Insulin and IGF-I actions on IGF-I receptor in seminiferous tubules from immature rats.

Escott, Gustavo Monteiro; de Castro, Alexandre Luz; Jacobus, Ana Paula; Loss, E S

Escott, Gustavo Monteiro; de Castro, Alexandre Luz; Jacobus, Ana Paula; Loss, E S.

Afiliação

Escott GM; Laboratório de Endocrinologia Experimental e Eletrofisiologia, Departamento de Fisiologia, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Brazil.
de Castro AL; Laboratório de Endocrinologia Experimental e Eletrofisiologia, Departamento de Fisiologia, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Brazil.
Jacobus AP; Centro Universitário Metodista do IPA, Brazil.
Loss ES; Laboratório de Endocrinologia Experimental e Eletrofisiologia, Departamento de Fisiologia, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Brazil. Electronic address: eloss@ufrgs.br.

Biochim Biophys Acta ; 1838(5): 1332-7, 2014 May.

Article em En | MEDLINE | ID: mdl-24530896

RESUMO

Insulin and insulin-like growth factor 1 (IGF-I) are capable of activating similar intracellular pathways. Insulin acts mainly through its own receptor, but can also activate the IGF-I receptor (IGF-IR). The aim of this study was to investigate the involvement of the IGF-IR in the effects of insulin and IGF-I on the membrane potential of immature Sertoli cells in whole seminiferous tubules, as well as on calcium, amino acid, and glucose uptake in testicular tissue of immature rats. The membrane potential of the Sertoli cells was recorded using a standard single microelectrode technique. In calcium uptake experiments, the testes were pre-incubated with (45)Ca(2+), with or without JB1 (1 µg/mL), and then incubated with insulin (100 nM) or IGF-I (15 nM). In amino acid and glucose uptake experiments, the gonads were pre-incubated with or without JB1 (1 µg/mL) and then incubated with radiolabeled amino acid or glucose analogues in the presence of insulin (100 nM) or IGF-I (15 nM). The blockade of IGF-IR with JB1 prevented the depolarising effects of both insulin and IGF-I on membrane potential, as well as the effect of insulin on calcium uptake. JB1 also inhibited the effects of insulin and IGF-I on glucose uptake. The effect of IGF-I on amino acid transport was inhibited in the presence of JB1, whereas the effect of insulin was not. We concluded that while IGF-I seems to act mainly through its cognate receptor to induce membrane depolarisation and calcium, amino acid and glucose uptake, insulin appears to be able to elicit its effects through IGF-IR, in seminiferous tubules from immature rats.

Assuntos

Fator de Crescimento Insulin-Like I/metabolismo; Insulina/metabolismo; Receptor IGF Tipo 1/metabolismo; Túbulos Seminíferos/metabolismo; Aminoácidos/metabolismo; Animais; Transporte Biológico; Cálcio/metabolismo; Membrana Celular/metabolismo; Glucose/metabolismo; Masculino; Potenciais da Membrana; Ratos; Ratos Wistar; Células de Sertoli/metabolismo

Palavras-chave

Amino acid transport; Calcium uptake; Glucose transport; Insulin-like growth factor 1; Membrane potential; Sertoli cell

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Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Túbulos Seminíferos / Fator de Crescimento Insulin-Like I / Receptor IGF Tipo 1 / Insulina Limite: Animals Idioma: En Revista: Biochim Biophys Acta Ano de publicação: 2014 Tipo de documento: Article País de afiliação: Brasil País de publicação: Holanda

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