| Comparative effects of neonatal exposure of male rats to potent and weak (environmental) estrogens on spermatogenesis at puberty and the relationship to adult testis size and fertility: evidence for stimulatory effects of low estrogen levels. | |
| | |
MedLine Citation:
|
PMID: 11014247 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
This study investigated whether neonatal exposure of male rats to estrogenic compounds altered pubertal spermatogenesis (days 18 and 25) and whether the changes observed resulted in long-term changes in testis size, mating, or fertility (days 90-100). Rats were treated neonatally with a range of doses (0.01-10 microg) of diethylstilbestrol (DES; administered on alternate days from days 2-12), a high dose of octylphenol (OP; 2 mg administered daily from days 2-12) or bisphenol A (Bis-A; 0.5 mg administered daily from days 2-12), or vehicle, while maintained on a standard soy-containing diet. The effect on the same parameters of rearing control animals on a soy-free diet was also assessed as was the effect of administering such animals genistein (4 mg/kg/day daily from days 2-18). Testis weight, seminiferous tubule lumen formation, the germ cell apoptotic index (apoptotic/viable germ cell nuclear volume), and spermatocyte nuclear volume per unit Sertoli cell nuclear volume were used to characterize pubertal spermatogenesis. Compared with (soy-fed) controls, DES administration caused dose-dependent retardation of pubertal spermatogenesis on day 18, as evidenced by decreases in testis weight, lumen formation, and spermatocyte nuclear volume per unit Sertoli cell and elevation of the germ cell apoptotic index. However, the two lowest doses of DES (0.1 and 0.01 microg) significantly increased spermatocyte nuclear volume per unit Sertoli cell. Similarly, treatment with either OP or Bis-A significantly advanced this and some of the other aspects of pubertal spermatogenesis. Maintenance of control animals on a soy-free diet also significantly advanced lumen formation and spermatocyte nuclear volume per unit Sertoli cell compared with controls fed a soy-containing diet. Administration of genistein reversed the stimulatory effects of a soy-free diet and significantly retarded most measures of pubertal spermatogenesis. In general, plasma FSH levels in the treatment groups changed in parallel to the spermatogenic changes (reduced when pubertal spermatogenesis retarded, increased when pubertal spermatogenesis advanced). By day 25, although the changes in FSH levels largely persisted, all of the stimulatory effects on spermatogenesis seen on day 18 in the various treatment groups were no longer evident. In adulthood, testis weight was decreased dose dependently in rats treated neonatally with DES, but only the lowest dose group (0.01 microg) showed evidence of mating (3 of 6) and normal fertility (3 litters). Animals treated neonatally with OP or Bis-A had normal or increased (Bis-A) testis weights and exhibited reasonably normal mating/fertility. Animals fed a soy-free diet had significantly larger testes than controls fed a soy-containing diet, and this difference was confirmed in a much larger study of more than 24 litters, which also showed a significant decrease in plasma FSH levels and a significant increase in body weight in the males kept on a soy-free diet. Neonatal treatment with genistein did not alter adult testis weight, and although most males exhibited normal mating and fertility, a minority did not mate or were infertile. It is concluded that 1) neonatal exposure of rats to low levels of estrogens can advance the first wave of spermatogenesis at puberty, although it is unclear whether this is due to direct effects of the estrogen or to associated elevation of FSH levels; 2) the effect of high doses of OP and Bis-A on these processes is essentially benign; and 3) the presence or absence of soy or genistein in the diet has significant short-term (pubertal spermatogenesis) and long-term (body weight, testis size, FSH levels, and possibly mating) effects on males. |
| | |
Authors:
|
N Atanassova; C McKinnell; K J Turner; M Walker; J S Fisher; M Morley; M R Millar; N P Groome; R M Sharpe |
Related Documents
:
|
17392557 - Soy consumption, markers of inflammation, and endothelial function: a cross-over study ... 11157317 - Soy isoflavones improve plasma lipids in normocholesterolemic and mildly hypercholester... 566837 - The role of dietary protein in hypercholesterolemia and atherosclerosis. 11528367 - Dietary inclusion of whole soy foods results in significant reductions in clinical risk... 23419397 - Zanthoxylum piperitum dc ethanol extract suppresses fat accumulation in adipocytes and ... 11893407 - Effect of t-2 toxin on in vivo lipid peroxidation and vitamin e status in mice. |
Publication Detail:
|
Type: Comparative Study; Journal Article; Research Support, Non-U.S. Gov't |
Journal Detail:
|
Title: Endocrinology Volume: 141 ISSN: 0013-7227 ISO Abbreviation: Endocrinology Publication Date: 2000 Oct |
Date Detail:
|
Created Date: 2000-10-02 Completed Date: 2000-10-31 Revised Date: 2010-04-12 |
Medline Journal Info:
|
Nlm Unique ID: 0375040 Medline TA: Endocrinology Country: UNITED STATES |
Other Details:
|
Languages: eng Pagination: 3898-907 Citation Subset: AIM; IM |
Affiliation:
|
Medical Research Council Human Reproductive Sciences Unit, Center for Reproductive Biology, Edinburgh, Scotland, United Kingdom. |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Aging
/
physiology Animals Animals, Newborn / growth & development, physiology* Apoptosis / physiology Diet Environmental Exposure Estrogens / pharmacology* Fertility / drug effects* Follicle Stimulating Hormone / blood Inhibins / blood Male Organ Size Rats Rats, Wistar Seminiferous Tubules / drug effects Sertoli Cells / cytology Soybeans Spermatogenesis / drug effects* Testis / anatomy & histology*, cytology, drug effects, physiology |
| Chemical | |
Reg. No./Substance:
|
0/Estrogens; 57285-09-3/Inhibins; 9002-68-0/Follicle Stimulating Hormone |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Thyroid hormone acts directly on growth plate chondrocytes to promote hypertrophic differentiation a...
Next Document: 17beta-estradiol, but not raloxifene, decreases thrombomodulin in the antithrombotic protein C pathw...