Acute or chronic zinc administration may cause hyperglycemia in experimental animals. These findings are attributed to permissive actions of glucocorticoids and glucagon upon hepatic gluconeogenesis and glycogenolysis. The effect of Zn(+)+ on plasma glucose, C-peptide, glucagon, and cortisol was investigated in healthy and insulin-dependent diabetes mellitus (IDDM) patients. Ten normal ...

The present investigation was undertaken to characterize the direct inhibitory action of the peroxyvanadium compounds oxodiperoxo(1, 10-phenanthroline) vanadate(V) (bpV(phen)) and oxodiperoxo(pyridine-2-carboxylate) vanadate(V) (bpV(pic)) on pig microsomal glucose-6-phosphatase (G-6-Pase) activity and on glucagon stimulated hyperglycemia in vivo. Both bpV(phen) and bpV(pic) were found to be potent competitive inhibitors of G-6-Pase with ...

The concentration of glucose is tightly regulated in the blood by a complicated set of physiological variables. To provide students with a means to more readily understand these complex mechanisms, the control of the water level in a beaver pond is presented as an analogy. A beaver must maintain a ...

The effects of glucagon infusions on expression of mRNA for enzymes that regulate gluconeogenesis were studied in lactating cows. Normal cows and cows with fatty liver that were susceptible to ketosis were assigned to either glucagon-treated or control groups. Glucagon at 0 or 10 mg/d was infused for 14 d ...

Intracellular mechanisms through which insulin inhibits glucagon secretion remain to be elucidated in glucagon secreting cells. In this study, we confirmed that, in In-R1-G9 cells, a pancreatic alpha cell line, insulin stimulated phosphorylation of insulin receptor substrate-1 (IRS-1) and activated phosphatidylinositol 3-kinase (PI3-kinase). We further studied, using wortmannin, an inhibitor ...

Insulin counterregulatory hormones play a major role in the maintenance of glucose homeostasis. To evaluate the hypothesis that the reported imprecise control of glucose production by insulin is mirrored by a corresponding lack of response to the various insulin counterregulatory hormones, 30 spontaneously delivered mixed-breed term lambs weighing 4.9 +/- ...

Endogenous glucose production has been shown to increase during administration of glucagon + fructose, but not during administration of fructose alone. To determine the mechanisms by which glucagon exerts this action, endogenous glucose production (EGP) and gluconeogenesis from fructose (GNF) were measured in eight healthy subjects infused 1) with graded ...

The effects of alpha- and beta-2-deoxy-D-glucose tetraacetate (1.7 and 8.5 mM) on insulin, somatostatin, and glucagon secretion from isolated rat pancreases perfused in the presence of 8.3 mM D-glucose were compared with those of unesterified 2-deoxy-D-glucose tested at the same two concentrations. The unesterified glucose analog caused, in a concentration-related ...

Insulin resistance syndrome has recently been described as a unifying hypothesis to explain the relationship between the many risk factors of coronary heart disease. Carbohydrate that is malabsorbed and fermented in the colon has been demonstrated to decrease insulin response to a glucose load and improve other risk factors associated ...

This experiment was designed to compare the effects of high ambient temperature and of feed restriction on plasma hormones and metabolites in primiparous lactating sows. Females were exposed to a constant thermoneutral (20 degrees C) or hot environment (30 degrees C) during lactation. Sows housed at 30 degrees C were ...

1. Mice were subjected to gastrectomy (GX) or food deprivation (24 h). The release of insulin and glucagon in response to different secretagogues was monitored in vivo and in isolated islets 3-4 weeks after surgery. 2. GX animals responded to glucose with an impaired glucose tolerance and a poor increase ...

OBJECTIVES: The distribution of serotonin (5-HT) and its effect on insulin and glucagon secretion were investigated to examine whether there are changes in the pattern of distribution and effect of 5-HT after the onset of experimental diabetes. METHODS: The pattern of 5-HT and its effect of insulin and glucagon secretion ...

Glucagon-like peptide-1 is the main hormonal mediator of the enteroinsular axis. Recently, it has additionally received considerable attention as a possible new treatment for Type II (non-insulin-dependent) diabetes mellitus. Its major disadvantage is that its duration of action is too short to achieve good 24-h metabolic control. Exendin-4, which is ...

The aim of this study was to determine differences in levels of the major hormones responsible for glucose homeostasis (insulin and glucagon) in babies with acute neonatal encephalopathy secondary to perinatal asphyxia and to correlate these with outcome. In a prospective observational study, plasma insulin, C-peptide, glucagon and serum glucose ...

Islet amyloid polypeptide (IAPP, or amylin) is produced in pancreatic beta-cells. The intraislet significance of IAPP is still uncertain. In the present study, paracrine effects of endogenous IAPP and somatostatin were investigated in isolated rat pancreatic islets. The intraislet IAPP activity was inhibited with an IAPP antiserum or a specific ...

The in vivo effects of three new analogs of somatostatin (ASS-51, ASS-52 and ASS-53 analogs) on GH, insulin and glucagon were studied in WKY rats. The solid phase method was used for the synthesis of ASS. Octreotide and ASS were given iv. in a dose of 0.05 &mgr;g/kg per animal ...

(1) Human biogenetic glucagon has replaced traditional glucagon of animal origin. It is the same substance but is obtained through a different manufacturing process. (2) The file on the efficacy and safety of biogenetic glucagon is limited. It suggests nevertheless that the hyperglycaemic effect of biogenetic glucagon is equivalent to ...

This study examined the selected hormonal responses to, and hormone-mediated glucose metabolism during minimally invasive surgery in, patients undergoing laparoscopic cholecystectomy for symptomatic gallstone disease. Thirty-two patients with symptomatic gallstone disease were included in this study and scheduled for open or laparoscopic procedure in a randomized trial. Results are expressed ...

BACKGROUND & AIMS: Glucose and galactose are absorbed by the small intestine via the sodium-dependent glucose transporter 1 (SGLT1) and fructose via the facilitated glucose transporter 5. A stimulatory effect of enteric glucagon 37 and pancreatic glucagon 29 on intestinal carbohydrate absorption has been shown. However, only glucagon 37 is ...

The aim of this work was to determine whether Psammomys obesus living in its natural habitat displays variation in the function of the endocrine pancreas. Live animals were collected regularly through the year by strip sampling. Plasma glucose varied during the year. Glucose levels were higher in periods I and ...

The catabolic state of poorly controlled type 1 diabetes has largely been attributed to insulin deficiency. However, the role of hyperglucagonemia, which occurs concomitantly with insulin deficiency, has not been fully investigated. We studied the effects of hyperglucagonemia during insulin deprivation on energy expenditure (using indirect calorimetry) and protein metabolism ...

The factors that regulate glucagon biosynthesis and proglucagon gene expression are poorly defined. We previously reported that insulin inhibits proglucagon gene expression in vitro. In vivo, however, the effects of insulin on the regulation of the proglucagon gene have been controversial. Furthermore, whether glucose plays any role alone or in ...

Glutamine is an important gluconeogenic amino acid in postabsorptive humans. To assess the effect of glucagon on renal and hepatic glutamine gluconeogenesis, we infused six normal healthy postabsorptive subjects with glucagon at a rate chosen to produce circulating glucagon concentrations found during hypoglycemia and, using a combination of isotopic and ...

OBJECTIVE: People with type 1 diabetes frequently develop a blunted counterregulatory hormone response to hypoglycemia coupled with a decreased hepatic response to glucagon, and consequently, they have an increased risk of severe hypoglycemia. We have evaluated the effect of insulin lispro (Humalog) versus regular human insulin (Humulin R) on the ...

We propose that blood glucose is regulated by a principle which we call integral rein control, in which under most conditions both glucagon and insulin are produced and control is achieved by altering the balance between the two. Like other integral control systems, the mechanism achieves zero steady-state error, which ...

BACKGROUND: The aim of this study was to determine whether therapeutically used branched-chain amino acids (BCAAs) solution influences glucose metabolism in liver cirrhosis (LC). METHODS: BCAAs solution (200 ml) was infused in LC patients at different stages, and plasma concentrations of glucose and pancreatic hormones were determined. RESULTS: In patients ...

Insulin and four peptides derived from the posttranslational processing of proglucagon have been isolated in pure form from the pancreas of the cane toad, Bufo marinus. Although Bufo insulin contains 9 amino acid substitutions, compared with human insulin, all those residues that are considered to be involved in receptor-binding and ...

To utilize hepatocytes for insulin-producing surrogate cells, we devised a regulatory secretion system by placing proinsulin DNA under the regulatable promoter for phosphoenolpyruvate carboxykinase (PEPCK). The expression of PEPCK is down-regulated by insulin, and up-regulated by cAMP and glucagon. To express insulin in hepatocytes, we constructed an adenoviral insulin expression ...

Quantitative determination of insulin secretion is of importance both clinically and in research. The optimal method has not been established, although several different methods have been used. We determined the reproducibility of islet function parameters obtained by the glucose-dependent arginine stimulation test, and also studied the priming effect of arginine ...

In isolated perfused pancreas from normal rats, a rise in d-glucose concentration from 3.3 to 8.3 mM provoked a rapid phasic stimulation of both insulin and somatostatin secretion and rapid fall in glucagon output, these changes being reversed when the concentration of the hexose was brought back to its initial ...

We have recently cloned the murine glucagon receptor (GR) gene and shown that it is expressed mainly in liver. In this organ, the glucagon-GR system is involved in the control of glucose metabolism as it initiates a cascade of events leading to release of glucose into the blood stream, which ...

To determine the metabolic responses to surgical trauma, we assessed the rates of whole body (WB) proteolysis and glucose turnover using established isotopic techniques in combination with interorgan amino acid and substrate balances (using arteriovenous differences times flow) after laparotomy. Circulating levels of hormones and mediators known to affect these ...

After pancreas-kidney transplantation, it is difficult to obtain an accurate estimate of the insulin secretion of the pancreas graft, since several pitfalls are involved using peripheral C-peptide and/or insulin measurements in this determination. In this study, the individual kinetic parameters of C-peptide and then the rates of insulin secretion were ...

The ontogenesis, postnatal development and ageing of the endocrine pancreas in mammals have not been extensively studied. In order to improve understanding of this organ, we studied the buffalo pancreas during fetal and postnatal development. Glucagon, insulin and somatostatin immunoreactive cells (i.c.) were first seen in 2-mo-old embryos. Pancreatic polypeptide ...

By introducing an intensified insulin treatment regime to patients with insulin-dependent diabetes mellitus (IDDM), the frequency of long-term complications that the patient will experience has been shown to decrease. The price is an increase in the frequency of severe and mild hypoglycaemic events. Therefore, constant monitoring of these patients is ...

Male toads, weighing 70-123 g, were divided into 13 groups with 8 toad in each group. Animals in each group were fasted overnight before the experiments. Toads in groups 1 to 4 were infused for 30 minutes with adrenaline, 5 ugkg-1 min-1, glucose, 5.5 mg kg-1 min-1; glucagon 2 ugkg-1 ...

BACKGROUND/AIMS: The aim of this study was to investigate glucagon and insulin metabolism in order to clarify the mechanisms that lead to hyperglucagonemia and hyperinsulinemia in cirrhosis. METHODOLOGY: Splanchnic output and metabolic clearance rates were studied in 16 cirrhotic patients and 5 non-cirrhotic controls. Splanchnic glucagon and insulin output into ...

OBJECTIVE: To evaluate the inhibitory effects of octreotide and diazoxide on insulin secretion in patients with type 1 diabetes and measurable levels of circulating C-peptide. RESEARCH DESIGN AND METHODS: Diazoxide was given to six patients during a 7-day period (100 mg three times daily), followed by a 3-week washout. Subsequently, ...

The aim of this study was to investigate the possible role of porcine calcitonin gene-related peptide (CGRP) in the regulation of the endocrine porcine pancreas. Initially, we isolated and purified CGRP from extracts of porcine adrenal glands and pancreases. A single molecular form of the peptide was found in the ...

To determine the time course of glucagon activation and deactivation of hepatic glucose production (HGP), studies were conducted in 18-hour fasted, conscious dogs. Somatostatin was infused with insulin replaced intraportally at 1.8 pmol x kg(-1) x min(-1) and glucagon replaced peripherally at 1.0 ng x kg(-1) x min(-1). After a ...

BACKGROUND/AIMS: Insulin secretion is increased in cirrhotic patients without diabetes but decreased in cirrhotic patients with diabetes. Increased glucagon secretion is found in both groups. Our aim was to determine: 1) whether alterations in insulin secretion are due to changes in maximal secretory capacity or altered islet B-cell sensitivity to ...

The pancreatic islets are innervated by nerves emanating from intra- and extrapancreatic ganglia. However, the effects of ganglionic activation on insulin and glucagon release in vivo have not been established. We therefore investigated the effects of pharmacological ganglionic activation by the nicotinic agonists DMPP (1,1-dimethyl-4-phenylpiperazinium iodide) and nicotine on insulin ...

The influence of distal pancreatectomy on portal and peripheral blood immunoreactive insulin (IRI) and immunoreactive glucagon (IRG) concentrations was evaluated in patients undergoing total gastrectomy. There were 22 patients studied, 12 of whom did not undergo distal pancreatectomy (group 1), and 10 who did (group 2). In group 2, the ...

We present an infant with severe familial hyperinsulinism in whom glucose production rate, lipolysis, and gluconeogenesis from glycerol were measured by use of glucose and glycerol labelled with stable isotopes. Administration of a single dose of glucagon (0.1 mg/kg) caused an increase in glucose production rate by near 140% from ...

The present experiments sought to determine whether glucagon concentrations mimicking those observed in people with diabetes mellitus alter postprandial carbohydrate metabolism in nondiabetic humans. We measured the gastric emptying of solids and liquids, the systemic rate of appearance of ingested glucose, and endogenous glucose production either when postprandial suppression of ...

This study was designed to characterize the impact of endurance training on the hepatic response to glucagon. We measured the effect of glucagon on hepatic glucose production (HGP) in resting trained (n = 8) and untrained (n = 8) healthy male subjects (maximal rate of O2 consumption: 65.9 +/- 1.6 ...

NIDDM is associated with excessive rates of endogenous glucose production in both the postabsorptive and postprandial states. To determine whether this is due to an intrinsic increase in hepatic sensitivity to glucagon, 9 NIDDM and 10 nondiabetic subjects were studied on three occasions. On each occasion, glycogen was labeled the ...

Since the effects of ketamine sedation seem to differ between subspecies of baboons, we assessed the endocrine response to an intravenous glucose tolerance test (IVGTT) in 12 hamadryas baboons. The first phase insulin secretion, basal insulin, and glucose levels, as well as the glucose clearance, were significantly lower in sedated ...

Seventeen diabetic patients (5 males and 12 females) treated with long-term metformin therapy received their morning dose after an overnight fast or after one of four types of breakfast: low protein, low fat, low carbohydrate or standard. Mean (+/- SD) and median areas under the serum concentration curves (AUC), maximum ...

We have shown that the glucagon irresponsiveness to hypoglycemia in diabetic rats is markedly improved by correction of hyperglycemia independent of insulin. In contrast, normalization of glycemia by insulin did not improve this response. To find out whether these glucagon responses reflect changes in islet glucagon, we directly quantified glucagon ...