Morphine induced increases in the incorporation of 3H-thymidine into brain striatal DNA.
3H-thymidine uptake into DNA fractions of rat brain regions was measured following in vivo administration of (methyl-3H)-thymidine and morphine. Acute morphine administration (10 mg/kg; 30 min prior to 3H-thymidine) increased incorporation of 3H-thymidine into DNA of rat striatum. This effect was antagonized by naloxone (1 mg/kg). Further, the observed change in incorporation of 3H-thymidine into DNA in striatum could not be accounted for by differences in the local availability of the label in morphinized rats. An autoradiographic study revealed that the 3H-thymidine was localized in nuclei in cells of the sub-ependymal layer lining the lateral ventricles, an area of glial cell proliferation in adult rats. No change in 3H-thymidine incorporation into DNA was observed in any area of the brain in morphine-addicted rats or in rats undergoing naloxone-precipitated withdrawal. The results indicate that opiates may induce permanent anatomical changes in the brain, including alterations of neuroglial interactions.
D000818:Animals; D001345:Autoradiography; D003342:Corpus Striatum / Q000187:drug effects* / Q000378:metabolism; D004247:DNA / Q000096:biosynthesis*; D004805:Ependyma / Q000187:drug effects / Q000378:metabolism; D008297:Male; D009020:Morphine / Q000494:pharmacology*; D009270:Naloxone / Q000494:pharmacology; D051381:Rats; D013936:Thymidine / Q000378:metabolism*
D009270:Naloxone; D009020:Morphine; D004247:DNA; D013936:Thymidine