Agonist-induced activation of rat mesenteric resistance vessels: comparison between noradrenaline and vasopressin

Journal Article · Fri Jan 01 04:00:00 EST 1988 · J. Cardiovasc. Pharmacol.; (United States)

DOI:https://doi.org/10.1097/00005344-198800125-00023· OSTI ID:5965165

Cauvin, C; Weir, S W; Wallnoefer, A R; Rueegg, U P

The effects of noradrenaline (NA, 10(-5) M) and (arginine8)vasopressin (AVP, 10(-7) M) on tension in Ca2+-free medium and on membrane potential, and the inhibition of NA- and AVP-induced contractions by isradipine, have been compared in mesenteric resistance vessels (MRVs) from Wistar-Kyoto (WKY) rats. The release of intracellular Ca2+ by AVP contributed significantly less to its tension development than does that by NA. Nonetheless, the concentration-response curves for inhibition by isradipine of NA- and AVP-induced tonic tension were nearly identical. Similarly, these two agonists produced the same degree of membrane depolarization. In addition, both agonists were able to stimulate large contractions in vessels previously depolarized by 80 mM K+. AVP also stimulated /sup 45/Ca influx into rat cultured aortic smooth muscle cells. In contrast to the stimulation of /sup 45/Ca influx by KCl depolarization, the agonist-stimulated /sup 45/Ca influx was insensitive to inhibition by organic Ca2+ antagonists. It is concluded that Ca2+ entry through receptor-operated Ca2+-permeable channels (ROCs) may contribute to agonist-induced activation of rat aortic and MRV smooth muscle.

• Research Organization: Preclinical Research, Sandoz Ltd., Basel (Switzerland)
• OSTI ID: 5965165
• Journal Information: J. Cardiovasc. Pharmacol.; (United States), Journal Name: J. Cardiovasc. Pharmacol.; (United States); ISSN JCPCD
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ADRENAL HORMONES
ALKALINE EARTH ISOTOPES
ALKALINE EARTH METAL COMPOUNDS
ANIMALS
AUTONOMIC NERVOUS SYSTEM AGENTS
AZINES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
CALCIUM 45
CALCIUM COMPOUNDS
CALCIUM ISOTOPES
CARDIOTONICS
CARDIOVASCULAR AGENTS
CELL CONSTITUENTS
CELL CULTURES
CELL MEMBRANES
COMPARATIVE EVALUATIONS
CONTRACTION
DAYS LIVING RADIOISOTOPES
DOSE-RESPONSE RELATIONSHIPS
DRUGS
EVEN-ODD NUCLEI
HETEROCYCLIC COMPOUNDS
HORMONES
INTERMEDIATE MASS NUCLEI
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
MAMMALS
MEMBRANE TRANSPORT
MEMBRANES
MUSCLES
NEUROREGULATORS
NORADRENALINE
NUCLEI
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PEPTIDE HORMONES
PITUITARY HORMONES
PYRIDINES
RADIOISOTOPES
RATS
REACTION KINETICS
RODENTS
SYMPATHOMIMETICS
TRACER TECHNIQUES
VASOPRESSIN
VERTEBRATES