Short-term cholinergic desensitization of rat pancreatic secretory response

Journal Article · Sun Mar 01 04:00:00 EST 1987 · Am. J. Physiol.; (United States)

OSTI ID:5353748

Asselin, J; Larose, L; Morisset, J

Dispersed pancreatic acini were first exposed to carbamylcholine (10/sup -7/-10/sup -4/ M) for 60 min, washed, and reexposed to this same agonist (10/sup -8/-10/sup -3/ M) for 15 min. During this second incubation, the functional secretory capacity of these acini was evaluated by measuring amylase release. Acini preexposed to concentrations of carbamylcholine of 10/sup -6/ M or greater showed shifts to the right in the subsequent carbamylcholine dose-response curves of amylase release. A 3-h recovery period (without carbamylcholine) did not restore the altered carbamylcholine dose-response curve. Ca/sup 2 +/ concentrations of 10/sup -7/ M or 2.5 x 10/sup -3/ M instead of 0.5 x 10/sup -3/ M during the 60-min preincubation did not affect the desensitization process. With use of N-(/sup 3/H)methylscopolamine to evaluate muscarinic receptors, the only changes observed after desensitization were a significant decrease in the high-affinity and an equivalent increase in that of the low-affinity receptors. After cholinergic exposure amylase release stimulated by caerulein was only slightly modified, whereas amylase release in response to a phorbol ester 12-O-tetradecanoylphorbol-13-acetate and to the ionophore A23187 was not altered. These data indicate that short-term desensitization with a cholinergic agent is relatively specific to muscarinic agonists, causes changes in the muscarinic receptor high-and low-affinity concentration but does not alter intracellular steps after calcium mobilization or protein kinase C activation known to be involved in the secretion process.

• Research Organization: Universite de Sherbrooke, Quebec
• OSTI ID: 5353748
• Journal Information: Am. J. Physiol.; (United States), Journal Name: Am. J. Physiol.; (United States) Vol. 252:3; ISSN AJPHA
• Country of Publication: United States
• Language: English

Related Subjects

550601* -- Medicine-- Unsealed Radionuclides in Diagnostics
62 RADIOLOGY AND NUCLEAR MEDICINE
ALCOHOLS
AMINES
AMMONIUM COMPOUNDS
AMYLASE
ANIMALS
BIOLOGICAL EFFECTS
BODY
CARCINOGENS
CHOLINE
DIGESTIVE SYSTEM
DRUGS
ENDOCRINE GLANDS
ENZYMES
ESTERS
GLANDS
GLYCOSYL HYDROLASES
HYDROLASES
HYDROXY COMPOUNDS
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
LIPOTROPIC FACTORS
MAMMALS
O-GLYCOSYL HYDROLASES
ORGANIC COMPOUNDS
ORGANS
PANCREAS
PHORBOL ESTERS
QUATERNARY COMPOUNDS
RADIORECEPTOR ASSAY
RATS
RODENTS
SECRETION
TRACER TECHNIQUES
TRITIUM COMPOUNDS
VERTEBRATES