Wanda L Snead

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Our aim was to determine whether complete hepatic denervation would affect the hormonal response to insulin-induced hypoglycemia in dogs. Two weeks before study, dogs underwent either hepatic denervation (DN) or sham denervation (CONT). In addition, all dogs had hollow steel coils placed around their vagus nerves. The CONT dogs were used for a single study(More)
Glucagon may regulate FFA metabolism in vivo. To test this hypothesis, six healthy male volunteers were infused with somatostatin, to inhibit endogenous hormone secretion, and insulin, glucagon, and GH to replace endogenous secretion of these hormones. In the hypoglucagonemia experiments, the glucagon infusion was omitted, and in the hyperglucagonemic(More)
The infusion of 5-aminoimidazole-4-carboxamide-1-beta-D-ribofuranoside (AICAR) causes a rise in tissue concentrations of the AMP analog 5-aminoimidazole-4-carboxamide-1-beta-D-ribofuranotide (ZMP), which mimics an elevation of cellular AMP levels. The purpose of this work was to determine the effect of raising hepatic ZMP levels on hepatic insulin action in(More)
The role of plasma glucose in the regulation of lipid metabolism in humans, independent of associated changes in hormone concentrations, is controversial. Therefore we examined the role of glucose in the regulation of lipolysis and free fatty acid (FFA) reesterification in six healthy lean male volunteers. Blood glucose concentration was clamped at either 5(More)
We evaluated the effect of chronic (3 wk) subcutaneous treatment with progesterone and estradiol (PE; producing serum levels observed in the 3rd trimester of pregnancy) or placebo (C) on hepatic and whole body insulin sensitivity and response to hypoglycemia in conscious, overnight-fasted nonpregnant female dogs, using tracer and arteriovenous difference(More)
Fuel and energy homeostasis was examined in six male volunteers during a 60-h fast by using a combination of isotopic tracer techniques ([3-3H]glucose, [2H5]glycerol, [1-14C]palmitate, and L-[1-13C]leucine) and indirect calorimetry. Plasma glucose concentration and hepatic glucose production decreased by 30% with fasting (5.2 +/- 0.1 to 3.8 +/- 0.2 mmol/L(More)
UNLABELLED Whether glucagon-like peptide-1 (GLP-1) has insulin-independent effects on glucose disposal in vivo was assessed in conscious dogs by use of tracer and arteriovenous difference techniques. After a basal period, each experiment consisted of three periods (P1, P2, P3) during which somatostatin, glucagon, insulin, and glucose were infused. The(More)
Arteriovenous difference and tracer ([3-(3)H]glucose) techniques were used in 42-h-fasted conscious dogs to identify any insulin-like effects of intraportally administered glucagon-like peptide 1-(7-36)amide (GLP-1). Each study consisted of an equilibration, a basal, and three 90-min test periods (P1, P2, and P3) during which somatostatin, intraportal(More)
Whether glucagon-like peptide (GLP)-1 requires the hepatic portal vein to elicit its insulin secretion-independent effects on glucose disposal in vivo was assessed in conscious dogs using tracer and arteriovenous difference techniques. In study 1, six conscious overnight-fasted dogs underwent oral glucose tolerance testing (OGTT) to determine target GLP-1(More)
It has been demonstrated in the conscious dog that portal glucose infusion creates a signal that increases net hepatic glucose uptake and hepatic glycogen deposition. Experiments leading to an understanding of the mechanism by which this change occurs will be facilitated if this finding can be reproduced in the rat. Rats weighing 275-300 g were implanted(More)