Document Detail


Effect of bullfrog LH and FSH on newt testes under different temperatures.
MedLine Citation:
PMID:  15242745     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Environmental temperature plays important roles for amphibian gonadal function. In this study, we examined the responses of testicular tissue of adult male newts (Cynops pyrrhogaster) to amphibian gonadotropins both in vitro and in vivo under different temperatures. When minced testes were incubated in vitro at different temperatures (8-37 degrees C) under an atmosphere of 95% O(2)-5% CO(2) for 3h with bullfrog luteinizing hormone (LH) or follicle-stimulating hormone (FSH), LH stimulated testosterone production more than FSH. The testosterone production increased as the incubation temperature increased. Hypophysectomized newts were injected with bullfrog LH or FSH and maintained at 8 or 18 degrees C. In the 18 degrees C group, the testicular weight of the hypophysectomized control decreased when compared with that of with the intact control. The testicular weight of the LH-treated hypophysectomized group decreased more than that of the hypophysectomized control, indicating that LH induced the evacuation of mature spermatozoa from the testes of LH-treated hypophysectomized newts. In the FSH-treated newts, the testicular weight was greater than that in the hypophysectomized control, and was maintained at a value similar to that of the intact control. In the 8 degrees C group, there was no significant difference in testicular size among the intact control, hypophysectomized control, and FSH-treated newts. LH strongly induced spermiation as it did at 18 degrees C. The plasma testosterone level in the hypophysectomized newts decreased dramatically, but LH was effective in restoring it. Its effect was more potent at 8 degrees C than at 18 degrees C. On the other hand, FSH did not induce a significant increase in the plasma testosterone levels at either temperatures. The results indicate a temperature-dependent difference in responsiveness of the testis both in vitro and in vivo to LH and FSH.
Authors:
Shigeyasu Tanaka; Makoto Sakai; Masa-Aki Hattori; Sakae Kikuyama; Katsumi Wakabayashi; Yoichi Hanaoka
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  General and comparative endocrinology     Volume:  138     ISSN:  0016-6480     ISO Abbreviation:  Gen. Comp. Endocrinol.     Publication Date:  2004 Aug 
Date Detail:
Created Date:  2004-07-09     Completed Date:  2005-01-13     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:  1-7     Citation Subset:  IM    
Affiliation:
Department of Biology, Faculty of Science, Shizuoka University, Shizuoka 422-8529, Japan. sbstana@ipc.shizuoka.ac.jp
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MeSH Terms
Descriptor/Qualifier:
Animals
Follicle Stimulating Hormone / pharmacology*
Hypophysectomy
Luteinizing Hormone / pharmacology*
Male
Organ Size / drug effects
Rana catesbeiana
Salamandridae
Seasons
Temperature
Testis / drug effects*,  growth & development,  metabolism
Testosterone / blood,  metabolism
Tissue Fixation
Chemical
Reg. No./Substance:
58-22-0/Testosterone; 9002-67-9/Luteinizing Hormone; 9002-68-0/Follicle Stimulating Hormone

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


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