Differential effects of thyroid hormone on renin secretion,
content, and mrna in rat juxtaglomerular cells.
Ichihara, Atsuhiro, Hiroyuki Kobori, Yutaka Miyashita, Matsuhiko
Hayashi, and Takao Saruta.
Department of Internal Medicine, School of Medicine,Keio
University, Tokyo 160, Japan
APStracts 4:0237E, 1997.
The effects of thyroid hormone on renin secretion, renin content, and
renin mRNA levels in juxtaglomerular cells harvested from rat kidneys
were determined by radioimmunoassays and reverse transcriptase
-polymerase chain reaction. Despite a lack of immediate effect,
incubation with triiodothyronine dose-dependently increased renin
secretion during the first 6 h and elevated renin content and renin
mRNA levels during the subsequent period. Simultaneous incubation
with triiodothyronine and the calcium ionophore A23187 abolished the
increase in renin secretion and attenuated the increase in renin
content but did not affect the increase in renin mRNA levels. During
simultaneous incubation with triiodothyronine and the adenylate
cyclase inhibitor SQ22536 or membrane-soluble cGMP, the increases in
renin secretion, content, and mRNA were similar to those observed in
the presence of triiodothyronine alone, except for a cGMP-induced
attenuation of the increase in renin secretion. These findings
suggest that thyroid hormone stimulates renin secretion by
juxtaglomerular cells through the calcium-dependent mechanism, while
the stimulation of renin gene expression by thyroid hormone does not
involve intracellular calcium or cyclic nucleotides.
Received 25 June 1997; accepted in final form 23 October 1997.
APS Manuscript Number E298-7.
Article publication pending Am. J. Physiol. (Endocrinol. Metab.).
ISSN 1080-4757 Copyright 1997 The American Physiological Society.
Published in APStracts on 14 November 1997