D-2 dopamine receptor activation reduces free ( sup 3 H)arachidonate release induced by hypophysiotropic peptides in anterior pituitary cells

Journal Article · Fri Sep 01 00:00:00 EDT 1989 · Endocrinology; (USA)

DOI:https://doi.org/10.1210/endo-125-3-1180· OSTI ID:5547367

Canonico, P L ^[1]

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1. Univ. of Catania School of Medicine (Italy)

Dopamine reduces the stimulation of intracellular ({sup 3}H)arachidonate release produced by the two PRL-stimulating peptides angiotensin-II and TRH. This effect is concentration dependent and is mediated by stimulation of D-2 dopamine receptors. D-2 receptor agonists (bromocriptine, dihydroergocryptine, and dihydroergocristine) inhibit the release of fatty acid induced by angiotensin-II with a potency that parallels their ability to inhibit PRL release in vitro. Conversely, the selective D-2 receptor antagonist L-sulpiride completely prevents dopamine's effect, whereas SCH 23390 (a D-1 receptor antagonist) is ineffective. The inhibitory action of dopamine does not seem to be consequent to an action on the adenylate cyclase-cAMP system, as 8-bromo-cAMP (1 mM) does not affect either basal or dopamine-inhibited ({sup 3}H)arachidonate release. However, a 24-h pertussis toxin pretreatment significantly reduces the action of dopamine on fatty acid release. Collectively, these results suggest that D-2 dopamine receptor-mediated inhibition of intracellular ({sup 3}H)arachidonate release requires the action of a GTP-binding protein, but is not a consequence of an inhibitory action on cAMP levels.

• OSTI ID: 5547367
• Journal Information: Endocrinology; (USA), Vol. 125:3; ISSN 0013-7227
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
ARACHIDONIC ACID
SECRETION
DOPAMINE
RECEPTORS
PEPTIDES
BIOCHEMICAL REACTION KINETICS
ANGIOTENSIN
CELL CULTURES
INHIBITION
LTH
PITUITARY GLAND
RATS
SYMPATHOLYTICS
TOXINS
TRACER TECHNIQUES
TRITIUM COMPOUNDS
AMINES
ANIMALS
ANTIGENS
AROMATICS
AUTONOMIC NERVOUS SYSTEM AGENTS
BODY
CARBOXYLIC ACIDS
CARDIOTONICS
CARDIOVASCULAR AGENTS
DRUGS
ENDOCRINE GLANDS
GLANDS
GLOBULINS
GONADOTROPINS
HORMONES
HYDROGEN COMPOUNDS
HYDROXY COMPOUNDS
ISOTOPE APPLICATIONS
KINETICS
MAMMALS
MATERIALS
MEMBRANE PROTEINS
MONOCARBOXYLIC ACIDS
NEUROREGULATORS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANS
PEPTIDE HORMONES
PHENOLS
PITUITARY HORMONES
POLYPHENOLS
PROTEINS
REACTION KINETICS
RODENTS
SYMPATHOMIMETICS
TOXIC MATERIALS
VASOCONSTRICTORS
VERTEBRATES
550201* - Biochemistry- Tracer Techniques