Influence of an uremia-associated serum factor on CNS alpha 2-adrenoceptors.
The action of blood serum from uremic rats and chronically hemodialyzed patients was investigated for effects on alpha 2-adrenoceptors labeled with 3H-clonidine. Compared to blood sera of rats and patients with normal kidney function, uremic serum significantly inhibited specific 3H-clonidine binding. In saturation experiments the density and affinity of alpha 2-adrenoceptors for 3H-clonidine was lowered by uremic serum. Heating, or trypsin or lipase treatment of the serum did not affect this phenomenon. The effect of the patient's serum could likewise be demonstrated after hemodialysis treatment. The presence of an allosteric regulating substance for clonidine binding to adrenoceptors could at least partially explain the altered and attenuated action of this drug in renal insufficiency.
Lübbecke
F
F
Center of Internal Medicine, Justus-Liebig University, Giessen, F.R.G.
Steudle
V
V
Wizemann
V
V
D000818:Animals; D001685:Biological Factors / Q000097:blood* / Q000502:physiology; D002540:Cerebral Cortex / Q000378:metabolism*; D003000:Clonidine / Q000378:metabolism; D006801:Humans; D008024:Ligands; D008297:Male; D011897:Random Allocation; D051381:Rats; D011919:Rats, Inbred Strains; D011942:Receptors, Adrenergic, alpha / Q000378:metabolism*; D006435:Renal Dialysis; D014511:Uremia / Q000097:blood*
D001685:Biological Factors; D008024:Ligands; D011942:Receptors, Adrenergic, alpha; D003000:Clonidine