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Biomedical subjects

S Raptis

Publications and source records attributed to S Raptis.

At least 181 records · Page 10Linked to original sources
PubMed1976

A reliable method for generating antibodies against pancreozymin, secretin and gastrin.

High specific antibodies against the gastrointestinal hormones pancreozymin, secretin, and gastrin were generated by coupling these peptides with N,N'-carbonyldiimidazole to bovine serum albumin. None of the antisera showed any cross reaction with gut and pancreatic hormones tested for cross reactivity. The dilution of antisera which were useful for the detection of 5-250 pg of hormone in human serum were 1:150 000 for secretin, 1:2000 for gastrin, and 1:2000 for pancreozymin. The N,N'-carbonyldiimidazole reagent is therefore highly effective for binding labile peptides to protein carriers without destroying the immunogenic features.

Antibody Formation↗
PubMed1976

Effects of somatostatin on exocrine and endocrine pancreatic function stimulated by intestinal hormones in man.

To evaluate the action of somatostatin on exocrine and endocrine pancreatic function, synthetic somatostatin (GIF) was administered (intravenous bolus of 300 mug followed by a constant 60-minute infusion, 5 mug/min) to 17 normal subjects. The secretin-induced volume and total bicarbonate contents of the duodenal aspirate were not affected whereas the bicarbonate concentration was significantly diminished. GIF reduced decisively the pancreatic enzyme secretion stimulated by pure (99%) cholecystokinin-pancreozymin. After the GIF infusion was stopped, a significant rise in enzyme secretion was observed. The secretin-induced insulin release was almost completely suppressed. Because GIF can be extracted in large quantities from pancreas, these data suggest that somatostatin may play a physiological role in the regulation of the secretory processes of this organ. Furthermore, GIF may be a useful adjunct in the treatment of acute pancreatitis.

Bicarbonates↗
PubMed1976

[Influence of somatostatin (GIF) and human gastrin I on the lower esophageal sphincter].

The influence of gastrin and somatostatin on the lower esophageal sphincter was investigated in 10 metabolically healthy volunteers and one patient with Zollinger-Ellison syndrome. It could be shown that only unphysiologically high concentrations of gastrin produced a rise in pressure in the lower esophageal sphincter, while somatostatin has neither an effect on the lower esophageal sphincter pressure, nor is it able to inhibit the pharmacologic effect of exogeneous gastrin administration. The results emphasize that gastrin and somatostatin have no influence on the tone of the lower esophageal sphincter.

Esophagogastric Junction↗
PubMed1976

Hypoglycemia in diabetics.

Hypoglycemia in diabetes can be divided into 1) spontaneous hypoglycemic reactions due to absolute or relative overproduction of endogenous insulin or some other blood glucose-lowering substance, as in islet cell adenoma or carcinoma, latent or protodiabetic conditions, (extrapancreatic) tumors and pituitary and/or adrenal disorders; and 2) hypoglycemia caused by exogenous, i.e. therapeutic, measures. The problem of hypoglycemia in insulin-treated diabetics is far from being solved. As revealed by continuous blood glucose monitoring, nocturnal hypoglycemic attacks frequently escape attention especially in juvenile diabetics. Circadian variations in peripheral glucose utilization, rather than changes in plasma insulin activity, are likely to be involved in this mechanism. At least, this was the conclusion drawn from studies carried out by means of a glucose-controlled insulin and glucose infusion system (GCIGIS) -or artificial pancreas-which delivers short-acting insulin and glucose on demand intravenously. Hypoglycemic reactions in patients being treated with oral anti-diabetic agents, on the other hand, should be regarded primarily as one of the side reactions intrinsic to the mechanism of action of some of these drugs, e.g. sulfonylureas, which act mainly via stimulation of secretion of endogenous insulin reserves not responding properly to postprandial blood glucose increments. In the case of glibenclamide, at least partial resensitization of the defective glucose receptor of the beta-cell also becomes operative. A higher incidence of a characteristic type of hypoglycemic reaction was observed soon after glibenclamide therapy was introduced. Better understanding of the drug and dissemination of the information about it to doctors and patients has reduced the number of hypoglycemic reactions caused by glibenclamide to the same proportions as for other sulfonylureas. Hypoglyoemia following therapeutic hypophysectomy retains its position as one of the main hazards of this heroic therapy.

Adenoma, Islet Cell↗
PubMed1976

[Interaction between gastrointestinal hormones and endocrine regulation].

The vicinity of several hormone-producing glands as part of the anatomy of the intestinal tract and the resulting interaction has been confirmed by the discovery of hormonal factors of a specifically gastro-intestinal origin. Today we are mainly interested in the interaction between intermediary metabolism and incretory intestinal function; this is characterized by the joint action of conventional glandular hormones such as insulin and pancreatic glucagon as well as by the incretion of diffuse intestinal organs, hormones such as secretin, pancreozymin, motilin, VIP and GIP. The latter are at present subject of active research with the object of discovering their physiological significance be it as tissue hormones or as humoral agents with a "long distance" impact; their role within pathophysiology is also of interest. GIP ("gastric inhibitory peptide"), apart form acting upon the intestinal tract, also causes a marked rise in insulin production; this GIP possibly is the factor responsible for the difference in glucose tolerance following i. v. or oral administration of glucose, something that scientists have been trying to discover for a long time. We have also endeavored to investigate somatostatin. This substance was originally discovered as a hypothalamic factor with inhibitory action on growth hormone secretion; in the meantime, however, cells containing and possibly also producing somatostatin have also been detected in the intestine and particularly in the islets of Langerhans (D-cells). Since somatostatin inhibits insulin secretion and especially glucagon release as well as the exretory functions of the stomach and of the pancreas, the significance of this hormone possibly is that of a tissue hormone with inhibitory action on adjacent cells. As factor inhibiting both endocrine and exocrine secretory processes it would combine these two complexes. The possible therapeutic significance of somatostatin administration to diabetics would lie in the saving of insulin. A third sector of present-day research deals with the interaction between the calcium metabolism and the hormones involved as well as the intestine. We know that patients suffering from primary hyperparathyroidism are prone to contract stomach ulcers and pancreatitis; patients with a gastrinoma and a hyperfunction of the epithelial bodies suffer from a Zollinger-Ellison-sindrome and this again suggests association with endocrine polyadenomatosis (Wermer syndrome). The inhibitory action of the parathormone antagonist calcitonin on the exocrine functions of the intestinal tract, such as the acid secretion of the stomach and the enzyme secretion of the pancreas, have already given rise to some considerations and experiments relative to treatment. It is to be hoped that because of all the joint observations cited above there will be better intergration of research both from the aspect of gastro-enterology and endocrinology. This might hopefully elucidate some of the unresolved problems ranging from basic research to practical application.

Adolescent↗
PubMed1976

Gastrin concentration in plasma of the neonate at birth and after the first feeding.

Plasma gastrin was determined simultaneously in 19 newborn infants and their respective mothers shortly after birth and in ten neonates before and after the first feeding. The gastrin concentrations in the umbilical vein plasma of the newborn infants were significantly higher than in the peripheral vein plasma of their mothers. The values were statistically not different from those obtained in the neonates before the first feeding. There was an increase in gastrin concentrations after the first feeding. From these results it is suggested that gastrin is produced in the neonate independently from the mother. It is already secreted after the first feeding. Experiments in rats showed that 125I-gastrin is not transported through the placenta. From these findings we assume that most likely the gastrin measured in plasma of newborn infants is of neonatal origin.

Adult↗
PubMed1975

Effect of lipids on insulin, growth hormone and exocrine pancreatic secretion in man.

Influences of fat on release of insulin, growth hormone and pancreatic enzyme secretion were studied in 35 metabolically healthy subjects. A fat solution containing 40 g of soy bean oil was administered, I.V., orally and intraduodenally. In all cases there was a similar increase of insulin but the rise in serum insulin after oral or intraduodenal fat administration was not related to the changes in plasma free fatty acids, free glycerol and triglyceride levels. Blood surgar responded according to insulin secretion. The route of fat administration may possibly influence growth hormone secretion. Following intraduodenal fat administration volume and bicarbonate contents of the duodenal juice rose slightly whereas trypsin and bilirubin content increased considerably. These results suggest that insulin secretion after oral or intraduodenal administration of fat is influenced by intestinal factors. Cholecystokinin-pancroezymin and gastric inhibitory polypeptide are qualified to serve as such factors.

Blood Glucose↗
PubMed1975

[Continuous daily blood-sugar profile in relation to serum insulin in subjects with normal metabolism and ideal or normal weight (author's transl)].

Continuous blood-sugar measurement is at present the most suitable method for testing daily blood sugar profile. It allows to relate variations in blood sugar levels in metabolically normal subjects to body weight. Mean blood-sugar level and postprandial blood-sugar variations are greater in those of normal than of ideal weight. At the same time, metabolically normal subjects of normal weight have a high insulin secretion in the fasting and postprandial states. This makes it likely that those of normal weight, although it is only slightly different from those of ideal weight, have already reached a transitional stage to an increased diabetes risk from over-weight.

Blood Glucose↗
PubMed1975

Extended somatostatin treatment of a patient with bleeding ulcer.

The results of a 67 hour cyclic somatostatin continuous infusion in a patient with a bleeding ulcer are reported. The subject was a 65 year old male with very heavy gastrointestinal bleeding on the 9th postoperative day following a high BI-resection. Endoscopy revealed the bleeding to be caused by two residual ulcers in the area of the anastomosis. Somatostatin treatment led to an immediate cessation of the bleeding after 1 hour. Gastric secretion as well as gastrin, insulin and growth hormone levels were significantly inhibited by somatostatin. Endoscopy at the end of the treatment period showed two ulcers in the process of healing. The raised blood glucose levels caused by somatostatin were easily controlled with max. 14 IU cristalline insulin daily. Except for dryness in the mouth, no adverse side effects were apparent. There was no evidence from laboratory investigations of hemostatic defects or bleeding tendency in the patient.

Aged↗
PubMed1975

Effects of secretin and cholecystokinin on motor activity of human jejunum. A radiotelemetering study of jejunal motility during secretin and cholecystokinin intravenous infusion.

The effects of intravenous administration of secretin and cholecystokinin (CCK) on motility of the human jejunum were investigated with pressure-sensitive radiotelemetering capsules. Secretin inhibited and CCK stimulated the spontaneous motor activity of this part of the small intestine. Raising the dosages of the two hormones caused increasing effects. It seems likely, therefore, that both hormones play a role in the regulation of intestinal motility in man.

Adult↗
PubMed1975

Effects of somatostatin on gastric secretion and gastrin release in man.

Somatostatin, a recently synthesized hypothalamic growth hormone release-inhibiting factor (GIF), was used in the cyclic and linear form. In all subjects studied, the cyclic GIF inhibited gastrin secretion during basal conditions as well as during a standard food stimulus, with immediate rebound after the infusion was stopped. Similar responses were observed in a hypophysectomized patient, indicating that this effect of GIF was independent of suppression of growth hormone secretion. Cyclic and linear GIF, when administered in normal subjects during an infusion of synthetic human gastrin I, almost totally suppressed gastric secretion. The results indicate that GIF is a potent inhibitor of gastric secretion and gastrin release.

Gastric Juice↗