Abstract
The present work aimed to elucidate the influence of thyroid functional status on the alpha 1-adrenoreceptor-induced activation of hepatic metabolic functions. The experiments were performed in either a nonrecirculating liver perfusion system featuring continuous monitoring of portal pressure, PO2, pCa, and pH, or isolated hepatocytes from euthyroid, hyperthyroid, and hypothyroid rats. Hypothyroidism decreased the alpha 1-adrenergic stimulation of respiration, glycogen breakdown, and gluconeogenesis. These effects were accompanied by a decreased intracellular Ca2+ mobilization corroborating that those processes are regulated by the Ca(2+)-dependent branch of the alpha 1-adrenoreceptor signaling pathway. Moreover, in hyperthyroid rats the alpha 1-adrenergic-induced increase in cytosolic Ca2+ was enhanced, and glucose synthesis or mobilization was not altered. The thyroid status influenced neither the alpha 1-adrenergic stimulation of vascular smooth muscle contraction nor the alpha 1-agonist-induced intracellular alkalinization and protein kinase C (PKC) activation. Thus the distinct impairment of the Ca(2+)-dependent branch of the alpha 1-adrenoreceptor signaling pathway by thyroid status provides a useful tool to investigate t...Continue Reading
References
May 29, 1979·Biochemistry·J A ThomasE Racker
Mar 1, 1979·Journal of Cardiovascular Pharmacology·R S Williams, R J Lefkowitz
Nov 1, 1976·Clinical Endocrinology·W J Irvine, A D Toft
Jan 1, 1990·Proceedings of the National Academy of Sciences of the United States of America·P K PangC G Benishin
Apr 1, 1990·Proceedings of the National Academy of Sciences of the United States of America·O ThastrupA P Dawson
Jul 29, 1988·Biochemical and Biophysical Research Communications·C C Malbon, J R Hadcock
Jul 1, 1985·The Journal of Cell Biology·S GrinsteinA Rothstein
Oct 1, 1985·Proceedings of the National Academy of Sciences of the United States of America·J A García-Sáinz, S M Hernández-Sotomayor
Aug 1, 1987·Endocrine Reviews·J H OppenheimerH C Freake
Apr 1, 1985·The Biochemical Journal·H J SeitzS Soboll
Apr 24, 1972·European Journal of Biochemistry·S DiamantE Shafrir
Sep 1, 1981·Molecular and Cellular Endocrinology·J H Exton
Jan 1, 1983·Endocrine Reviews·J P Bilezikian, J N Loeb
Aug 18, 1983·Nature·W H MoolenaarS W de Laat
Oct 1, 1982·The Journal of Cell Biology·T J RinkT Pozzan
Feb 1, 1995·Endocrinology·G CiprésA Martin-Requero
Mar 1, 1994·Trends in Pharmacological Sciences·C FasolatoT Pozzan
Jan 28, 1993·Nature·M J Berridge
Nov 1, 1993·Endocrinology·E UrcelayR Parrilla
Aug 1, 1996·British Journal of Pharmacology·N ButtaM S Ayuso