An inhibitor of cerebral uptake of noradrenaline in jaundiced blood plasma.
The permeability of the blood-brain barrier to noradrenaline was estimated in rats with bile duct ligation by intracarotid injection of [14C]-L-noradrenaline, 3H2O, and [113mIn]ethylene diamine tetraacetate (EDTA) under pentobarbitone anaesthesia. Brain uptake of [14C]noradrenaline was expressed as a percentage of that of 3H2O (brain uptake index, BUI) and corrected for the "blood background" by the 113mIn. The BUI of noradrenaline (1.20 +/- 0.19) was not increased in jaundice (0.78 +/- 0.18). The capacity of oxygenated homogenates of rat brain to remove noradrenaline was measured. The presence of jaundiced plasma always caused a substantial suppression of noradrenaline removal. No effect of jaundice on specific radioactive assays for catechol-O-methyl transferase (COMT) or monoamine oxidase (MAO) could be demonstrated.
D000818:Animals; D001812:Blood-Brain Barrier; D001921:Brain / Q000378:metabolism*; D002394:Catechol O-Methyltransferase / Q000378:metabolism; D007565:Jaundice / Q000097:blood / Q000378:metabolism*; D008297:Male; D008995:Monoamine Oxidase / Q000378:metabolism; D009638:Norepinephrine / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains
D008995:Monoamine Oxidase; D002394:Catechol O-Methyltransferase; D009638:Norepinephrine