Neurofilament expression in cultured rat adenohypophysial cells.
The aim of the present work was to investigate in cultured rat adenohypophysial cells: a) the presence of neurofilaments of 200 kDa (NF-H), b) the effect of thyroid hormone (T(3)) and thyrotropin releasing hormone (TRH) on the expression of NF-H and c) the possible role of NF-H on thyrotropin (TSH) secretion. The presence of NF-H was observed by immunocytochemistry in cultured rat adenohypophysial cells. The exposure to T(3) for 12 h produced a significant increase in NF-H expression; whereas incubation with TRH or T(3)+TRH resulted in no change. The cells treated with T(3) or TRH or T(3)+TRH for 24 h showed no alteration. However, incubation for 48 h with TRH or T(3)+TRH caused significant decrease in NF-H expression. Incubation with NF-H antibodies produced a significant inhibition of calcium-induced TSH release in digitonin-permeabilized adenohypophysial cells. These results provide evidence that NF-H is present in cultured rat adenohypophysial cells, and that T(3) and TRH can modify NF-H expression. It can be suggested that in cultured adenohypophysial cells, NF-H may play a role in the secretory process.
Department of Physiology and Pharmacology, Centro de Ciencias Básicas. Universidad Autónoma de Aguascalientes, Aguascalientes Ags. (México). jlquinta@correo.uaa.mx
J L
JL
Quintanar
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Salinas
D000818:Animals; D002478:Cells, Cultured; D005260:Female; D007150:Immunohistochemistry; D007382:Intermediate Filaments / Q000737:chemistry / Q000648:ultrastructure*; D016900:Neurofilament Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D010903:Pituitary Gland, Anterior / Q000166:cytology / Q000378:metabolism* / Q000648:ultrastructure; D051381:Rats; D017208:Rats, Wistar; D013972:Thyrotropin / Q000378:metabolism; D013973:Thyrotropin-Releasing Hormone / Q000494:pharmacology*; D013997:Time Factors; D014284:Triiodothyronine / Q000494:pharmacology*
D016900:Neurofilament Proteins; D014284:Triiodothyronine; C051774:neurofilament protein H; D013973:Thyrotropin-Releasing Hormone; D013972:Thyrotropin