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

Journal Article · Mon Feb 01 00:00:00 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), Vol. 254:2; ISSN 0002-9513
• Country of Publication: United States
• Language: English

Related Subjects

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