Alpha-1 adrenergic receptor: Binding and phosphoinositide breakdown in human myometrium

Journal Article · Mon Jul 01 04:00:00 EDT 1991 · Journal of Pharmacology and Experimental Therapeutics; (United States)

OSTI ID:5394085

Breuiller-Fouche, M; Doualla-Bell Kotto Maka, F; Geny, B; Ferre, F ^[1]

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1. INSERM U.166 Groupe de recherches sur l'Endocrinologie de la Reproduction, Maternite Baudelocque, Paris (France)

Alpha-1 adrenergic receptors were examined in both inner and outer layers of human pregnant myometrium using radioligand binding of (3H)prazosin. (3H)prazosin bound rapidly and reversibly to a single class of high affinity binding sites in myometrial membrane preparations. Scatchard analysis gave similar values of equilibrium dissociation constants in both myometrial layers. In contrast, more alpha-1 adrenergic receptors were detected in the outer layer than in the inner layer. Antagonist inhibited (3H)prazosin binding with an order of potency of prazosin greater than phentolamine greater than idazoxan. Competition experiments have also revealed that a stable guanine nucleotide decreases the apparent affinity of norepinephrine for myometrial (3H)prazosin binding sites. The functional status of these alpha-1 adrenergic receptors was also assessed by measuring the norepinephrine-induced accumulation of inositol phosphates in myometrial tissue. Norepinephrine produced a concentration-dependent accumulation of inositol phosphates in both myometrial layers. However, norepinephrine-induced increases in inositol 1,4,5-triphosphate were only observed in the outer layer. These results indicate that alpha-1 adrenergic receptors in human myometrium at the end of pregnancy are linked to phosphoinositide hydrolysis and that this response occurs mainly in the outer layer.

• OSTI ID: 5394085
• Journal Information: Journal of Pharmacology and Experimental Therapeutics; (United States), Journal Name: Journal of Pharmacology and Experimental Therapeutics; (United States) Vol. 258:1; ISSN JPETA; ISSN 0022-3565
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ANIMALS
AUTONOMIC NERVOUS SYSTEM AGENTS
BIOCHEMICAL REACTION KINETICS
BODY
CELL CONSTITUENTS
CELL MEMBRANES
DOSE-RESPONSE RELATIONSHIPS
DRUGS
ESTERS
FEMALE GENITALS
FEMALES
HYDROGEN COMPOUNDS
ISOTOPE APPLICATIONS
KINETICS
LIPIDS
MAMMALS
MAN
MEMBRANE PROTEINS
MEMBRANES
METABOLISM
ORGANIC COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
ORGANS
PHOSPHOLIPIDS
PREGNANCY
PRIMATES
PROTEINS
REACTION KINETICS
RECEPTORS
SYMPATHOMIMETICS
TRACER TECHNIQUES
TRITIUM COMPOUNDS
UTERUS
VERTEBRATES
WOMEN