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In order to determine whether microvascular blood flow is important in the regulation of intra-islet cellular interactions, rat pancreata were isolated and perfused in vitro, both anterogradely or retrogradely, with and without anti-insulin or anti-somatostatin gamma-globulin. Expressed as percent change, anterograde infusion of insulin antibody increased(More)
The present studies were designed to investigate the mechanism of previously-reported nocturnal hyperinsulinemia in the pinealectomized rat. Isolated islets were obtained from anesthetized control, sham-pinealectomized and pinealectomized rats, with 5 rats per surgical groups, during the early dark phase of the daily lightdark cycle. Batches of 3 islets(More)
  • S L Howell, R B Ewart
  • Journal of cell science
  • 1973
Partially purified storage granule fractions obtained from rat anterior pituitaries have been utilized to study some properties of the isolated growth hormone granules during incubation in vitro. The isolated granules showed optimal stability at room temperature in the pH range 5-5-6-5 and dissolved progressively with time at a rate which was unaffected by(More)
Lectins from Agaricus bisporus and Agaricus campestris stimulate insulin and glucagon release from isolated rat islets in the presence of 2 mM glucose. In the case of insulin release, maximal stimulation was observed at lectin concentrations above 58 mug. per milliliter (approximately 1 muM).A. bisporus PHA-B-stimulated insulin release was independent of a(More)
The effects of enflurane upon rate of insulin release from rat pancreatic islets were determined in vitro. A dose-related inhibitory effect of enflurane on glucose-stimulated insulin release was observed with almost complete inhibition being seen when the enflurane concentration in the gas phase was 3.21% (v/v), equivalent to 1.26 mM enflurane in the liquid(More)
The effects of enflurane at a concentration of 4% by volume in the gas phase upon rates of insulin secretion were correlated with islet contents of adenosine 3',5'-cyclic monophosphate (cyclic AMP). At this concentration, enflurane was without effect upon the basal rate of insulin release in the presence of 2 mM glucose. By contrast, the anesthetic led to(More)
1. The release of growth hormone from isolated fragments of rat anterior pituitary tissue incubated in vitro was studied by employing a double-antibody radioimmunoassay. 2. In the absence of added stimuli, two phases of hormone release could be distinguished, an early phase of 2h duration and a subsequent late phase. In the early phase, hormone release was(More)