Histamine activates proenkephalin A mRNA but not phenylethanolamine N-methyltransferase mRNA expression in cultured bovine adrenal chromaffin cells.
The effects of histamine on the regulation of proenkephalin A (ProEnk A) and phenylethanolamine N-methyltransferase (PNMT) mRNA expression were examined in cultures of bovine adrenal chromaffin cells. Prolonged incubation with histamine resulted in a concentration-dependent increase in the levels of ProEnk A mRNA with little effect on the levels of PNMT mRNA. The activation of ProEnK A mRNA by histamine followed a slow time course, reaching 2-3 fold basal levels after 48 h incubation. This activation was antagonized by the H1-antagonist mepyramine but not by the H2-antagonist cimetidine indicating involvement of H1-histamine receptors. The histamine-induced activation of ProEnK mRNA was blocked by the RNA synthesis inhibitor actinomycin D, suggesting that the novo synthesis of ProEnkA mRNA is a requirement for activation. In the presence of the calcium channel blocker D600, the histamine-induced increase in ProEnk A mRNA was greatly reduced, though not abolished. Prolonged incubation with histamine also caused a substantial release of catecholamines and opioid peptides from these cells. These results suggest that the synthesis and release of opioid peptides is controlled by histamine via H1-receptors. The differential effects of histamine on ProEnk A mRNA and PNMT mRNA expression suggest that different regulatory mechanisms are called upon to regulate the synthesis of opioid peptides and adrenaline in response to stimulation of the chromaffin cells.
Wan
D C
DC
Department of Biochemistry, University of Melbourne, Parkville, Victoria, Australia.
Marley
P D
PD
Livett
B G
BG
D000311:Adrenal Glands / Q000166:cytology / Q000201:enzymology / Q000378:metabolism*; D000818:Animals; D002395:Catecholamines / Q000378:metabolism; D002417:Cattle; D002838:Chromaffin System / Q000166:cytology / Q000201:enzymology / Q000378:metabolism*; D004745:Enkephalins / Q000096:biosynthesis*; D004789:Enzyme Activation; D006632:Histamine / Q000494:pharmacology*; D006900:Hydroxylation; D015345:Oligonucleotide Probes; D010625:Phenylethanolamine N-Methyltransferase / Q000096:biosynthesis* / Q000235:genetics; D011498:Protein Precursors / Q000096:biosynthesis*; D012333:RNA, Messenger / Q000032:analysis / Q000096:biosynthesis* / Q000235:genetics; D014443:Tyrosine / Q000378:metabolism
D002395:Catecholamines; D004745:Enkephalins; D015345:Oligonucleotide Probes; D011498:Protein Precursors; D012333:RNA, Messenger; C029992:proenkephalin; D014443:Tyrosine; D006632:Histamine; D010625:Phenylethanolamine N-Methyltransferase