Positive alliesthesia after insulin

Summary Volunteers experienced sucrose solution as more pleasant 36–48 min after insulin, than after saline control. These changes in affective estimates correlate negatively with blood sugar at 30 min and positively at 50 min after the insulin injection.     

Effect of vagal denervation on insulin release after oral and intravenous glucose

Zusammenfassung Perorale Glykosebelastung ergab bei vagotomierten Ratten Erhöhung des Blutglykosespiegels. Nach intravenöser Glykosezufuhr wurden niedrigere Werte von immunoreaktivem Insulin im Serum gefunden. Ebenso war der insulinogene Index bedeutend niedriger sowohl nach peroraler als auch nach intravenöser Glykosezufuhr. Vagotomie dürfte somit die glykosebedingte Insulinfreisetzung reduzieren.     

Effect of insulin on immunological phagocytosis by macrophages.

It was shown that, in physiological concentrations, insulin enhances, in vitro, the immunological phagocytosis of sensitized sheep erythrocytes by cultured mouse peritoneal macrophages. Insulin seems to stimulate macrophage phagocytosis as a cholinomimetic agonist by increasing the intracellular levels of cyclic GMP.     

Effect of insulin on the glucose uptake of protozoa.

Insulin stimulates the glucose uptake of Tetrahymena pyriformis. This shows the presence of insulin receptors in Tetrahymena, consequently receptors may be present in a level of phylogenesis, where the natural contact between the given hormone and the cell is unnecessary and impossible.     

Effect of dihydroergocristine infusion on tolbutamide-induced insulin secretion in man.

The insulinemic response to 1 g of tolbutamide i.v. is greatly enhanced (+ 145%) after a 60-min infusion of the alpha-lytic dihydrogenated ergot alkaloid, dihydroergocristine (83.3 micrograms/min, corresponding to a total dose of 5 mg) in 7 healthy subjects. No differences are observed in the glycemic responses.     

Positive and negative inotropic effects of carbachol on the embryonic chick atrium.

The effect of carbachol on twitch tension of atrial preparations from chick embryos of different incubation ages (3-14 days) was studied. At every age carbachol evoked negative (at low concentrations) and positive (at higher concentrations) inotropic responses. Maximal response values for both effects increased with age; in 3- and 5-day atria the positive inotropic response prevailed. The muscarinic antagonist pirenzepine inhibited the positive (on 5-day atria) and negative (on strips of 14-day atria) inotropic effects of carbachol with pA2 values of 6.8 and 8.0, respectively, suggesting that muscarinic receptors mediating these effects belong to different receptor subtypes.     

Effect of phosphate omission on glucose-induced insulin release in vitro.

In the isolated perfused rat pancreas, omission of extracellular phosphate (H2PO-4) significantly reduces the insulin secretion in response to 16.7 mM glucose.     

Insulin secretion and (pro)insulin biosynthesis of cultured mice islets after glibenclamide loading in vitro

Summary Isolated islets from C57B1/6J mice exposed to 10 mmoles/1 glucose supplemented with 5 g/ml glibenclamide for 48 h released significantly less insulin in the subsequent short-time incubation thanuntreated controls (without glibenclamide), whereas insulin biosynthesis was not suppressed by glibenclamide treatment.Investigations were carried out as a part of the ForschungsprojektDiabetes mellitus und Fettstoffwechselstörungen, supported by the Ministry of Health of the GDR.     

Insulin secretion and (pro)insulin biosynthesis of cultured mice islets after glibenclamide loading in vitro

Isolated islets from C57Bl/6J mice exposed to 10 mmoles/l glucose supplemented with 5 micrograms/ml glibenclamide for 48 h released significantly less insulin in the subsequent short-time incubation than untreated controls (without glibenclamide), whereas insulin biosynthesis was not suppressed by glibenclamide treatment.     

Proinsulin C-peptide elicits disaggregation of insulin resulting in enhanced physiological insulin effects

Using surface plasmon resonance (SPR) and electrospray mass spectrometry (ESI-MS), proinsulin C-peptide was found to influence insulin-insulin interactions. In SPR with chip-bound insulin, C-peptide mixed with analyte insulin increased the binding, while alone C-peptide did not. A control peptide with the same residues in random sequence had little effect. In ESI-MS, C-peptide lowered the presence of insulin hexamer. The data suggest that C-peptide promotes insulin disaggregation. Insulin/insulin oligomer μM dissociation constants were determined. Compatible with these findings, type 1 diabetic patients receiving insulin and C-peptide developed 66% more stimulation of glucose metabolism than when given insulin alone. A role of C-peptide in promoting insulin disaggregation may be important physiologically during exocytosis of pancreatic β-cell secretory granulae and pharmacologically at insulin injection sites. It is compatible with the normal co-release of C-peptide and insulin and may contribute to the beneficial effect of C-peptide and insulin replacement in type 1 diabetics. Received 3 May 2006; received after revision 9 June 2006; accepted 12 June 2006 Free Online Access     

Stimulation of glucagon and inhibition of insulin secretion evoked from carotid baroreceptors.

The influence from carotid baroreceptors on portal immuno-reactive glucagon and insulin levels and on arterial plasma glucose concentration was studied in vagotomized cats by sectioning of the sinus nerves. Such a complete elimination of the afferent baroreceptor discharge caused a prompt and pronounced increase in the glucose and glucagon levels, whereas the insulin concentration significantly decreased. The role of vascular barorecptors in the hyperglycemic response to hemorrhage is discussed.     

Rapid effects of insulin on cyclic GMP location in an intact protozoan.

We studied rapid changes in location of cyclic GMP in Tetrahymena pyriformis. Insulin caused cGMP localization in cilia and near the plasma membrane (0.5-1 min). Later (1-5 min) cGMP localization was diffuse in cytoplasm with perinuclear accentuation. Inactive insulin analogs did not elicit these changes.     

Effects of glucagon and insulin on the Paneth cells of the mouse duodenum.

The effect of glucagon and insulin on the paneth cells (PC) of the duodenum of the mouse was investigated using light microscopy. Both glucagon and insulin were able to increase significantly the number of the secretory granules of PC. This possibly means that these hormones are capable of inhibiting the secretion of PC.