Effects of morphine and (D-Ala, Met)-enkephalinamide on 45Ca-uptake to rat brain striatal slices.
Effects of morphine and (D-Ala, Met)-enkephalinamide on 45Ca-uptake to rat striatal slices were examined. While morphine didn't give any effect on 45Ca-uptake to striatal slices in normal Krebs-Ringer solution, it inhibited K+ (40 mM)-stimulated 45Ca-uptake to slices. In high K+ medium, 45Ca-uptake was enhanced to 170% and this was reduced to 147 and 137% by 10(-5) and 10(-4) M morphine, respectively. Furthermore, the effect of morphine was antagonized by 10(-5) M naloxone. (D-Ala, Met)-enkephalinamide (10(-4) M) also inhibited K+-stimulated 45Ca-uptake to the slices to the same extent as was observed by morphine. K+-stimulated 45Ca-uptake to striatal slices obtained from chronically morphine administered rat (6 mg/kg, twice/day, 7 days) was not inhibited by morphine.
D000818:Animals; D001693:Biological Transport, Active / Q000187:drug effects; D002118:Calcium / Q000378:metabolism*; D003342:Corpus Striatum / Q000187:drug effects* / Q000378:metabolism; D004744:Enkephalin, Methionine / Q000031:analogs & derivatives* / Q000494:pharmacology; D066298:In Vitro Techniques; D009020:Morphine / Q000494:pharmacology*; D011188:Potassium / Q000494:pharmacology; D051381:Rats
D004744:Enkephalin, Methionine; C022118:enkephalinamide-Met, Ala(2)-; D009020:Morphine; D011188:Potassium; D002118:Calcium