The present study was designed to determine the effect of naloxone, a specific opiate receptor antagonist, on postprandial levels of insulin, glucagon, pancreatic polypeptide (PP), somatostatin-like immunoreactivity (SLI) and gastrin in response to carbohydrate and fat-rich test meals in a group of 6 healthy volunteers. The addition of naloxone to a meal consisting of 50 g sucrose dissolved in 200 ml water augmented the rise of plasma insulin levels significantly during the first 30 min after its ingestion and reduced the rise in plasma insulin and pancreatic polypeptide and elevated glucagon levels during the last 30 min of the experimental period. When sucrose was dissolved in 200 ml cream the addition of naloxone augmented the postprandial rise of insulin levels between 15 and 60 min after ingestion of the meal and elicited an increase of plasma SLI and PP levels throughout the entire experimental period which indicates that post-prandial levels of insulin, glucagon, PP and SLI are modulated via endogenous opiate receptors during the ingestion of carbohydrate and fat test meals and that this effect depends on the composition of the ingested nutrients. These data raise the possibility that endogenous opiates participate in the regulation of postprandial insulin, glucagon, somatostatin and pancreatic polypeptide release not only in certain disease states as demonstrated recently for insulin secretion in type II diabetes mellitus but endogenous opiates may also be of importance under physiological conditions.

Adult↗

PubMedDate not supplied

Immunologic properties of biosynthetic human insulin in vitro.

Some immunologic properties of biosynthetic human insulin (BHI) were examined in vitro. An identical behavior was found for BHI and pancreatic human insulin as standard preparation and for A14-mono-labeled BHI and pork insulin as tracer in the insulin radioimmunoassay. BHI proved to be free of human proinsulin and C-peptide. Insulin antibodies in serum of two diabetic patients showed a preferential binding of 125I-bovine insulin. However, the antibody titers were almost identical for A14-mono-labeled BHI and pork insulin. These studies did not reveal any characteristic immunologic properties of BHI compared with highly purified pancreatic human and pork insulin.

Animals↗

PubMedDate not supplied

Glucagon as a non species-specific regulator of the glycaemia in honeybee (Apis mellifica).

It is known that hormones which exist in vertebrates are very old in respect to evolution. The presence of insulin and glucagon in insects had already been suggested in the early sixties. In this study honeybees are living in an "artificial hive" in the German laboratory under exactly standardized conditions. In the French laboratory standardized conditions yielded because only emerging worker bees were used i.e. those which were just slipping from the honeycomb alveoli. It seemed of interest to introduce an in vivo model in which one animal is punctured at tergum III in order to gain 1 microliter hemolymph using a glass capillary tube . *For the first time it is possible to puncture one animal three times. The main sugars in the hemolymph were silylated* and determined by gas chromatography in the German resp. by nano thin layer chromatography in the French laboratory. 0-500 ng porcine glucagon resp. the same amount of purified bee glucagon were injected to the animals and the action on carbohydrates observed during 2 hours. Similar to the action of glucagon in vertebrates, carbohydrate metabolism although completely different, appears to be regulated in part in this invertebrate stem. It is concluded that glucagon may represent a key hormone for degradation of the glycogen stores.

Acclimatization↗