Prodynorphin, proenkephalin and kappa opioid receptor mRNA responses to acute "binge" cocaine.
Previous studies showed that preprodynorphin (ppDyn) mRNA increases in caudate-putamen while kappa opioid receptor (KOR) mRNA decreases in substantia nigra after 3 and 14 days "binge" cocaine. To further characterize opioid mRNA responses, rats were administered: saline; 1 day cocaine followed by 1 day saline; 1 day cocaine; or 2 days cocaine. ppDyn mRNA in caudate-putamen increased in both groups receiving cocaine on the final day compared to groups receiving saline. Preproenkephalin (ppEnk) mRNA in caudate-putamen increased, and KOR mRNA in substantia nigra decreased, after 2 days of cocaine. Thus ppDyn mRNA is elevated acutely by cocaine, while ppEnk and KOR mRNAs show a significant response only on the second day of "binge" cocaine.
Spangler
R
R
Laboratory of the Biology of Addictive Diseases, Rockefeller University, New York, NY 10021, USA.
Zhou
Y
Y
Maggos
C E
CE
Schlussman
S D
SD
Ho
A
A
Kreek
M J
MJ
D000818:Animals; D003042:Cocaine / Q000494:pharmacology*; D004745:Enkephalins / Q000494:pharmacology*; D008297:Male; D011498:Protein Precursors / Q000494:pharmacology*; D012333:RNA, Messenger / Q000378:metabolism*; D051381:Rats; D011916:Rats, Inbred F344; D017473:Receptors, Opioid, kappa / Q000187:drug effects* / Q000378:metabolism*; D013997:Time Factors
D004745:Enkephalins; D011498:Protein Precursors; D012333:RNA, Messenger; D017473:Receptors, Opioid, kappa; C029992:proenkephalin; C033660:preproenkephalin; D003042:Cocaine