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Titolo:
Different affinity states of CCK1 receptors on pancreatic acini and gastric smooth muscle in the rat
Autore:
Kisfalvi, K; Racz, G; Zsirka-Klein, A; Pelosini, I; Scarpignato, C; Varga, G;
Indirizzi:
Hungarian Acad Sci, Inst Expt Med, H-1450 Budapest, Hungary Hungarian AcadSci Budapest Hungary H-1450 Med, H-1450 Budapest, Hungary Semmelweis Univ Med, Dept Med, H-1085 Budapest, Hungary Semmelweis Univ Med Budapest Hungary H-1085 ed, H-1085 Budapest, Hungary Semmelweis Univ Med, Dept Surg, H-1085 Budapest, Hungary Semmelweis Univ Med Budapest Hungary H-1085 rg, H-1085 Budapest, Hungary Semmelweis Univ Med, Dept Oral Biol, Budapest, Hungary Semmelweis Univ Med Budapest Hungary Dept Oral Biol, Budapest, Hungary Maggiore Univ Hosp, Lab Clin Pharmacol, Parma, Italy Maggiore Univ Hosp Parma Italy v Hosp, Lab Clin Pharmacol, Parma, Italy
Titolo Testata:
JOURNAL OF PHYSIOLOGY-PARIS
fascicolo: 1-6, volume: 95, anno: 2001,
pagine: 391 - 398
SICI:
0928-4257(200101/12)95:1-6<391:DASOCR>2.0.ZU;2-O
Fonte:
ISI
Lingua:
ENG
Soggetto:
CHOLECYSTOKININ-A RECEPTORS; MESSENGER-RNA EXPRESSION; GUINEA-PIG GALLBLADDER; GASTROINTESTINAL-TRACT; FUNCTIONAL EXPRESSION; GROWTH; ANTAGONIST; SECRETION; POTENT; SUBTYPES;
Keywords:
cholecystokinin; JMV-180; exocrine pancreas; amylase secretion; stomach; gastric smooth muscle; contraction; high affinity; low affinity; CCK-receptors;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
46
Recensione:
Indirizzi per estratti:
Indirizzo: Varga, G Hungarian Acad Sci, Inst Expt Med, POB 67, H-1450 Budapest, Hungary Hungarian Acad Sci POB 67 Budapest Hungary H-1450 apest, Hungary
Citazione:
K. Kisfalvi et al., "Different affinity states of CCK1 receptors on pancreatic acini and gastric smooth muscle in the rat", J PHYSL-PAR, 95(1-6), 2001, pp. 391-398

Abstract

It has recently been shown that-after chronic cholecystokinin (CCK) treatment-an adaptation of pancreatic secretory but not gastric motor function does occur. Recent studies indicate that the CCK1-receptor exists in two (i.e. high and low) affinity states, which could be distinguished by the CCK-analogue JMV-180. CCK occupancy of high and low affinity sites is thought to be related to the initiation of different intracellular events and consequent biological responses. Affinity states of CCK1-receptors on pancreas and gastrointestinal (GI) smooth muscle could be different and this can offer an explanation for the different effects of CCK on pancreatic and gastric growth. We therefore studied the affinity states of CCK1-receptors on isolated rat pancreatic acini and gastric smooth muscle preparations. When acini were incubated with increasing concentrations of CCK-8, a biphasic (i.e. stimulation followed by inhibition) effect on amylase release was observed. JMV-180 caused only stimulation of enzyme release and combined JMV-180 and CCK stimulation (at submaximal doses) resulted in an additive secretory response. CCK-8 induced contractions of pyloric, antral and fundic muscle in a concentration-dependent manner. The response was monophasic, reaching a plateau. JMV-180 had only a very weak effect on these preparations. On the contrary, it inhibited CCK-induced contractions in a competitive manner, the concentration-response curve to CCK being shifted to the right by the CCK analogue. Our data suggest that the affinity states of CCK1-receptors on rat pancreatic and gastric tissue are different. On pancreatic acini CCK1-receptors exist in both high- and low-affinity states whose occupation is followed by the sequence of intracellular events leading to growth. In contrast, occupation of low affinity receptors (the only ones present in the GI smoothmuscle) does not lead to cell proliferation. This difference therefore explains the different adaptive response of the pancreas and the stomach to chronic CCK administration. Furthermore, different affinity states of CCK1-receptors may mediate different functions of the digestive tract. (C) 2001 Elsevier Science Ltd. All rights reserved.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 25/01/20 alle ore 03:50:05