Glucagon response to arginine after treatment of diabetes mellitus.

To investigate the aminogenic glucagon response in diabetes mellitus, arginine infusion tests were carried out on twenty-four diabetic patients before and after treatment. Eleven healthy men served as a control group. Plasma glucagon was measured by radioimmunoassay using an antiserum, G21, specific for pancreatic glucagon. Out of twenty-four patients, five were treated with diet alone, eight with sulfonylurea, and eleven with insulin. In all these diabetic groups, the glucose tolerance improved after treatment for diabetes mellitus, while the insulin response to the glucose did not show any remarkable change. The fasting levels of the plasma glucagon did not differ from that of the normal subjects both before and after treatment. Hyperresponsiveness of the plasma glucagon to arginine infusion was observed in all diabetic groups, in comparison with that of the normal controls. The exaggerated response of the plasma glucagon to arginine was lowered following appropriate treatment in each diabetic group. However, as far as the changes in glucagon area during the arginine test are concerned, the aminogenic hyperresponsiveness of the plasma glucagon was reduced prominently in the diabetic group treated with sulfonylurea. The relationship between the response of glucose and plasma insulin and between glucose and glucagon to arginine was investigated, and the importance of the changes in the insulin:glucagon ratio was emphasized. Moreover, the possibility that long-term administration of a sulfonylurea may reduce an exaggerated glucagon response to arginine was discussed.     

C-peptide response to glucagon. A test for the residual beta-cell function in diabetes mellitus.

Pancreatic beta-cell secretory activity was measured in 17 patients with insulin-dependent diabetes mellitus of less than 19 months' duration and in 10 nondiabetic subjects by means of the peripheral plasma C-peptide response to 1 mg. of glucagon I.V. The C-peptide response to a meal was also measured in the diabetic patients. Residual beta-cell function was present in all the diabetic patients as indicated by significant amounts of C-peptide in plasma. Significant increases in C-peptide were observed in 16 after glucagon stimulation and in 15 after the meal. Both absolute and relative increase in C-peptide were reduced in the diabetic patients. The increase in C-peptide was correlated to the fasting C-peptide concentration both after glucagon (r=0.86, p less than 0.001) and after the meal (r=0.66, p less than 0.01). The responses to the meal and to glucagon were correlated (r=0.77, p less than 0.005), indicating a high predictive value of the glucagon test as to how the beta-cells will respond during normal daily life.     

Plasma glucagon and the insulin:glucagon ratio in gestational diabetes.

The influence of pregnancy on serum glucose, serum insulin, and plasma glucagon concentrations was studied in eight normal women and 14 nonobese gestational diabetics. Each normal individual was subjected to an oral glucose tolerance test in midpregnancy, and all subjects were investigated late in pregnancy and again four to six weeks postpartum. As compared with the postpartum values, fasting glucose concentration decreased during gestation in the normals and increased in the gestational diabetics, but the changes were small and insignificant. In contrast, fasting insulin concentration increased equally and significantly in pregnancy in both groups. Likewise, the glucagon concentration was enhanced in the fasting state in both groups in pregnancy. However, the molar insulin-to-glucagon ratio was significantly elevated in both normals and gestational diabetics. In late pregnancy the magnitude of the insulin response to oral glucose (i.e., the incremental insulin area above fasting baseline) was equally and significantly enhanced in the normals and the gestational diabetics. However, when the insulin response during the first 60 minutes of the OGTT was expressed per unit of glucose stimulus (i.e., the delta insulin/delta glucose ratio) a significantly higher mean response was found in the normal pregnants than in the gestational diabetics. In pregnancy and postpartum, plasma glucagon always decreased to levels significantly below fasting levels after glucose ingestion. In normal midpregnancy the degree of suppression of glucagon was close to that of postpartum, whereas an exaggerated and prolonged suppression was found in late pregnancy in the normals as well as the gestational diabetics. These findings indicate that plasma glucagon and serum insulin concentrations are profoundly influenced by pregnancy. As the changes, however, lead to an increased insulin-to-glucagon ratio, the diabetogenicity of pregnancy is not explained by this relationship.     

糖尿病人胰岛素分泌功能差异对骨代谢的影响

为了解糖尿病人胰岛素水平的高低对骨代谢影响和程度,检测其馒头餐前后胰岛素和血糖水平,用跟骨超声波传导速度（ＳＯＳ）、振幅衰减（ＢＵＡ）和骨硬度指数（ＳＴＩ）。结果显示糖尿病各组ＳＯＳ、ＢＵＡ及ＳＴＩ均低于对照组,其中以胰岛素分泌低下组最明显,分泌延迟组和分泌过高组比较无显差异。组间比较,胰岛素分泌低下组胰岛素水平最低,而相应时限血糖值最高。胰岛分泌过高组胰岛素水平最高,但相应血糖值高于对照组,并     

Hypoxemic stimulation of heart glycogen synthase and synthesis. Effects of insulin and diabetes mellitus

With radiotracer and 13C nuclear magnetic resonance (13C-NMR) methods, we studied the time course of glycogen resynthesis after three 90-s episodes of hypoxemia in both control and diabetic rats in vivo. Glycogen synthesis was measured in the presence and absence of infused insulin and compared with the changes in glycogen synthase (GS) and phosphorylase activities. We observed in 13C-NMR spectra the expected mobilization of glycogen during hypoxia in vivo. In control rats with or without exogenous insulin, this was followed by a rapid resynthesis of glycogen during a 40-min recovery period. A marked activation of GS was observed by 10 min (glucose-6-phosphate-independent form of GS [GSl] = 0.65 mumol.min-1.g-1 or 92% of total GS), and activation persisted up to 40 min in both groups. Glycogen synthesis during the recovery period averaged 0.51 and 0.45 mumol.min-1.g-1 in the saline- and insulin-treated rats, respectively. In the diabetic rats by 10 min after hypoxemia, GSl increased only modestly in both saline-treated (0.16 mumol.min-1.g-1) and insulin-treated (0.21 mumol.min-1.g-1) rats, and activation persisted up to 40 min only with insulin treatment. Glycogen synthesis was slower in the diabetic rats given insulin (0.28 mumol.min-1.g-1) and essentially absent in the saline-treated rats (0.03 mumol.min-1.g-1) compared with controls. We conclude that recovery from hypoxemia is accompanied by a marked activation of GSl and rapid rates of glycogen synthesis in nondiabetic rats, and diabetes markedly blunts this response. Acute insulin infusion only partially overcomes this block.(ABSTRACT TRUNCATED AT 250 WORDS)     

Response of insulin, glucagon and growth hormone to arginine infusion in patients with chronic renal failure.

To determine whether glucose intolerance in patients with chronic renal failure could improve by hemodialysis, the effects of arginine infusion on the concentration of blood sugar, insulin, glucagon, growth hormone were examined in healthy volunteers, undialyzed and dialyzed patients with chronic renal failure. Plasma concentrations of sugar and hormones in undialyzed and dialyzed patients responded similarly to arginine infusion. While blood samples were collected at 30, 45, 60, 90, 120 and 180 min after beginning infusion of arginine, the concentrations of sugar and hormones in both patients had no statistically significant differences. However, plasma concentrations of growth hormone in both patients 180 min after beginning of arginine infusion gave statistically significant differences. In the present study, the results suggest that hemodialysis might not improve the glucose tolerance in the patients with chronic renal failure.     

Plasma C-peptide and insulin responses to intravenous glucagon stimulation in idiopathic haemochromatosis

Beta-cell reserve was investigated in 15 patients with proven idiopathic haemochromatosis (IHC) (7 normoglycaemic haemochromatotic patients, 4 non-insulin-requiring diabetics and 4 insulin-requiring diabetics) by measuring the response of plasma C-peptide, insulin and glucose to a 2 mg intravenous bolus of glucagon, and compared with that in 5 lean normal subjects. The corresponding C-peptide/insulin molar ratios were also calculated. Despite the significant fasting hyperglycaemia in the insulin-requiring haemochromatotic diabetics, mean fasting C-peptide concentrations were similar in all four groups. However, after glucagon stimulation the C-peptide response was significantly reduced in the insulin-requiring group over the whole period of observation. A trend in insulin response to glucagon was noted, with the highest values in the non-diabetic haemochromatotic patients, followed by the controls and then by the non-insulin-requiring diabetics, although there were no significant differences. In contrast, C-peptide/insulin molar ratios after glucagon were significantly reduced in the normoglycaemic IHC group. These results suggest the presence of at least two abnormalities of insulin metabolism in IHC--a progressive reduction in beta-cell function and a diminished rate of removal of insulin by the liver.     

Biliary response to glucagon and insulin following hepatic transplantation in humans

Glucagon and insulin are postulated to be physiologic regulators of hepatic biliary secretion. Effects of these hormones were studied following orthotopic transplantation. Five adult hepatic graft recipients had triple lumen t-tubes placed at the time of surgery and were studied 3 months after surgery. Experiments were performed after cholangiographic confirmation of t-tube placement and function. After overnight fast, t-tubes were inflated and bile was collected. A small quantity was saved for analysis and the remainder was reinfused to maintain enterohepatic circulation. After 1 hr of observation, the patients received a 2-hr infusion of insulin (0.125 U kg-1 hr-1), glucagon (2 micrograms kg-1 hr-1), or 0.9% saline. During saline infusions, all parameters remained stable. As has been previously demonstrated in the canine model and intact patients, bile salt outputs were constant under all experimental conditions. Glucagon stimulated bile secretion by 30% (6.7 +/- 1.5 to 8.7 +/- 1.2 ml/15 min) and inhibited biliary cholesterol output by 47% (16.4 +/- 3.2 to 8.7 +/- 1.5 mg/15 min). Bile flow and lipid secretion were not affected by insulin. Glucagon had profound effects on bile flow and lipid secretion, suggesting effects independent of innervation, while insulin at this dose had no statistically significant effects.     

Loss of the decrement in intraislet insulin plausibly explains loss of the glucagon response to hypoglycemia in insulin-deficient diabetes: documentation of the intraislet insulin hypothesis in humans

The intraislet insulin hypothesis for the signaling of the glucagon secretory response to hypoglycemia states that a decrease in arterial glucose --> a decrease in beta-cell insulin secretion --> a decrease in tonic alpha-cell inhibition by insulin --> an increase in alpha-cell glucagon secretion. To test this hypothesis in humans, a hyperinsulinemic- euglycemic ( approximately 5.0 mmol/l [90 mg/dl] x 2 h) and then a hypoglycemic ( approximately 3.0 mmol/l [55 mg/dl] x 2 h) clamp was performed in 14 healthy young adults on two occasions, once with oral administration of the ATP-sensitive potassium channel agonist diazoxide to selectively suppress baseline insulin secretion and once with the administration of a placebo. The decrement in plasma C-peptide during the induction of hypoglycemia was reduced by approximately 50% in the diazoxide clamps (from 0.3 +/- 0.0 to 0.1 +/- 0.0 nmol/l [0.8 +/- 0.1 to 0.4 +/- 0.1 ng/ml]) compared with the placebo clamps (from 0.4 +/- 0.0 to 0.1 +/- 0.0 nmol/l [1.2 +/- 0.1 to 0.4 +/- 0.1 ng/ml]) (P = 0.0015). This reduction of the decrement in intraislet insulin during induction of hypoglycemia caused an approximately 50% reduction (P = 0.0010) of the increase in plasma glucagon in the diazoxide clamps (from 29 +/- 3 to 35 +/- 2 pmol/l [102 +/- 9 to 123 +/- 8 pg/ml]) compared with the placebo clamps (from 28 +/- 2 to 43 +/- 5 pmol/l [98 +/- 7 to 151 +/- 16 pg/ml]). Baseline glucagon levels, the glucagon response to intravenous arginine, and the autonomic (adrenomedullary, sympathetic neural, and parasympathetic neural) responses to hypoglycemia were not altered by diazoxide. These data indicate that a decrease in intraislet insulin is a signal for the glucagon secretory response to hypoglycemia in healthy humans. The absence of that signal plausibly explains the loss of the glucagon response to falling plasma glucose concentrations, a key feature of the pathogenesis of iatrogenic hypoglycemia, in insulin-deficient (type 1 and advanced type 2) diabetes.     

Effect of insulin therapy on renal hemodynamic response to amino acids and renal hypertrophy in non-insulin-dependent diabetes.

Since renal hemodynamic disturbances are important in renal injury and are exacerbated by elevated plasma amino acid concentrations in insulin-dependent diabetes, we measured glomerular filtration rate (GFR) and renal plasma flow (RPF) after an overnight fast and during amino acid infusion in 12 patients with NIDDM and nine normal subjects. In the diabetic patients (plasma glucose 12.4 +/- 0.6 mmol/liter), the fasting GFR (113 +/- 6 vs. 98 +/- 7 ml/min.1.73 m2 in normal subjects, P = 0.056) and RPF (635 +/- 37 vs. 540 +/- 20 ml/min.1.73 m2 in normal subjects, P less than 0.05) were increased. After amino acid infusion, the increase in GFR (159 +/- 7 vs. 121 +/- 6 ml/min.1.73 m2 in normal subjects, P less than 0.05) and RPF (970 +/- 51 vs. 700 +/- 18 ml/min.1.73 m2 in normal subjects, P less than 0.05) were augmented. Insulin infusion for 36 hours did not change these responses. After three weeks of insulin therapy (plasma glucose 5.9 +/- 0.2 mmol/liter), the amino acid-stimulated GFR (143 +/- 5 ml/min.1.73 m2) and RPF (836 +/- 30 ml/min.1.73 m2) declined (P less than 0.05), while the fasting values remained unchanged. The right kidney volume was measured by ultrasonography and found to decrease after three weeks of insulin therapy from 188 +/- 12 to 165 +/- 9 ml/1.73 m2 (P less than 0.05). However, both values were greater than that in the normal subjects, 124 +/- 13 ml/1.73 m2 (P less than 0.01). Glomerular hyperfiltration and hyperperfusion became augmented during hyperaminoacidemia in our NIDDM patients.(ABSTRACT TRUNCATED AT 250 WORDS)     

Biliary response to glucagon in humans.

Glucagon has been demonstrated to have profound effect on biliary secretion in several species. Glucagon's biliary effects were studied in humans following biliary tract surgery. Nine patients underwent common bile duct exploration and insertion of a balloon-occludable t tube. An aliquot of the collected sample was kept and the enterohepatic circulation was maintained by reinfusion of the collected bile via the distal t-tube port. Glucagon increased bile flow and decreased cholesterol and phospholipid output during stable bile acid output. Furthermore high-performance liquid chromatographic analysis of bile acid profiles revealed no significant changes in bile salt species or conjugation after glucagon infusion. Glucagon is probably important in the physiologic regulation of biliary secretion in humans.     

Hypoglycemia with insulin in post-transplant diabetes mellitus

IntroductionTo prevent hypoglycemic episodes, the management of insulin therapy against post-transplant diabetes mellitus (PTDM) is important. We compared glargine (long-acting insulin) versus NPH isophane (intermediate-acting insulin) as an armamentarium against PTDM. Indeed, the study evaluated PTDM patients with hypoglycemic episodes treated with isophane or glargine.Material and methodsWe evaluated a total number of 231 living-donor renal transplant recipients with PTDM of age ≥ 18 years admitted to the hospital between January 2017 and September 2021. However, patients taking hypoglycemic agents before transplantation were excluded from this study. Out of 231 patients, 52 (22.15%) suffered from PTDM out of whom 26 were treated with glargine or isophane.ResultsAfter applying exclusion criteria, out of 52 PTDM patients 23 were included in the study: 13 PTDM patients were treated with glargine, whereas 10 PTDM patients with isophane. Our analysis revealed 12 episodes of hypoglycemia in glargine-treated PTDM patients compared to 3 in isophane-treated PTDM patients (p = 0.056). Clinically, 9 out of 15 hypoglycemic episodes were nocturnal (60%). Furthermore, no other risk factors were observed in our study population. Detailed analysis showed that both groups had equivalent doses of immunosuppressants and oral hypoglycemic agents. The odds ratio for hypoglycemia in the group treated with isophane compared to that treated with glargine was 0.224 (95% CI, 0.032–1.559). Glargine users recorded significantly lower blood sugar levels before lunch, dinner and at bedtime with p-values of 0.001, 0.009 and 0.001 respectively. A better hemoglobin A1c (HbA1c) level was seen in the glargine vs. isophane group (6.98 ± 0.52 vs. 7.45 ± 0.49, p-value 0.03).ConclusionThe study shows better blood sugar control with long-acting insulin analog, glargine, than with intermediate-actin analog, isophane. Overall, a higher number of hypoglycemic episodes was nocturnal. Long term safety of long-acting insulin analogs needs to be further studied.