Roxburgh, James Cathcart;
(1990)
The acute and chronic effects of cigarette smoking upon various aspects of gastric secretion.
Masters thesis (M.S), UCL (University College London).
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Abstract
This study examined the inter-relationship between cigarette smoking (acute and chronic) on the one hand and gastric acid secretion, duodenogastric reflux and pyloric loss on the other. Using gastric intubation and a histamine secretogogue, pure gastric secretion (Vg), pyloric loss (PL) and duodenogastric reflux (DGR) were measured in smokers and non-smokers with and without duodenal ulcer disease. The subjects were studied at basal, 1/8th maximal, 1/4 maximal and maximal stimulation. Acute cigarette smoking significantly reduced Vg in both controls (C) (n = 8) and duodenal ulcer subjects (DU) (n = 14); there was no change in either pyloric loss or duodenogastric reflux. The fall in Vg coincided with the period in which there is known to be a rise in the plasma levels of toxic tobacco products. In both groups of chronic smokers (C, n = 68; DU, n = 177) maximal Vg was significantly greater than in non-smokers (C, n = 46; DU, n = 36). Under basal conditions Vg was lower in the smokers (C, n = 25; DU, n = 91) compared to non-smokers (C, n = 20; DU, n = 15) but this did not reach significance. The rate of pyloric loss was constant in any one individual, independent of secretory or clinical state. However, pyloric loss was higher in those with a greater secretory capacity: namely, smokers and duodenal ulcer patients. Duodenogastric reflux was greatest under basal conditions and significantly reduced at maximal stimulation, this was true for both groups (C & DU). This was thought to represent increased activity of the pylorus under conditions of maximal stimulation. Duodenogastric reflux was greater in those with duodenal ulcers compared to controls at both basal and maximal secretion. Analysis showed that this difference may in part reflect the disease process. Chronic cigarette smoking had no direct effect on pyloric loss or duodenogastric reflux, any effect there was, was mediated through changes in secretory capacity. Dose-response analysis revealed no evidence of increased sensitivity of the parietal cells in either duodenal ulcer patients or chronic smokers. The increased secretory capacities of these groups is simply due to an increased parietal cell mass. It is suggested that the toxic products of tobacco smoke cause an acute reduction in Vg which eventually leads to an increase in parietal cell mass and hence Vg.
Type: | Thesis (Masters) |
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Qualification: | M.S |
Title: | The acute and chronic effects of cigarette smoking upon various aspects of gastric secretion |
Open access status: | An open access version is available from UCL Discovery |
Language: | English |
Additional information: | Thesis digitised by ProQuest. |
Keywords: | Health and environmental sciences |
URI: | https://discovery.ucl.ac.uk/id/eprint/10121182 |
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