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Exp Clin Endocrinol Diabetes 1990; 96(5): 149-156
DOI: 10.1055/s-0029-1211004
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© J. A. Barth Verlag in Georg Thieme Verlag KG Stuttgart · New York

Influence of Hypothyroidism on In-Vitro Testicular Steroidogenesis in Adult Rats

S. Andó, M. L. Panno, E. Beraldi2 , G. Tarantino, M. Salerno, S. Palmero1 , M. Prati, E. Fugassa1
  • 1Department of Cell Biology, University of Calabria, Arcavacata di Rende-Cosenza, Institute for the study of hereditary and deficiency deseases, C.N.R.-Cosenza/Italy
  • 2Institute of Physiology, General University of Genova, Institute for the study of hereditary and deficiency deseases, C.N.R.-Cosenza/Italy
Further Information

Publication History

1989

Publication Date:
16 July 2009 (online)

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Summary

The influence of hypothyroidism on testicular steroidogenesis was investigated by 3valuating the production of testosterone and its precursors by isolated testes from adult male rats. Animals were made hypothyroid starting from the 4 th week of life either by daily oral administration of 0.1% methimazole (MMI) or by surgical thyroidectomy (TZ). Half of the thyroidectomized rats were i.p. injected with 3γ T3/100 g body weight on alternate days during the last three weeks before sacrifice.

Hypothyroidism is associated with a severe retardation of body growth, which appears more marked in thyroidectomized than in MMI treated rats; no significant variations in testis weight are observed. Administration of T3 does not completely restore body weight.

A significant decrease in the “in vitro” production of testosterone and its precursors by testes isolated from hypothyroid rats is observed. This effect is more evident in thyroidectomized rats where a marked drop in the “in vitro” production of some testosterone Δ4 precursors is associated with the increase in DHEA/Δ4 ratio. T3 injection to thyroidectomized rats only partially restores the “in vitro” testosterone production.

Results suggest that as the degree of hypothyroidism became more severe, the rate of testosterone production decreases and testicular steroidogenesis changes from the Δ4 to Δ5 metabolic pathway is a consequence of the impairement of 3-β-ol-dehydrogenase activity.

Key words

Hypothyroidism - Testicular steroidogenesis

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