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Title: Atriopeptin II and 8-bromo-cGMP lower Ca/sup 2 +/ in cultured aortic smooth muscle cells

Atriopeptin II and 8-bromo-cGMP lower Ca/sup 2 +/ in cultured aortic smooth muscle cells Atriopeptin II (ANP) or 8-Bromo-cGMP (8-Br-cGMP) decreased the levels of intracellular Ca/sup 2 +/ in Angiotensin II- (Ang) or K/sup +/-stimulated cultured rat aortic smooth muscle cells. Cytoplasmic Ca/sup 2 +/, measured by fura-2 fluorescence, was maximal at 30 to 60 sec following the addition of either Ang or KCl. Pretreatment of smooth muscle cells with ANP or 8-Br-cGMP diminished peak levels of Ca/sup 2 +/ in response to Ang or KCl. Because the source of Ca/sup 2 +/ mobilized by KCl was extracellular while that mobilized by Ang was intracellular, these results suggested that ANP and 8-Br-cGMP did not inhibit the mobilization of Ca/sup 2 +/. This was further supported by studies on the effects of ANP and 8-Br-cGMP on inositol polyphosphate production in cells labelled with /sup 3/H-inositol. Ang, but not KCl, produced time-dependent increases in inositol polyphosphates. On the other hand, they have observed that cGMP-dependent protein kinase (cGPK), but not cAMP-dependent protein kinase, caused a 4-fold stimulation of Ca/sup 2 +/ ATPase activity in crude microsomal fractions from cultured rat aortic smooth muscle cells. These results suggest that ANP and 8-Br-cGMP may lower Ca/sup 2 +/ mobilized by Ang or KCl by enhancing Ca/sup 2 +/ more » efflux or resequestration possibly through the stimulation of a Ca/sup 2 +/ ATPase pump. « less
Authors: ; ;
Publication Date:
OSTI Identifier:6073475
Report Number(s):CONF-870644-
Journal ID: CODEN: FEPRA; TRN: 87-037197
Resource Type:Conference
Data Type:
Resource Relation:Journal Name: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States); Journal Volume: 46:6; Conference: 78. annual meeting of the American Society of Biological Chemists conference, Philadelphia, PA, USA, 7 Jun 1987
Research Org:Univ. of South Alabama, Mobile
Country of Publication:United States
Language:English
Subject: 59 BASIC BIOLOGICAL SCIENCES; ATP-ASE; ENZYME ACTIVITY; CALCIUM COMPOUNDS; SECRETION; GUANYLIC ACID; BIOLOGICAL FUNCTIONS; PROTEINS; ANIMAL CELLS; AORTA; CELL CULTURES; FLUORESCENCE; INOSITOL; MUSCLES; PHOSPHOTRANSFERASES; TIME DEPENDENCE; TRACER TECHNIQUES; TRITIUM COMPOUNDS; ACID ANHYDRASES; ALKALINE EARTH METAL COMPOUNDS; ARTERIES; BLOOD VESSELS; BODY; CARBOHYDRATES; CARDIOVASCULAR SYSTEM; ENZYMES; FUNCTIONS; HYDROLASES; INOSITOLS; ISOTOPE APPLICATIONS; LABELLED COMPOUNDS; LUMINESCENCE; MONOSACCHARIDES; NUCLEOTIDES; ORGANIC COMPOUNDS; ORGANS; PHOSPHOHYDROLASES; PHOSPHORUS-GROUP TRANSFERASES; SACCHARIDES; TRANSFERASES 550201* -- Biochemistry-- Tracer Techniques