Effects of thyroid status on plasma adrenaline and noradrenaline concentrations in sheep during acute and chronic cold exposure
- 1 June 1978
- journal article
- research article
- Published by Canadian Science Publishing in Canadian Journal of Physiology and Pharmacology
- Vol. 56 (3), 490-496
- https://doi.org/10.1139/y78-073
Abstract
In the first of two experiments, plasma concentrations of adrenaline (A), noradrenaline (NA), and glucose were determined in intact sheep and in surgically thyroidectomized sheep treated intramuscularly with either 0.125 or 0.25 mg triiodothyronine (T3) per day. On day 28 of exposure to temperatures of 22–25 or 2–5 °C, overall mean plasma concentrations of A were 0.07 and 0.15 ng/ml, respectively, and of NA were 0.30 and 0.45 ng/ml, respectively. Plasma A concentrations were higher in intact compared with thyroidectomized sheep on T3 therapy. Plasma glucose concentrations were increased by exposure to 2–5 °C and by T3 treatment. In a second experiment thyroidectomized sheep were kept at 22–26 °C and were either T3 treated (0.07 mg T3/day, im) or untreated. After 3 weeks, mean concentrations in the untreated sheep before acute cold and during the last hour of cold exposure (−23 °C) were, respectively: for A, 0.09 and 0.47 ng/ml; for NA, 0.46 and 3.15 ng/ml; and for glucose, 62.1 and 122.1 mg/100 ml. In T3-treated sheep the mean concentrations before and during cold were, respectively: for A, 0.07 and 0.22 ng/ml; for NA, 0.30 and 1.71 ng/ml; and for glucose, 59.6 and 82.3 mg/100 ml. The untreated sheep showed greater increases in plasma concentrations of A, NA, and glucose and in hematocrit values than T3-treated sheep, but had slightly smaller increases in metabolic rate, greater decreases in rectal temperature, and similar heart rates during cold exposure.This publication has 11 references indexed in Scilit:
- Studies on the Relationship between Thyroid Function, Cold Acclimation and Retention Time of Digesta in SheepJournal of Animal Science, 1977
- Plasma norepinephrine responses of man in cold waterJournal of Applied Physiology, 1977
- Red blood cell catechol O-methyltransferase activity in thyroid dysfunctionCanadian Journal of Physiology and Pharmacology, 1977
- Catecholamine Metabolism in Thyroid Disease. II. Norepinephrine Secretion Rate in Hyperthyroidism and HypothyroidismJournal of Clinical Endocrinology & Metabolism, 1977
- Effects of handling, decapitation, anesthesia, and surgery on plasma noradrenaline levels in the white ratCanadian Journal of Physiology and Pharmacology, 1977
- EFFECTS OF COLD ON DIGESTIBILITY, RETENTION TIME OF DIGESTA, RETICULUM MOTILITY AND THYROID HORMONES IN SHEEPCanadian Journal of Animal Science, 1976
- Plasma catecholamine concentrations in hyperthyroidism and hypothyroidismMetabolism, 1976
- EFFECTS OF PROLONGED COLD AND THE OUTDOOR WINTER ENVIRONMENT ON APPARENT DIGESTIBILITY IN SHEEP AND CATTLECanadian Journal of Animal Science, 1976
- Temperature-Induced Changes in Metabolism and Body Weight of Cattle (Bos taurus)Canadian Journal of Physiology and Pharmacology, 1975
- Studies of the Importance of the Thyroid and the Sympathetic System in the Defence to Cold of the GoatActa Physiologica Scandinavica, 1967