Angiotensin 2 directly increases rabbit renal brush-border membrane sodium transport: Presence of local signal transduction system

Journal Article · Wed May 01 04:00:00 EDT 1991 · Journal of Membrane Biology; (United States)

DOI:https://doi.org/10.1007/BF01872738· OSTI ID:5162870

Morduchowicz, G A; Sheikh-Hamad, D; Dwyer, B E; Stern, N; Jo, O D; Yanagawa, N ^[1]

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1. Sepulveda Veterans Administration, CA (USA)

In the present study, the authors have examined the direct actions of angiotensin II (AII) in rabbit renal brush border membrane (BBM) where binding sites for AII exist. Addition of AII (10(-11)-10(-7) M) was found to stimulate 22Na+ uptake by the isolated BBM vesicles directly. All did not affect the Na(+)-dependent BBM glucose uptake, and the effect of AII on BBM 22Na+ uptake was inhibited by amiloride, suggesting the involvement of Na+/H+ exchange mechanism. BBM proton permeability as assessed by acridine orange quenching was not affected by AII, indicating the direct effect of AII on Na+/H+ antiport system. In search of the signal transduction mechanism, it was found that AII activated BBM phospholipase A2 (PLA) and that BBM contains a 42-kDa guanine nucleotide-binding regulatory protein (G-protein) that underwent pertussis toxin (PTX)-catalyzed ADP-ribosylation. Addition of GTP potentiated, while GDP-beta S or PTX abolished, the effects of AII on BBM PLA and 22Na+ uptake, suggesting the involvement of G-protein in AII's actions. On the other hand, inhibition of PLA by mepacrine prevented AII's effect on BBM 22Na+ uptake, and activation of PLA by mellitin or addition of arachidonic acid similarly enhanced BBM 22Na+ uptake, suggesting the role of PLA activation in mediating AII's effect on BBM 22Na+ uptake. In summary, results of the present study show a direct stimulatory effect of AII on BBM Na+/H+ antiport system, and suggest the presence of a local signal transduction system involving G-protein mediated PLA activation.

• OSTI ID: 5162870
• Journal Information: Journal of Membrane Biology; (United States), Journal Name: Journal of Membrane Biology; (United States) Vol. 122:1; ISSN JMBBB; ISSN 0022-2631
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ALKALI METAL COMPOUNDS
ALKALI METAL ISOTOPES
ANGIOTENSIN
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-PLUS DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
BODY
CARBOXYLESTERASES
CARDIOVASCULAR AGENTS
CELL CONSTITUENTS
CELL MEMBRANES
DRUGS
ENZYME ACTIVITY
ENZYMES
ESTERASES
GLOBULINS
HYDROLASES
ISOMERIC TRANSITION ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
KIDNEYS
KINETICS
LIGHT NUCLEI
LIPASES
MAMMALS
MEMBRANE TRANSPORT
MEMBRANES
NANOSEC LIVING RADIOISOTOPES
NUCLEI
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
ORGANS
PROTEINS
RABBITS
RADIOISOTOPES
REACTION KINETICS
SODIUM 22
SODIUM COMPOUNDS
SODIUM ISOTOPES
TRACER TECHNIQUES
VASOCONSTRICTORS
VERTEBRATES
YEARS LIVING RADIOISOTOPES