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

Conference · Fri May 01 00:00:00 EDT 1987 · Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States)

OSTI ID:6073475

Cornwell, T L; Rashatwar, S S; Lincoln, T M

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 +/ efflux or resequestration possibly through the stimulation of a Ca/sup 2 +/ ATPase pump.

• Research Organization: Univ. of South Alabama, Mobile
• OSTI ID: 6073475
• Report Number(s): CONF-870644-
• Journal Information: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States), Journal Name: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States) Vol. 46:6; ISSN FEPRA
• Country of Publication: United States
• Language: English

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550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ACID ANHYDRASES
ALKALINE EARTH METAL COMPOUNDS
ANIMAL CELLS
AORTA
ARTERIES
ATP-ASE
BIOLOGICAL FUNCTIONS
BLOOD VESSELS
BODY
CALCIUM COMPOUNDS
CARBOHYDRATES
CARDIOVASCULAR SYSTEM
CELL CULTURES
ENZYME ACTIVITY
ENZYMES
FLUORESCENCE
FUNCTIONS
GUANYLIC ACID
HYDROLASES
INOSITOL
INOSITOLS
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
LUMINESCENCE
MONOSACCHARIDES
MUSCLES
NUCLEOTIDES
ORGANIC COMPOUNDS
ORGANS
PHOSPHOHYDROLASES
PHOSPHORUS-GROUP TRANSFERASES
PHOSPHOTRANSFERASES
PROTEINS
SACCHARIDES
SECRETION
TIME DEPENDENCE
TRACER TECHNIQUES
TRANSFERASES
TRITIUM COMPOUNDS