Document Detail


Effect of long term deprivation of luteinizing hormone on Leydig cell volume, Leydig cell number, and steroidogenic capacity of the rat testis.
MedLine Citation:
PMID:  3197648     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Leydig cells atrophy, losing cytoplasmic volume and the capacity for testosterone secretion, within 1-2 weeks of LH deprivation. We investigated the effects of long term (0-16 weeks) LH deprivation on the volume of an average Leydig cell, the volume of Leydig cells per testis, the number of Leydig cells per testis, and testosterone secretion by in vitro perfused testes. Endogenous LH was suppressed in adult rats by testosterone/estradiol-filled (TE) Silastic implants. The presence of Leydig cells in testes was verified by 1) morphological examination using light and electron microscopy, 2) histochemical localization of 3 beta-hydroxysteroid dehydrogenase activity (3 beta HSD), and 3) conversion of pregnenolone to progesterone by in vitro perfused testes. Marked quantitative differences existed in Leydig cell morphology among control and treated rats. The volume of an average Leydig cell and the total volume of Leydig cells per testis decreased (P less than 0.01) rapidly and progressively after TE implantation. At 16 weeks, the average Leydig cell lost 90% of its cytoplasmic volume and 65% of its nuclear volume. Analysis of variance failed to detect a significant decline in Leydig cell number per testis, despite a 16% reduction from the value in control rats (22.2 +/- 1.5 x 10(6)) in rats treated for 16 weeks (18.7 +/- 1.5 x 10(6)). After TE implantation, LH-stimulated testosterone secretion by in vitro perfused testes diminished (P less than 0.01) rapidly to 5% of the control values at 1 week and less than 0.3% of the control value from 4-16 weeks. In contrast, 25% of 3 beta HSD activity was retained (P less than 0.01 vs. controls) at 16 weeks, based on the rate of pregnenolone conversion to progesterone. Moreover, testes of treated rats secreted progesterone at a rate twice that of controls, when the steroid secretion rates were expressed per volume of Leydig cell cytoplasm. Loss of the testosterone-secreting capacity of testes after LH withdrawal was associated with a loss in the volume, but not a significant loss in the number, of Leydig cells. Thus, LH was required to maintain the differentiated structure and function of Leydig cells, but was not required to maintain the overwhelming majority of Leydig cells in the adult rat testis through 16 weeks. Moreover, at least one steroidogenic enzyme, 3 beta HSD, was retained by Leydig cells after long term LH deprivation.
Authors:
D S Keeney; S M Mendis-Handagama; B R Zirkin; L L Ewing
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Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Endocrinology     Volume:  123     ISSN:  0013-7227     ISO Abbreviation:  Endocrinology     Publication Date:  1988 Dec 
Date Detail:
Created Date:  1989-01-17     Completed Date:  1989-01-17     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  0375040     Medline TA:  Endocrinology     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  2906-15     Citation Subset:  AIM; IM    
Affiliation:
Department of Population Dynamics, Johns Hopkins University School of Hygiene and Public Health, Baltimore, Maryland 21205.
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MeSH Terms
Descriptor/Qualifier:
3-Hydroxysteroid Dehydrogenases / metabolism
Animals
Cell Count
Cell Nucleus / ultrastructure
Cytoplasm / ultrastructure
Estradiol / pharmacology
Histocytochemistry
Ketosteroids / biosynthesis
Leydig Cells / ultrastructure*
Luteinizing Hormone / physiology*
Male
Microscopy, Electron
Pregnenolone / metabolism
Progesterone / metabolism
Rats
Rats, Inbred Strains
Testis / cytology,  drug effects,  metabolism*
Testosterone / biosynthesis*,  pharmacology,  secretion
Grant Support
ID/Acronym/Agency:
HD-06268/HD/NICHD NIH HHS; HD-07204/HD/NICHD NIH HHS; HD-07276/HD/NICHD NIH HHS
Chemical
Reg. No./Substance:
0/Ketosteroids; 145-13-1/Pregnenolone; 50-28-2/Estradiol; 57-83-0/Progesterone; 58-22-0/Testosterone; 9002-67-9/Luteinizing Hormone; EC 1.1.-/3-Hydroxysteroid Dehydrogenases

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