Effect of angiotensin II on Ca sup 2+ kinetics and contraction in cultured rat glomerular mesangial cells

Journal Article · Mon Feb 01 04:00:00 EST 1988 · American Journal of Physiology; (USA)

OSTI ID:6808921

Takeda, Katsuji; Meyer-Lehnert, H; Kim, J K; Schrier, R W ^[1]

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1. Univ. of Colorado School of Medicine, Denver (USA)

This in vitro study was undertaken to determine the changes in Ca{sup 2+} kinetics and cell shape of cultured putative glomerular mesangial cells in the rat in response to angoitensin II (ANG II). Intracellular Ca{sup 2+} ((Ca{sup 2+}){sub i}) was measured using quin 2. ANG II-stimulated {sup 45}Ca{sup 2+} efflux was also determined. ANG II induced rapid concentration-dependent increases in (Ca{sup 2+}){sub i} and {sup 45}Ca{sup 2+} efflux. ANG II also induced contraction of mesangial cells as assessed by alterations in cell shape. Even in Ca{sup 2+}-free medium, ANG II increased (Ca{sup 2+}){sub i} and {sup 45}Ca{sub 2+} efflux, but to a lesser extent. Under this condition, contraction of mesangial cells induced by ANG II was also observed. Readdition of extracellular Ca{sup 2+} and the ANG II-induced increase in (Ca{sup 2+}){sub i} caused a second and slower (Ca{sup 2+}){sub i} increase. High potassium (50 mM) induced a change of (Ca{sup 2+}){sub i}, but to a lesser extent compared with the ANG II-induced change. The Ca{sup 2+} channel blocker verapamil partially inhibited ANG II-induced {sup 45}Ca{sup 2+} influx but totally blocked the increase in (Ca{sup 2+}){sub i} induced by high potassium. Verapamil did not inhibit ANG II-stimulated Ca{sup 2+} efflux or the change in cell shape. Dantrolene (10{sup {minus}4} M), a blocker of Ca{sup 2+} release from endoplasmic reticulum, inhibited ANG II-stimulated Ca{sup 2+} efflux and change in cell shape. These results indicate that ANG II rapidly increases (Ca{sup 2+}){sub i} in cultured rat mesangial cells, in part by mobilizing Ca{sup 2+} from dantrolene-sensitive intracellular pools and in part through activation of receptor-operated and voltage-dependent Ca{sup 2+} channels. The (Ca{sup 2+}){sub i} mobilization, however, seems to be the primary modulator of initial glomerular mesangial cell contraction.

• OSTI ID: 6808921
• Journal Information: American Journal of Physiology; (USA), Journal Name: American Journal of Physiology; (USA) Vol. 254:2; ISSN 0002-9513; ISSN AJPHA
• Country of Publication: United States
• Language: English

Related Subjects

551001* -- Physiological Systems-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ALKALINE EARTH ISOTOPES
ANGIOTENSIN
ANIMAL CELLS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
BIOLOGICAL EFFECTS
BODY
CALCIUM 45
CALCIUM ISOTOPES
CARDIOVASCULAR AGENTS
DAYS LIVING RADIOISOTOPES
DRUGS
EVEN-ODD NUCLEI
FILTRATION
GLOBULINS
GLOMERULI
INTERMEDIATE MASS NUCLEI
ISOTOPES
KIDNEYS
KINETICS
MEMBRANE TRANSPORT
MORPHOLOGICAL CHANGES
NUCLEI
ORGANIC COMPOUNDS
ORGANS
PROTEINS
RADIOISOTOPES
REACTION KINETICS
SEPARATION PROCESSES
SHAPE
VASOCONSTRICTORS