Phorbol ester stimulates catecholamine synthesis in isolated bovine adrenal medullary cells.
In isolated bovine adrenal medullary cells, the phorbol ester 12-O-tetradecanoyl phorbol 13-acetate (TPA), an activator of protein kinase C, stimulated [14C]catecholamine synthesis from [14C]tyrosine, but not from [14C]DOPA. This stimulatory effect of TPA on [14C]catecholamine synthesis was not dependent upon extracellular Ca2+, and TPA did not affect the uptake of 45Ca2+ or the release of catecholamine by the cells. TPA also did not affect the intracellular cyclic AMP (cAMP) level. 4 alpha-Phorbol 12, 13-didecanoate, which is not an activator of protein kinase C, did not stimulate the synthesis of [14C]catecholamine from [14C]tyrosine. The stimulatory effect of TPA on [14C]catecholamine synthesis was additive with that of carbamylcholine, but not with that of dibutyryl cAMP (DB-cAMP). From these results, it was suggested that protein kinase C is involved in the regulation of tyrosine hydroxylase activity and that this regulatory mechanism might be similar to that involving cAMP.
Houchi
H
H
Nakanishi
A
A
Uddin
M M
MM
Ohuchi
T
T
Oka
M
M
D000313:Adrenal Medulla / Q000187:drug effects / Q000378:metabolism*; D000818:Animals; D003994:Bucladesine / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D002217:Carbachol / Q000494:pharmacology; D002395:Catecholamines / Q000096:biosynthesis*; D002417:Cattle; D005576:Colforsin; D000242:Cyclic AMP / Q000378:metabolism; D004224:Diterpenes / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects; D066298:In Vitro Techniques; D010704:Phorbols / Q000494:pharmacology*; D011493:Protein Kinase C; D011494:Protein Kinases / Q000502:physiology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*; D014443:Tyrosine / Q000378:metabolism
D002395:Catecholamines; D004224:Diterpenes; D010704:Phorbols; D005576:Colforsin; D014443:Tyrosine; D003994:Bucladesine; D002217:Carbachol; D000242:Cyclic AMP; D011494:Protein Kinases; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate; D002118:Calcium