Gastrin receptors on isolated canine parietal cells.

“…With regard to the model of guanine-nucleotide-binding regulatory protein(s)-linked receptor, this strongly suggests that the sulfate group on the tyrosyl residue of CCK is required to promote the high-affinity state of the CCK receptor and/or formation of the ternary complex. It is worth remembering that such a structural requirement for agonist activity through pancreatic A-subtype CCK receptor is of much less importance for other pharmacological types of this receptor such as pancreatic [33], central [7] and gastric [34] B-subtypes. Further investigations should elucidate how the sulfate group on the tyrosyl residue of CCK is so crucial in promoting an active state of the A-subtype receptor whereas it is not for the B-subtypes.…”

Section: Discussionmentioning

confidence: 99%

Study of the states and populations of the rat pancreatic cholecystokinin receptor using the full peptide antagonist JMV 179

Silvente-Poirot

Hadjiivanova

Escrieut

et al. 1993

European Journal of Biochemistry

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The full peptide antagonist of the pancreatic cholecystokinin (CCK) receptor, JMV 179, [BocTyr(S0,H)-Ahx-Gly-dTrp-Ahx-Asp phenylethyl ester, where Tyr(S0,H) = sulfated tyrosine, Ahx = 6-aminohexanoic acid] was modified at its N-terminus by incorporation of p-hydroxyphenyl propionate (Bolton-Hunter reagent, BH) and was subsequently radioiodinated. After HPLC purification, lZ51-BH-JMV-179, a CCK antagonist radioligand of high specific activity (2000 CUmmol) was obtained. '251-BH-JMV-179 bound to a single population of sites on rat pancreatic plasma membranes, (K, = 3.9 nM, B,,, = 40 pmoVmg protein). Binding was dependent on time, temperature, and protein concentration, and was fully reversible. JMV 179 radioligand detected four times as many sites This study, with the first CCK peptide antagonist radioligand, demonstrates that CCK receptors exist in two interconvertible affhity states regulated by guanine-nucleotide-binding regulatory protein(s) in rat pancreatic plasma membranes. JMV 179 radioligand does not induce receptor coupling but distinguishes the two affinity states of the CCK receptors. JMV 179 reveals the existence of populations of high-affinity and low-affinity sites for CCK which had not previously been detected by agonist radioligand binding, thus suggesting heterogeneity of CCK receptor sites in membranes.Studies during the last decade have abundantly documented the wide distribution of cholecystokinin (CCK) peptides within the gastrointestinal tract as well as the nervous system [l]. Pancreatic acinar cells from rat possess only Asubtype CCK receptors [2-41, the occupation of which by CCK agonists stimulates enzyme exocytosis [ 5 ] . The recent cloning and sequencing of the CCK receptor cDNA has provided important information [6]. However, many questions

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“…In addition to the morphological characteristics, the surface mucous cells exhibit specific biochemical characteristics with periodic acid Schiff (PAS) 1 staining: synthesis and secretion of the two major components, macromolecular mucin and surfaceactive phospholipids (3,4). With the morphological feature of secretory granules and the biochemical characteristic of PASpositive staining, the cells are distinct from other mucosal cell subtypes such as parietal cells and chief cells (4,5).…”

Section: Introductionmentioning

confidence: 99%

Proprotein-processing endoprotease furin controls the growth and differentiation of gastric surface mucous cells.

Konda

Yokota²,

Kayo³

et al. 1997

J. Clin. Invest.

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Gastric surface mucous cells originate from progenitor cells at the isthmus of the gastric gland, from where the cells migrate to the luminal surface. With migration they form secretory granules and express TGF ␣ . We found that proprotein-processing endoprotease furin-positive cells were layered around the upper one fourth of the gastric glands of adult rats, whereas they were distributed along an outer epithelial layer in fetal rats. Because the furin-positive cell layer was localized from the upper cell proliferating zone to the less proliferating pit-cell region in the gastric gland unit, we ex-

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Gastrin receptors on isolated canine parietal cells.

Abstract: Abstract. The receptors in the fundic mucosa that mediate gastrin stimulation of acid secretion have been studied. Synthetic human gastrin-17-I (G17) with a leucine substitution in the 15th position ([Leu'5]

Cited by 222 publications

References 42 publications

Detection of Cholecystokinin B/Gastrin Receptor mRNA Expressing Cells in the Stomach of Hypergastrinemic Rats.

Detection of Cholecystokinin B/Gastrin Receptor mRNA Expressing Cells in the Stomach of Hypergastrinemic Rats.

Study of the states and populations of the rat pancreatic cholecystokinin receptor using the full peptide antagonist JMV 179

Proprotein-processing endoprotease furin controls the growth and differentiation of gastric surface mucous cells.

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