AbstractHistamine releases catecholamines and opioids in primary cultured bovine adrenal medullary (BAM) chromaffin cells. We have studied whether histamine is synthesized and localized in BAM cells, and whether it can be released upon activation with secretagogues. In BAM cells histamine is immunohistochemically co‐localized with tyrosine hydroxylase in 45 ± 8 of all cells. Only histamine immunoreactivity was observed in 8 ± 2 of all BAM cells. No mast‐cell‐like cells were observed in our system. Histamine can be released from BAM cells by high potassium (56 mM K+) in a calcium‐dependent manner. Compound 48/80 did not release histamine from BAM cells but nicotine caused a dose‐dependent liberation of the amine. Cultured BAM cells have histidine decarboxylase activity which is inhibited by α‐fluoromethylhistidine. These results indicate that endogenous histamine is synthesized, stored and released in BAM chromaffin
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