Summary
Hind-limb perfusion was used to investigate alterations of alpha and beta receptor-mediated
metabolic effects in cold-adapted (CA) rats. The response to beta receptor stimulation
by isoproterenol in the isolated hind-limbs of CA rats was slightly diminished. Oxygen
consumption and lactate production were reduced in CA rats after beta receptor stimulation.
Noradrenalin infusion caused less vasoconstriction in CA rats than in the controls
(CO). Desensitization of alpha and beta receptors due to chronic sympathetic overstimulation
may be the underlying cause of these observations.
Compared with the controls, metabolism was enhanced in perfused hind-limbs of CA rats
with an active nervous system. Decreased vascular resistance due to the lower perfusion
pressure in CA rats might contribute to this increased metabolism.
Key-Words
Cold Adaptation
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Hind-Limb Perfusion
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Catecholamines
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Adrenergic Receptors
