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Comparative methods for inducing and measuring non-shivering thermogenesis in newborn lambs

Published online by Cambridge University Press:  02 September 2010

J. Slee ,
S. P. Simpson  and
S. B. Wilson
J. Slee
Affiliation:
AFRC Institute of Animal Physiology and Genetics Research†, Edinburgh Research Station, West Mains Road, Edinburgh EH9 3JQ
S. P. Simpson
Affiliation:
AFRC Institute of Animal Physiology and Genetics Research†, Edinburgh Research Station, West Mains Road, Edinburgh EH9 3JQ
S. B. Wilson
Affiliation:
AFRC Institute of Animal Physiology and Genetics Research†, Edinburgh Research Station, West Mains Road, Edinburgh EH9 3JQ
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Abstract

Thirty-one newborn lambs were allocated to four treatments involving subcutaneous or slowly administered intravenous injections of noradrenaline (a natural predominantly a-agonist) or isoprenaline (a synthetic pure ($-agonist). The thermogenic effect of these treatments, attributed to brown adipose tissue, was assessed by changes in metabolic rate and rectal temperature. The objective was to define the optimum treatment for studying genetic variation between lambs in the thermogenic activity of brown adipose tissue. After all treatments, metabolic rate increased significantly by about 7 W/kg to a peak averaging 2·3 times the resting metabolic rate. Rectal temperature increased significantly by about 1°C. Both drugs administered at 150 [ig/kg were similar in potency with noradrenaline producing slightly, but not significantly, greater responses; subcutaneous injections gave significantly larger and more prolonged responses than intravenous injections. Subcutaneous isoprenaline produced the longest sustained response with peak metabolism difficult to define. Subcutaneous noradrenaline injections provided the simplest satisfactory treatment for large scale experiments.

Type
Research Article
Information
Animal Production , Volume 45 , Issue 1 , August 1987 , pp. 61 - 67
Copyright
Copyright © British Society of Animal Science 1987

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