Contribution of muscle and liver to glucose-fatty acid cycle in humans.

To examine the influence of elevated free fatty acid (FFA) levels on hepatic glucose production (HGP) and oxidative and nonoxidative pathways of glucose metabolism, 12 healthy subjects participated in two euglycemic insulin-clamp studies performed with and without infusion of Intralipid plus heparin. To elucidate the role of skeletal muscle in this putative interaction, we performed muscle biopsies for the measurement of activities of glycogen synthase (GS), pyruvate dehydrogenase (PDH), and carnitine palmitoyltransferase (CPT). Infusion of Intralipid plus heparin caused an increase in plasma FFA concentrations and rate of lipid oxidation (measured by indirect calorimetry) that was not inhibited by insulin.

Influence of portal delivery of insulin on intracellular glucose and lipid metabolism.

We have investigated whether portal delivery of insulin as a result of intrahepatic islet cell autografts would prevent the development of metabolic alterations. Seven pancreatectomized dogs received islet autografts transplanted into the liver through the portal vein (PD). One year after transplantation, their intravenous glucose tolerance and insulin responses were similar to age-matched control (C) dogs (n = 5).

Activity of enzymes of glucose and triglyceride metabolism in adipose and muscle tissue from normal pregnant women at term.

In order to further investigate insulin insensitivity in pregnancy, the activities of key enzymes in glycolysis and lipid metabolism were measured in adipose and muscle tissue biopsies from 20 normal pregnant women undergoing caesarean section at term, and 23 non-pregnant women of similar age and body weight undergoing gynaecological surgery. The activity of pyruvate kinase was decreased in pregnant women in both adipose tissue (0.015 (0.

Carbohydrate and lipid metabolism of skeletal muscle in type 2 diabetic patients.

Peripheral hyperinsulinaemia is the cause of metabolic changes that might contribute to the high incidence of macrovascular disease in patients with diabetes mellitus. In order to test this hypothesis muscle biopsies from 12 Type 2 diabetic patients and 14 age and sex matched non-diabetic patients, undergoing minor surgery, were obtained. The diabetic patients had significantly elevated fasting serum insulin (0.

Intracellular metabolism in biopsies from the aorta in patients undergoing coronary bypass surgery.

Abnormal glucose and lipid metabolism in striated muscles and arterial wall has been demonstrated in 3 species: the pig, the dog, and human Type 2 diabetic patients, sharing the common feature of peripheral hyperinsulinaemia. In this study eighteen consecutive patients undergoing coronary bypass surgery and eight control patients were examined. Prior to surgery an oral glucose tolerance test showed that eleven out of eighteen patients had impaired glucose tolerance and significantly elevated fasting immune reactive insulin (IRI) and C-peptide concentrations.

Evaluation of patients with local reactions to insulin with skin tests and in vitro techniques.

To better understand the part played by IgE and IgG antibody in the production of dermal reactions to insulin and the usefulness of skin tests in the evaluation of these reactions, we studied 21 diabetic patients referred for evaluation of large local insulin reactions, 46 diabetic patients without local insulin reactions, and 22 healthy nondiabetic controls. Study subjects were skin tested with 15 different insulins, and the results were evaluated over 48 h. All control subjects and 41 of 46 diabetic patients without local reactions were skin-test negative to insulin.

The effects of hyperinsulinemia on arterial wall and peripheral muscle metabolism in dogs.

Peripheral hyperinsulinemia may be associated with metabolic consequences that could contribute to the high incidence of macrovascular disease in patients with diabetes mellitus. Arterial wall and striated muscle cells were studied in dogs to examine the effect of hyperinsulinemia on the lipid content and on lipogenic and glycolytic enzyme activity. Eight pancreatectomized dogs received segmental pancreatic autografts with venous drainage into the iliac vein.

Aorta and muscle metabolism in pigs with peripheral hyperinsulinaemia.

Peripheral hyperinsulinaemia usually found in conventionally treated Type 1 (insulin-dependent) diabetic patients may have deleterious metabolic effects. We have used a hyperinsulinaemic model to examine intermediary metabolism in two key peripheral tissues, aorta and muscle. Nine pigs were immunized with crystalline insulin.

Metabolism in ischemic muscles before and after treatment with glucose-insulin-potassium infusion.

Arteriosclerosis, arterial thrombosis and emboli in the lower extremities of man result in metabolic disorders in the muscles due to a deficit between oxygen required and oxygen made available. Furthermore, diminished perfusion pressure results in diminished exchange of substrates and electrolytes across the capillary walls. In the muscle cells there is a depression of glycolytic enzyme function and a stimulation of lipid activity, resulting in accumulation of free fatty acids and acidosis within the cells.

Insulin-specific IgE in serum of 67 diabetic patients against human insulin (Novo), porcine insulin, and bovine insulin. Four case reports.

We have investigated the binding of insulin-specific IgE (IgE1) to porcine, bovine, and human insulin (Novo), pancreatic polypeptide, and a-component in serum samples from type I diabetic patients treated with insulin preparations of different purity. Patients treated with porcine or mixed-species purified insulin (monocomponent) did not differ significantly from a nondiabetic control group. Hence, in these groups no IgE1 could be detected against any of the components investigated.

Determination of insulin specific IgE in serum of diabetic patients by solid-phase radioimmunoassay.

A solid-phase assay system for quantitative measurement of insulin specific IgE has been developed. Insulin specific IgE and IgG are bound to insulin covalently coupled to Sepharose particles. After a washing procedure which removes unbound immunoglobulins, 125I-anti-human IgE-rabbit globulin is added to the Sepharose to determine the amount of bound IgE.