Noradrenaline- and time-dependent changes in neocortical alpha 2- and beta 1-adrenoceptor binding in dorsal noradrenergic bundle-lesioned rats.
A 6-hydroxydopamine-induced lesion of the dorsal noradrenergic bundle (DNB) in rats markedly decreased neocortical noradrenaline concentration (NNC) by 72-100% as measured 1, 3 and 13 months after the lesioning procedure. The concomitant assessment of neocortical alpha 2- and beta 1-adrenoceptor binding (NAAB and NBAB, respectively) usually indicated significant increases of 25-72% for these two variables. There were, however, cases of unchanged NAAB and NBAB which presumably reflected an incomplete DNB lesion and a consequent time-related, partial recovery of NNC. The results emphasize the potential for long-term sequelae of the DNB lesion, and the existence of a critical NNC threshold (approximately 10-30% of control NNC values) which modulates postsynaptic alpha 2- and beta 1-adrenoceptor density.
Dooley
D J
DJ
Gödecke Research Institute, Freiburg, F.R.G.
Jones
G H
GH
Robbins
T W
TW
D000818:Animals; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology; D003000:Clonidine / Q000031:analogs & derivatives / Q000493:pharmacokinetics; D004082:Dihydroalprenolol / Q000493:pharmacokinetics; D006892:Hydroxydopamines; D007093:Imidazoles / Q000493:pharmacokinetics; D008297:Male; D009638:Norepinephrine / Q000378:metabolism*; D016627:Oxidopamine; D051381:Rats; D011942:Receptors, Adrenergic, alpha / Q000378:metabolism*; D011943:Receptors, Adrenergic, beta / Q000378:metabolism*; D013997:Time Factors
D006892:Hydroxydopamines; D007093:Imidazoles; D011942:Receptors, Adrenergic, alpha; D011943:Receptors, Adrenergic, beta; D004082:Dihydroalprenolol; C016986:apraclonidine; D016627:Oxidopamine; C049763:CGP 20712A; D003000:Clonidine; D009638:Norepinephrine