Pertussis toxin treatment counteracts intramembrane interactions between neuropeptide Y receptors and alpha 2-adrenoceptors.
The effect of intracerebroventricular injections of pertussis toxin were investigated on the neuropeptide Y-induced modulation of alpha 2-adrenoceptor binding in membranes from the dorsomedial medulla oblongata of the rat. Concentration-response experiments showed that neuropeptide Y reduced the binding affinity of the alpha 2-agonist, p-[3H]aminoclonidine, with a maximal effect of 30% at 3-30 nM. Pertussis toxin treatment (10 micrograms, 24 h) counteracted this modulation, without reducing the binding of neuropeptide Y to its own receptor. The results indicate that pertussis toxin-sensitive G-proteins are essential for the mediation of the intramembrane interaction between neuropeptide Y receptors and alpha 2-adrenoceptors.
Von Euler
G
G
Department of Histology and Neurobiology, Karolinska Institute, Stockholm, Sweden.
Fuxe
K
K
Van der Ploeg
I
I
Fredholm
B B
BB
Agnati
L F
LF
D000246:Adenosine Diphosphate Ribose / Q000378:metabolism; D000818:Animals; D001345:Autoradiography; D066298:In Vitro Techniques; D007276:Injections, Intraventricular; D007700:Kinetics; D008297:Male; D008526:Medulla Oblongata / Q000187:drug effects / Q000378:metabolism; D008566:Membranes / Q000187:drug effects / Q000378:metabolism; D037342:Pertussis Toxin; D051381:Rats; D011919:Rats, Inbred Strains; D011942:Receptors, Adrenergic, alpha / Q000187:drug effects / Q000378:metabolism*; D017476:Receptors, Neuropeptide Y; D017981:Receptors, Neurotransmitter / Q000378:metabolism*; D010566:Virulence Factors, Bordetella / Q000008:administration & dosage / Q000494:pharmacology*
D011942:Receptors, Adrenergic, alpha; D017476:Receptors, Neuropeptide Y; D017981:Receptors, Neurotransmitter; D010566:Virulence Factors, Bordetella; D000246:Adenosine Diphosphate Ribose; D037342:Pertussis Toxin