Document Detail


In vitro inhibition of estradiol secretion of tadpole ovaries by cyanoketone.
MedLine Citation:
PMID:  3258837     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
We have demonstrated the presence of delta 5-3 beta-hydroxysteroid dehydrogenase (HSD) activity in tadpole ovaries of Rana catesbeiana. In the present study, we wish to determine whether estradiol (E2) secretion of tadpole ovaries could be influenced by cyanoketone (CK), a specific inhibitor of delta 5-3 beta-HSD. R catesbeina tadpoles at the premetamorphic climax were used, and pooled ovaries were incubated, 30 mg/tube, with CK at dosages of 0, 0.001, 0.01, 0.1, 1, and 10 micrograms/ml of Krebs-Ringer bicarbonate buffer for 6 hr. Media were collected for assay of E2 by radioimmunoassay (RIA). Results showed an inhibition of E2 secretion by CK that was positively correlated with CK dosage, but plateaued at doses of 0.1 microgram/ml and higher. This finding was comparable to that of G.F. Young, H. Kagawa, and Y. Nagahama (1982, Gen. Comp. Endocrinol. 47, 357-360) on adult fish ovaries. However, adult vertebrates depend on gonadotropins to regulate secretion of E2 while tadpoles, being immature, might secrete E2 independently of pituitaries. When the histochemical test for delta 5-3 beta-HSD activity was performed on in vitro CK-treated ovaries, there was a decrease of enzyme activity by CK. The RIA and histochemical findings may contribute to the concept of sex transformation in which a disturbance of steroidogenesis may induce sex reversal from females to males, at least in tadpoles.
Authors:
C Y Hsu; L T Chang; N W Yu; H H Ku; M H Lu
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Publication Detail:
Type:  In Vitro; Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  General and comparative endocrinology     Volume:  69     ISSN:  0016-6480     ISO Abbreviation:  Gen. Comp. Endocrinol.     Publication Date:  1988 Jan 
Date Detail:
Created Date:  1988-06-02     Completed Date:  1988-06-02     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0370735     Medline TA:  Gen Comp Endocrinol     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  41-5     Citation Subset:  IM    
Affiliation:
Department of Biomorphics, National Defense Medical Center, Taipei, Taiwan, Republic of China.
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MeSH Terms
Descriptor/Qualifier:
Androstenols / pharmacology*
Animals
Cyanoketone / pharmacology*
Estradiol / secretion*
Female
Histocytochemistry
Larva / drug effects,  metabolism
Ovary / drug effects,  secretion*
Radioimmunoassay
Rana catesbeiana / metabolism*
Chemical
Reg. No./Substance:
0/Androstenols; 4248-66-2/Cyanoketone; 50-28-2/Estradiol

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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