PREJUNCTIONAL REGULATORY ACTIONS of ANDROGENS ON A HORMONE-SENSITIVE MUSCLE

PREJUNCTIONAL REGULATORY ACTIONS of ANDROGENS ON A HORMONE-SENSITIVE MUSCLE

Autor Yamamoto, L. A. Google Scholar
Lapa, A. J. Google Scholar
Souccar, C. Google Scholar
Instituição Universidade Federal de São Paulo (UNIFESP)
Resumo The influence of androgens and time course of effects induced by hormone deprivation were examined on the spontaneous transmitter release in the levator ani (LA) muscle of 30-180-day-old male rats. the resting membrane potential (RMP) and miniature endplate potentials (mepps) were recorded intracellularly from LA muscle fibers of intact animals or gonadectomized at different ages. in intact animals, the frequency of mepps increased proportionately to the muscle fiber growth up to 60 days, stabilizing thereafter. Gonadectomy at any age did not affect the RMP, but increased the frequency of mepps by 65% to 140%. the effect was detected after 15 days and was unrelated to the degree of muscle atrophy. Independently of the age of gonadectomy control values of mepp frequency were restored after 90 days, while the accompanying postjunctional changes persisted. These results indicate that androgens exert a prejunctional inhibitory influence on the spontaneous transmitter release in the rat LA muscle. the transient nature of the prejunctional effect induced by hormone deprivation indicates an adjustment of nerve terminals to persistent postjunctional alterations. (C) 1994 John Wiley & Sons, Inc.
Assunto ANDROGEN
LEVATOR ANI MUSCLE
MINIATURE END-PLATE POTENTIALS
NEUROMUSCULAR JUNCTION
MOTOR NERVE TERMINALS
ADAPTATION
Idioma Inglês
Data 1994-08-01
Publicado em Muscle & Nerve. New York: John Wiley & Sons Inc, v. 17, n. 8, p. 906-912, 1994.
ISSN 0148-639X (Sherpa/Romeo, fator de impacto)
Editor Wiley-Blackwell
Extensão 906-912
Fonte http://dx.doi.org/10.1002/mus.880170810
Direito de acesso Acesso restrito
Tipo Artigo
Web of Science WOS:A1994NY96600009
URI http://repositorio.unifesp.br/handle/11600/25420

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