Effect of Metiamide on Acid Secretion from Isolated Kitten Fundic Mucosa

1975 ◽  
Vol 53 (6) ◽  
pp. 1141-1146 ◽  
Author(s):  
B. L. Tepperman ◽  
B. Schofield ◽  
F. S. Tepperman

Isolated kitten fundic mucosa demonstrates low rates of spontaneous acid secretion in vitro when bathed in Krebs–Henseleit solution, and responds consistently to histamine, pentagastrin, and acetylcholine placed in the bath. High rates of spontaneous secretion or secretion in response to histamine and pentagastrin were significantly inhibited by addition of metiamide (5 × 10−3 M); but mucosa stimulated by constant addition of acetylcholine chloride (10−4 M) was not inhibited by metiamide at the same concentration.

2005 ◽  
Vol 521 (1-3) ◽  
pp. 139-143 ◽  
Author(s):  
Francesca Borrelli ◽  
Inmaculada Posadas ◽  
Raffaele Capasso ◽  
Gabriella Aviello ◽  
Valeria Ascione ◽  
...  

1982 ◽  
Vol 242 (1) ◽  
pp. G21-G26 ◽  
Author(s):  
R. A. Levine ◽  
K. R. Kohen ◽  
E. H. Schwartzel ◽  
C. E. Ramsay

Relations among cAMP, cGMP, acid production [measured by the intraglandular accumulation of [14C]aminopyrine (AP)], and prostaglandin E2 (PGE2) activity were studied in isolated glands from rabbit fundic mucosa. AP, cAMP, and cGMP responses to histamine, PGE2, and 3-isobutyl-1-methylxanthine (IMX) were compared with controls. Histamine and PGE2 significantly increased glandular cAMP levels twofold, and histamine and IMX stimulated AP uptake two- to fourfold. PGE2 significantly inhibited both histamine- and IMX-stimulated AP accumulation, but it did not alter basal AP uptake. PGE2 also decreased histamine-stimulated cAMP production but only at a low concentration (10(-7) M). This dose of PGE2 was near to the endogenous PGE2 content found in unstimulated glands (10(-8) M). Intraglandular cGMP levels in unstimulated glands (10(-8) M). Intraglandular cGMP levels were increased by IMX but not by PGE2 or histamine. It is concluded that histamine stimulation of acid secretion is mediated by cAMP, that secretory and biochemical responses to histamine are modulated by PGE2 because PGE2 antagonized histamine-stimulated cAMP and AP uptake, and that the rise in cAMP induced solely by PGE2 appears to be localized within nonparietal cells because PGE2 alone did not stimulate AP accumulation.


2003 ◽  
Vol 284 (1) ◽  
pp. G145-G153 ◽  
Author(s):  
Karen L. Hinkle ◽  
Gina C. Bane ◽  
Ali Jazayeri ◽  
Linda C. Samuelson

Gastrin-deficient mice have impaired basal and agonist-stimulated gastric acid secretion. To analyze whether an intrinsic parietal cell defect contributed to the reduced acid secretion, we analyzed parietal cell calcium responses and acid secretory function in vitro. Parietal cells were purified by light-scatter cell sorting and calcium responses to gastrin, histamine, and carbachol were measured in gastrin-deficient and wild-type mice cell preparations. Surprisingly, basal and histamine-induced calcium concentrations were higher in the mutant cell preparations. [14C]aminopyrine uptake analysis in acutely isolated gastric glands revealed that basal acid accumulation was enhanced in gastrin-deficient cell preparations as well as on treatment with carbachol or histamine. These results suggested that an intrinsic parietal cell defect was not responsible for the reduced acid secretion in gastrin-deficient mice. Flow cytometric analysis of dispersed, H+-K+-ATPase-immunostained gastric mucosal preparations revealed a marked increase in parietal cell number in gastrin-deficient mice, which may have accounted for the enhanced in vitro acid secretion detected in this study. Parietal cells were found to be significantly smaller in the mutant cell preparations, suggesting that gastrin stimulation modulates parietal cell morphology.


1974 ◽  
Vol 226 (4) ◽  
pp. 898-902 ◽  
Author(s):  
RL Shoemaker ◽  
E Buckner ◽  
JG Spenney ◽  
G Sachs

1997 ◽  
Vol 273 (6) ◽  
pp. F857-F868 ◽  
Author(s):  
Susan M. Wall

In the rat terminal inner medullary collecting duct (tIMCD), Na+ pump inhibition reduces transepithelial net acid secretion ( J tAMM) [ J H = total CO2 absorption ( J tCO2) + total ammonia secretion] and increases resting intracellular pH (pHi). The increase in pHi and reduction in J H that follow ouabain addition do not occur in the absence of[Formula: see text] nor when [Formula: see text]is substituted with another weak base. The purpose of this study was to explore the mechanism of the [Formula: see text]-dependent reduction in J tCO2 and increase in pHi that follow ouabain addition. We hypothesized that [Formula: see text]enters the tIMCD cell through the Na+-K+-ATPase with proton release in the cytosol. To test this hypothesis, tIMCDs were dissected from deoxycorticosterone-treated rats and perfused in vitro with symmetrical physiological saline solutions containing 6 mM NH4Cl. Since K+ and[Formula: see text] compete for a common binding site on the Na+ pump, increasing extracellular K+ should limit[Formula: see text] (and hence net H+) uptake by the Na+ pump. Upon increasing extracellular K+ concentration from 3 to 12 mM, the [Formula: see text]-dependent, ouabain-induced increase in pHiand reduction in J tCO2 were attenuated. In the presence but not in the absence of[Formula: see text], reducing Na+ pump activity by limiting Na+ entry reduced J tCO2 and attenuated ouabain-induced alkalinization. Ouabain-induced alkalinization was not dependent on the presence of[Formula: see text]/CO2and was not reproduced with BaCl2or bumetanide addition. Therefore, ouabain-induced alkalinization is not mediated by the Na+-K+-2Cl−cotransporter or a [Formula: see text] transporter and is not mediated by changes in membrane potential. In conclusion, on the basolateral membrane of the tIMCD cell,[Formula: see text] uptake is mediated by the Na+-K+-ATPase. These data provide an explanation for the reduction in net acid secretion in the tIMCD observed following administration of amiloride or with dietary K+ loading.


1984 ◽  
Vol 246 (3) ◽  
pp. G296-G304
Author(s):  
S. R. Vigna

Radioimmunoassay, radioreceptor assays, and bioassays were used to demonstrate that chicken brain and antrum extracts contain cholecystokinin (CCK)-like and gastrinlike peptides, respectively. C-terminal-specific radioimmunoassay of partially purified chicken CCK and gastrin gave dilution curves parallel to those of the mammalian peptides. Mouse cerebral cortical and rat pancreatic membrane radioreceptor assays were used to differentiate CCK- from gastrinlike peptides on the basis of the different CCK versus gastrin specificities of the two receptors. Confirmation of the biological activity of chicken brain CCK was obtained by stimulation of amylase secretion from rat pancreatic lobules in vitro. The specificity of this response was demonstrated by the inhibition of chicken CCK-stimulated amylase secretion by the specific CCK receptor antagonist dibutyryl cGMP. Chicken antral gastrin stimulated gastric acid secretion from the rat stomach in vivo. In contrast to previous hypotheses, it is proposed that chickens have significant amounts of an antral gastrinlike peptide and that therefore it is possible that gastrin is involved in the physiological regulation of gastric acid secretion in chickens.


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