Calcium-dependent histidine and histamine release from superfused synaptosomes.
The release of radioactive histidine and histamine was studied in a superfusion system by using guinea pig synaptosomes which were preloaded with 3H-histidine. Depolarization by 50 mM K+ induced a simultaneous release of histidine and histamine. The stimulated release of both of these substances was diminished when calcium was removed. The calcium-dependency of histamine release, previously demonstrated in brain slices, was confirmed using synaptosomes. It was also demonstrated that potassium-induced histidine release from guinea pig synaptosomes under superfusion conditions is at least partially calcium-dependent.
Department of Pharmacology and Toxicology, University of Kuopio, Finland.
T
T
Tikkanen
O
O
Raatikainen
L
L
Tuomisto
D000818:Animals; D002118:Calcium / Q000502:physiology*; D006168:Guinea Pigs; D006636:Histamine Release / Q000187:drug effects*; D006639:Histidine / Q000378:metabolism*; D066298:In Vitro Techniques; D008297:Male; D011188:Potassium / Q000494:pharmacology; D013574:Synaptosomes / Q000187:drug effects / Q000378:metabolism*
D006639:Histidine; D011188:Potassium; D002118:Calcium