Neurofilament expression in cultured rat adenohypophysial cells

摘要

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. Copyright (C) 2001 S. Karger AG, Basel. [References: 23]