The effect of aging on the response of striatal preproenkephalin and preprotachykinin mRNA contents to chronic haloperidol treatment in rats: measurement by solution-hybridization RNase protection assay.
The preproenkephalin (PPeK) and preprotachykinin (PPT) mRNA contents in 3-, 10- and 23-month-old rats in the striatum were measured by solution hybridization-RNase protection assay after 3 weeks of haloperidol injection. Haloperidol increased striatal PPek mRNA. There was no age-related difference in the response of striatal PPeK mRNA to chronic haloperidol treatment. The PPT mRNA decreased by 21% after the haloperidol treatment in young rats only. Meanwhile, age decreased the PPT mRNA by 27 and 24% in 10- and 23-month-old rats, respectively. It is concluded that there is a difference in the effects of aging on the response of PPek and PPT mRNA contents to haloperidol and that the loss of PPT mRNA response in 10- and 23-month-old rats might be due to the change of dopamine system of the striatum in these rats.
Lau
S M
SM
Department of Physiology, Faculty of Medicine, The University of Hong Kong, China.
Tang
F
F
D000375:Aging; D000818:Animals; D003342:Corpus Striatum / Q000187:drug effects / Q000378:metabolism*; D004745:Enkephalins / Q000096:biosynthesis*; D006220:Haloperidol / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D011498:Protein Precursors / Q000096:biosynthesis*; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D015320:Tachykinins / Q000096:biosynthesis*
D004745:Enkephalins; D011498:Protein Precursors; D012333:RNA, Messenger; D015320:Tachykinins; C044206:preprotachykinin; C033660:preproenkephalin; D006220:Haloperidol