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An objective of these studies was to test the responsiveness of cold-adapted (8 wk, 5 degrees C) rats to a specific beta-adrenergic agonist. Twenty-four hours after removal from cold, increases in tail skin temperature (Tsk) and colonic temperature (Tco) were measured for 2 h in air at 25 degrees C following subcutaneous (sc) administration of 28, 70 or 136 mug d,l-isoproterenol sulfate dihydrate/kg body wt to restrained male rats. Cold-adapted rats responded to each dose of isoproterenol with greater increases in Tsk than controls. Tco of both groups increased at the two highest doses, but cold-adapted rats showed a greater rise. Thus, cold-adapted rats showed greater metabolic (Tco) and vascular (Tsk) responsiveness to the beta-adrenergic agonist, isoproterenol, than nonadapted controls. No effect of the alpha-adrenergic agonist, phenylephrine (50 or 100 mug/kg body weight, sc), was observed on Tco or Tsk. A second objective was to study the tension developed by aortic smooth muscle rings of cold-adapted and control rats both during stimulation of alpha-adrenergic receptors by norepinephrine and membrane depolarization by KCl. Adaptation to cold air appeared to suppress alpha-adrenergic responsiveness in aortic segments but did not alter responsiveness to KCl. This suggests an unchanged contractile mechanism in aortic rings of cold-adapted rats and a reduced responsiveness either at the level of the alpha-receptor or at a site immediately beyond.
M J Fregly, and
F P Field, and
E L Nelson, and
P E Tyler, and
R Dasler
August 1997,
Physiology & behavior,
M J Fregly, and
F P Field, and
E L Nelson, and
P E Tyler, and
R Dasler
March 1962,
Journal of applied physiology,
M J Fregly, and
F P Field, and
E L Nelson, and
P E Tyler, and
R Dasler
January 2003,
Canadian journal of physiology and pharmacology,
M J Fregly, and
F P Field, and
E L Nelson, and
P E Tyler, and
R Dasler
December 1960,
Federation proceedings,
M J Fregly, and
F P Field, and
E L Nelson, and
P E Tyler, and
R Dasler
January 1966,
Life sciences,
M J Fregly, and
F P Field, and
E L Nelson, and
P E Tyler, and
R Dasler
December 1954,
The American journal of physiology,
M J Fregly, and
F P Field, and
E L Nelson, and
P E Tyler, and
R Dasler
August 1965,
The Journal of pharmacology and experimental therapeutics,
M J Fregly, and
F P Field, and
E L Nelson, and
P E Tyler, and
R Dasler
December 1963,
Arthritis and rheumatism,
M J Fregly, and
F P Field, and
E L Nelson, and
P E Tyler, and
R Dasler
January 2010,
Frontiers in bioscience (Elite edition),
M J Fregly, and
F P Field, and
E L Nelson, and
P E Tyler, and
R Dasler
January 1965,
Medicina et pharmacologia experimentalis. International journal of experimental medicine,
