Glucose, FFA, IRI and GH Response to I.V. Glibenclamide

Abstract

303An attempt has been made to understand the possible reasons of failure to oral sulphonylurea therapy in maturity onset diabeties by studying acute changes in blood glucose, plasma FFA, IRI and GH following intravenous (IV) glibenclamide. Material and MethodsAge and sex matched maturity onset diabetics under g1ibenclamide trial were studied in two groups. (I) Controlled: n = 16, diabetics successfully treated with 2.5-20 mg/day of glibenclamide orally. (2) Failure: n"16, those who on uninterrupted therapy for three months with 20 mg glibenclamide daily continued to have hyperglycemia (F & 2 hr pp blood sugar 180 mg/IOO ml).lV g1ibenclamide test was performed after overnight fast and 48 hours after withdrawal of oral drug. A fasting venous blood sam pie was collected, 1 mg glibenclamide was injected IV and subsequently blood was collected after 5, 15, 30,60 and 90 minutes. Blood glucose (Nelson 1944), FFA (Novak 1965), IRI (Welborn and Fraser 1965) and GH (Hartog, Gaafar, Meisser and Fraser 1964) were estimated in each sampie. , LangTimd Vortel (1969), and more recently Greider and McGuigan (1971) demonstrated the presence of gastrin in normal pancreatic islets by mcans of immunofluorescenee. In the same paper, Greider and McGuigan confirmed its presence by radioimmunoassay hut in far smaller levels than in antral gastric mucosa. Applying a biochemical method based on ammonium sulfate precipitation and column chromatographies, we have extracted from hog pancreas a fraction which stimulates gastric acid sccrction in thc rat Although this fraction reacts with porcine gastrin antibodies (Accary. Pointner. Dubrasquet and Bonfi/s 1972) in a radioimmunoassay system, its chromatographie behaviour differs from that of antral gastrin in various systems.. As an explanation of this discrepancy the following hypothesis can be formulated: 1) at least two substances are prcsent, one of them being gastrin; 2) there is only onc sccretagogue substance; in this case immunoreactivity is duc to cross reaction of the fraction with porcinc gastrin antibodics. LomskyDownloaded by: East Carolina University. Copyrighted material.