9 weeks. Germ cell degeneration remained relatively constant during weeks 1 through 6, with an increase at 7 weeks.

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Section: Discussionmentioning

confidence: 88%

Morphometric study of the prepubertal rabbit testis: Germ cell numbers and seminiferous tubule dimensions

1991

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“…Vulnerability of male rabbit fetuses to anti-androgens during the exposure window used in the current study is logical because it encompasses androgendependent differentiation. Interstitial cells (future Leydig cells) of the fetal rabbit testis remain undifferentiated until GD 17, and perhaps begin hormone secretion near GD 20 (Bjerregaard et al 1974, Gondos 1974, Catt et al 1975. Indifferent supporting cells (future Sertoli cells) start to undergo morphological and biochemical changes indicative of endocrine activity approximately by GD 20 (Gondos et al 1973, Gondos 1974.…”

Section: Discussionmentioning

confidence: 99%

“…Also, perinatal developmental events are well documented for the rabbit (Bloch et al 1971, Gondos et al 1973, Bjerregaard et al 1974, Gondos 1974, Catt et al 1975. Furthermore, use of rabbits (in contrast to rodents) facilitates multiple evaluations of seminal quality and sexual capacity.…”

Section: Introductionmentioning

confidence: 99%

Disruption of sexual function, FSH secretion, and spermiogenesis in rabbits following developmental exposure to vinclozolin, a fungicide

Veeramachaneni¹,

Palmer²,

Amann³

et al. 2006

Reproduction

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We studied sequelae of prenatal plus infantile exposure of male rabbits to vinclozolin, because it is ingested by women and children. Female Dutch-Belted rabbits (7 -10/group) were treated daily per orum from gestation day 15 through post-natal week 4 to provide 0, 7.2, or 72 mg vinclozolin/kg dam's body weight/day. Vinclozolin had no effect on maintenance of pregnancy, growth of pups, age at testicular descent or weight of organs. Concentrations of serum LH or testosterone at 6, 12, or 24 weeks of age were unaffected. However, FSH was lower (P < 0.05) in both vinclozolin groups at all three ages. Following injection of GnRH at 12 or 24 weeks, the increase in FSH was less (P < 0.05) in both vinclozolin groups, as was testosterone at 12 weeks of age. After full sexual maturity, 2 of 7 low dose rabbits were uninterested in female or male teasers and never achieved erection or ejaculation. Overall, rates of ejaculation failure were: control 0% (0/48), low dose 29% (12/42), and high dose 5% (3/60). Daily sperm production per gram of testis and total number of sperm per ejaculate in both vinclozolin groups were similar (P > 0.1) to controls. However, semen from vinclozolin rabbits contained over two times more (P < 0.05) morphologically abnormal spermatozoa, mostly nuclear and acrosomal defects, than semen from controls. Seminiferous tubules with degenerative changes were more frequent (P < 0.05) in vinclozolin rabbits than in controls. Lesions included syncytia of spherical spermatids and desquamation of germ cells. Hence, developmental exposure to vinclozolin caused presumably permanent changes in copulatory ability, secretion of FSH, and spermiogenesis.

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“…Previous studies in the rabbit have shown that fetal Leydig cells have ultrastructural features characteristic of steroid-secreting cells [6,7]. Moreover, active testosterone synthesis occurs during this period [7,21,3 13.…”

Section: Discussionmentioning

confidence: 99%