Cellular regulation of follicle-stimulating hormone (FSH) binding in rat seminiferous tubules
- Univ. of Turku (Finland)
Stage-specific binding of follicle-stimulating hormone (FSH) was measured in rat seminiferous tubules. The binding in single-point assays was over 3-fold higher (P less than 0.05) in stages XIII to I than in stages VI to VII of the epithelial cycle. No difference was found between the equilibrium association constants (Ka) of FSH binding in stages XIV to IV (10 +/- 1.9 X 10(9) 1/mol) and VII to VIII (9.2 +/- 0.6 X 10(9) 1/mol, mean +/- SEM, n = 5). In another experiment, the testes were dosed locally with 3 Gy of 4 MV x-irradiation to selectively lower the number of spermatogonia. After irradiation, FSH binding in staged seminiferous tubule segments was measured when the desired types of spermatogenic cells were reduced in number. Seven days after irradiation when differentiating spermatogonia and preleptotene spermatocytes were reduced in number, FSH binding was decreased in all stages of the cycle, but the cyclic variation remained. Seventeen days after irradiation when intermediate and type B spermatogonia and spermatocytes up to diplotene of stage XIII showed low numbers, FSH binding was decreased in all stages of the cycle and the stage-dependent variation disappeared. At 38 days when pachytene spermatocytes and early spermatids were reduced in number, similar results were found. But at 52 days postirradiation when all spermatids were low in number, FSH binding was slightly elevated compared with days 17 and 38. There were no significant differences in serum FSH or LH levels between irradiated and non-irradiated animals. These findings suggest that all spermatogenic cell types may stimulate FSH binding in the Sertoli cells.
- OSTI ID:
- 6214565
- Journal Information:
- Journal of Andrology; (USA), Journal Name: Journal of Andrology; (USA) Vol. 11:4; ISSN 0196-3635; ISSN JOAND
- Country of Publication:
- United States
- Language:
- English
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63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMALS
BIOCHEMICAL REACTION KINETICS
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
BODY
ELECTROMAGNETIC RADIATION
FSH
GAMETES
GERM CELLS
GONADOTROPINS
GONADS
HORMONES
IONIZING RADIATIONS
KINETICS
MALE GENITALS
MAMMALS
ORGANS
PEPTIDE HORMONES
PITUITARY HORMONES
RADIATION EFFECTS
RADIATIONS
RATS
REACTION KINETICS
RODENTS
SPERMATOGONIA
SPERMATOZOA
TESTES
VERTEBRATES
X RADIATION