In vivo adaptive control of beta-receptors and adenylate cyclase during short-term heat exposure in rat parotid glands.
1. Adaptation of beta-adrenergic receptors (beta-AR) and adenylate cyclase (AC) in rat parotid glands during short-term heat exposure (33 degrees C) were studied. 2. Heat exposure reduced AC activity in response to isoproterenol (IPR). 3. The number of beta-AR on the cell surface significantly increased after 24 hr but returned to control level after 48 hr. 4. IPR-induced [3H]GDP release was significantly reduced throughout exposure. 5. The data suggest that the major factor which results in the desensitization of AC during short-term heat exposure is a blunted coupling between beta-AR and GTP binding protein(s).
Department of Pharmacology, Tokyo College of Pharmacy, Japan.
H
H
Fujinami
T
T
Komabayshi
T
T
Izawa
T
T
Nakamura
K
K
Suda
M
M
Tsuboi
D000222:Adaptation, Physiological; D000262:Adenylyl Cyclases / Q000378:metabolism / Q000502:physiology*; D000818:Animals; D002712:Chlorides; D005576:Colforsin / Q000494:pharmacology; D019204:GTP-Binding Proteins / Q000502:physiology; D006153:Guanosine Diphosphate / Q000378:metabolism; D006160:Guanosine Triphosphate / Q000494:pharmacology; D006358:Hot Temperature; D007545:Isoproterenol / Q000494:pharmacology; D008297:Male; D008345:Manganese / Q000494:pharmacology; D017895:Manganese Compounds; D008566:Membranes / Q000378:metabolism; D009638:Norepinephrine / Q000378:metabolism; D010306:Parotid Gland / Q000378:metabolism / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D011943:Receptors, Adrenergic, beta / Q000502:physiology*; D009435:Synaptic Transmission / Q000502:physiology; D013997:Time Factors
D002712:Chlorides; D017895:Manganese Compounds; D011943:Receptors, Adrenergic, beta; D006153:Guanosine Diphosphate; D005576:Colforsin; D008345:Manganese; D006160:Guanosine Triphosphate; D019204:GTP-Binding Proteins; D000262:Adenylyl Cyclases; D007545:Isoproterenol; C025340:manganese chloride; D009638:Norepinephrine