Recovery of β-receptors and adenylate cyclase from desensitization induced by short term heat exposure in rat parotid glands

Abstract

1. 1. The recovery of rat parotid β-adrenergic receptors (β-AR) and adenylate cyclase (AC) from heat (33°C)-induced desensitization was studied. 2. 2. Down-regulated cell surface β-AR and AC activity in response to isoprenaline (IPR) returned to the control level 120 hr after the termination of heat exposure. 3. 3. However, β-AR in parotid crude membranes increased over the control level for 48–120 hr. 4. 4. Coupling between β-AR and G protein(s) was attenuated at 120 hr. 5. 5. These data suggest that β-AR on the cell surface, but not those internalized, can transduce biological responses.