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Biomedical subjects

B E Kolts

Publications and source records attributed to B E Kolts.

26 records · Page 2Linked to original sources
PubMed1983

Simultaneous pancreatic, gastric and hormonal responses to 2-deoxyglucose in the conscious pig.

The effect of vagal stimulation induced by 2-deoxy-D-glucose (2DG) on gastric acid and pancreatic bicarbonate output, and portal gastrin and secretin concentrations, was assessed in conscious miniature pigs. Electrical vagal stimulation has previously been shown to induce profuse pancreatic water and bicarbonate secretion in anaesthetized pigs. Pigs in this study were surgically prepared with gastric and pancreatic fistulas and indwelling jugular and portal catheters. An intravenous bolus of 2DG (100 mg/kg body weight) caused a significant increase in both gastric acid and pancreatic bicarbonate output although the latter was about 50% of the reported response to electrical vagal stimulation. Portal gastrin concentration rose significantly after 2DG, but the portal secretin concentration did not change. The presence of secretin in the small intestine was confirmed by intrajejunal HCl infusion. Failure of portal secretin concentration to rise after 2DG infusion rules against a role for this hormone in the pancreatic response.

Animals↗
PubMed1982

Secretin levels in plasma and tissue of the neonatal swine.

The mean fasting serum secretin level determined in newborn swine was found to be 298.0 +/- (SEM) 5 pg/ml, significantly higher than that in the adult animal. Intraduodenal infusion of 0.1 N HCl produced dramatic elevation of the mean serum secretin level to 2,090 +/- 340 pg/ml. The tissue secretin concentration of duodenal mucosa as well as the molecular species of tissue secretin were found to be identical to that of the adult swine. The mean disappearance half-life of exogenously administered secretin in the newborn swine was significantly prolonged over adult values, to 3.6 min. These data suggest that delayed secretin degradation can be implicated as a factor in the etiology of the hypersecretinemia in the newborn swine.

Animals↗
PubMed1982

Effect of secretin on gastric parietal cell ultrastructure in man.

The effect of secretin on parietal cell ultrastructure and on gastric mucosal potential difference have not been reported. In five healthy subjects, we studied the effect of intravenous injection of 2 clinical units per kg. of secretin on parietal cell canalicular and tubulovesicular membrane areas. In addition, we studied the effect of secretin on serum secretin levels and gastric mucosal potential difference. Biopsies of gastric mucosa for light and electron microscopy were obtained prior to and 15 and 30 minutes after secretin injection. Electron micrographs of 140 parietal cells were analyzed by the Loud quantitative method. Fifteen minutes following secretin administration, parietal cell canalicular membrane area decreased from a basal value of 4.37 +/- 0.43 per cent to 3.17 +/- 0.28 per cent (p less than 0.01). The number and length of microvilli also significantly decreased. Tubulovesicular membrane area increased from 9.32 +/- 0.7 per cent to 9.74 +/- 0.6 per cent (p greater than 0.05). The effect of secretin on canalicular membrane area was short lived, with recovery to nearly basal level at 30 minutes. Nuclear membrane area did not change at 15 and 30 minutes after secretin. After injection, serum secretin increased from a mean basal value of 15 to 2800 pg. per ml. at 15 minutes, falling to 130 pg. per ml. at 30 minutes. Gastric potential difference following secretin injection rose from -43 +/- 2 mv. to -54 +/- 2 mv. (p less than 0.01) within 10 minutes. In conclusion, a pharmacologic dose of secretin alters gastric parietal cell ultrastructure and causes significant elevation of gastric mucosal potential difference.

Adult↗
PubMed1977

Radioimmunoassay measurement of secretin half-life in man.

High titer antibodies to secretin were produced in rabbits by immunization with purified porcine secretin (from GIH) conjugated to bovine serum albumin in complete Freund's adjuvant. Synthetic porcine secretin (from Squibb) was radiolabeled with 125I using chloramine-T and radiosecretin was purified using talc-silica and fibrocellulose powder. Specificity of antibodies to secretin was extensively evaluated in studies examining (1) cross-reactivity with other naturally occurring hormones, (2) parellelism of serum dilutions and secretin standards, (3) quantitative recovery of secretin added to serum samples, and (4) changes in circulating immunoreactive secretin in response to intraduodenal acidification. The mean fasting serum secretin concentration in 10 dogs was 65 +/- 5 (SEM) pg per ml and in 21 healthy human volunteers it was 69 +/- 5 pg per ml. In response to intraduodenal instillation of 10 mEq of HCl, portal venous secretin concentrations increased from a mean fasting value of 52 to 450 pg per ml within 2 min; peripheral venous secretin increased from 66 to 229 pg per ml within 5 min. No significant changes in peripheral serum immunoreactive secretin concentrations were identified in dogs after a protein meal. Intravenously administered secretin in man disappeared from the circulation with mean half-life 4.06 +/- 0.82 (SEM) min.

Animals↗
PubMed1975

Serum gastrin and secretin levels after the Exalto-Mann-Williamson procedure.

The Exalto-Mann-Williamson procedure produces peptic ulceration in nearly 100% of experimental animals but the mechanism is unknown. To investigate the possible hormonal role of the gastric acid hypersecretion seen after this procedure, we investigated preoperative and postoperative serum gastrin and secretin concentrations. There was no significant change in serum gastrin; however, serum secretin concentrations increased to 2 1/2 times the preoperatve value, most likely secondary to the enhanced secretion of gastric acid. These data do not suppport the theory that alterations in circulating secretin or gastrin levels are responsible for the gastric acid hypersecretion following the Exalto-Mann-Williamson operation.

Animals↗