H3-receptors control histamine release in human brain.
The regulation of histamine release was studied on slices prepared from pieces of human cerebral cortex removed during neurosurgery and labeled with L-[3H]histidine. Depolarization by increased extracellular K+ concentration induced [3H]histamine release, although to a lesser extent than from rat brain slices. Exogenous histamine reduced by up to 60% the K+-evoked release, with an EC50 of 3.5 +/- 0.5 X 10(-8) M. The H3-receptor antagonists impromidine and thioperamide reversed the histamine effect in an apparently competitive manner and enhanced the K+-evoked release, indicating a participation of endogenous histamine in the release control process. The potencies of histamine and the H3-receptor antagonists were similar to those of these agents at presynaptic H3-autoreceptors controlling [3H]histamine release from rat brain slices. It is concluded that H3-receptors control histamine release in the human brain.
Arrang
J M
JM
Unité 109 de Neurobiologie et Pharmacologie, Centre Paul Broca de l'INSERM, Paris, France.
Devaux
B
B
Chodkiewicz
J P
JP
Schwartz
J C
JC
D002540:Cerebral Cortex / Q000502:physiology*; D006632:Histamine / Q000494:pharmacology; D006636:Histamine Release / Q000187:drug effects; D006801:Humans; D007093:Imidazoles / Q000494:pharmacology; D017446:Impromidine; D010880:Piperidines / Q000494:pharmacology; D011188:Potassium / Q000494:pharmacology; D011968:Receptors, Histamine / Q000187:drug effects / Q000502:physiology*; D018100:Receptors, Histamine H3; D014316:Tritium
D007093:Imidazoles; D010880:Piperidines; D011968:Receptors, Histamine; D018100:Receptors, Histamine H3; D014316:Tritium; D006632:Histamine; D017446:Impromidine; C052075:thioperamide; D011188:Potassium