Somatostatin inhibits cANP-mediated cholinergic transmission in the myenteric plexus

Journal Article · Sat Oct 31 23:00:00 EST 1987 · American Journal of Physiology; (USA)

OSTI ID:7191814

Wiley, J; Owyang, C ^[1]

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1. Univ. of Michigan Medical School, Ann Arbor (USA)

The mechanism by which somatostatin acts to modulate cholinergic transmission is not clear. In this study the authors investigated the role of the adenosine 3{prime},5{prime}-cyclic monophosphate (cAMP) system in mediating cholinergic transmission in the guinea pig myenteric plexus and examined the ability of somatostatin to alter acetylcholine (ACh) release stimulated by various cAMP agonists. Forskolin, 8-bromo-cAMP, vasoactive intestinal peptide (VIP), and cholera toxin each stimulated the release of ({sup 3}H)ACh in a dose-related manner. Addition of theophylline enhanced the release of ({sup 3}H)ACh stimulated by these cAMP agonists. The observations suggest that cAMP may serve as a physiological mediator for ACh release from myenteric neurons. Somatostatin inhibited release of ({sup 3}H)ACh evoked by various cAMP agonists in a dose-related manner. Pretreatment with pertussis toxin antagonized the inhibitory effect of somatostatin on the release of ({sup 3}H)ACh evoked by forskolin, VIP, or cholera toxin but had no effect on the inhibitory action of somatostatin on the release of ({sup 3}H)ACh evoked by 8-bromo-cAMP. This suggests that the principal mechanism by which somatostatin inhibits cAMP-mediated cholinergic transmission is via activation of the inhibitory regulatory protein (N{sub i} subunit) of adenyalte cyclase.

• OSTI ID: 7191814
• Journal Information: American Journal of Physiology; (USA), Journal Name: American Journal of Physiology; (USA) Vol. 253:5; ISSN 0002-9513; ISSN AJPHA
• Country of Publication: United States
• Language: English

Related Subjects

551001* -- Physiological Systems-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ACETYLCHOLINE
AMINES
AMMONIUM COMPOUNDS
AMP
ANIMAL CELLS
ANIMALS
AUTONOMIC NERVOUS SYSTEM AGENTS
BIOLOGICAL EFFECTS
DOSE-RESPONSE RELATIONSHIPS
DRUGS
ESTERS
GUINEA PIGS
HYDROGEN COMPOUNDS
MAMMALS
MEMBRANE TRANSPORT
NERVE CELLS
NEUROREGULATORS
NUCLEOTIDES
ORGANIC COMPOUNDS
PARASYMPATHOMIMETICS
PHYSIOLOGY
QUATERNARY COMPOUNDS
RODENTS
SOMATIC CELLS
SOMATOSTATIN
TRITIUM COMPOUNDS
VERTEBRATES