Role of calcium in the dopaminergic effect on the proximal convoluted tubule of rat kidney

Conference · Sat Mar 01 00:00:00 EST 1986 · Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States)

OSTI ID:5393338

Chan, Y L; Chatsudthipong, V; Su-Tsai, S M; von Riotte, A

Microperfusion studies have shown that dopamine inhibits fluid and bicarbonate absorption in the rate proximal tubule. These studies are designed to examine the cellular mechanism underlying the proximal cellular response to dopamine action. In the isolated proximal cells, dopamine, in the concentration of 10/sup -6/M or less, had no effect on cAMP production. However, dopamine could increase cytosolic calcium concentration (from 90 nM to 210 nM) as measured by fluorospectrometry with fura-2 as a calcium indicator. Ca-45 flux studies have shown that dopamine could increase initial influx but not the steady state uptake of Ca. Dopamine could also increase efflux of Ca. In situ microperfusion of proximal tubule and peritubular capillaries has demonstrated that Ca ionophore, A23187 (10/sup -6/M), could simulate the inhibitory effects of dopamine on fluid and biocarbonate absorption. There was no additive effect observed when both agents were added together in the capillary perfusate. Removal of calcium from the perfusate could partially blunt the effect of dopamine. These results suggest that intracellular calcium plays a crucial role in the dopaminergic regulation of proximal tubular transport.

• Research Organization: Univ. of Illinois College of Medicine, Chicago
• OSTI ID: 5393338
• Report Number(s): CONF-8604222-; TRN: 86-028357
• Journal Information: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States), Vol. 45:3; Conference: 70. annual meeting of the Federation of American Society for Experimental Biology, St. Louis, MO, USA, 13 Apr 1986
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
ACID CARBONATES
ABSORPTION
CALCIUM
BIOCHEMICAL REACTION KINETICS
DOPAMINE
BIOLOGICAL EFFECTS
CALCIUM 45
PERFUSED TISSUES
RATS
TRACER TECHNIQUES
TUBULES
ALKALINE EARTH ISOTOPES
ALKALINE EARTH METALS
AMINES
ANIMAL TISSUES
ANIMALS
AROMATICS
AUTONOMIC NERVOUS SYSTEM AGENTS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BODY
CALCIUM ISOTOPES
CARDIOTONICS
CARDIOVASCULAR AGENTS
DAYS LIVING RADIOISOTOPES
DRUGS
ELEMENTS
EVEN-ODD NUCLEI
HYDROXY COMPOUNDS
INTERMEDIATE MASS NUCLEI
ISOTOPE APPLICATIONS
ISOTOPES
KIDNEYS
KINETICS
MAMMALS
METALS
NEUROREGULATORS
NUCLEI
ORGANIC COMPOUNDS
ORGANS
PHENOLS
POLYPHENOLS
RADIOISOTOPES
REACTION KINETICS
RODENTS
SYMPATHOMIMETICS
TISSUES
VERTEBRATES
550201* - Biochemistry- Tracer Techniques