Antinociceptive and lethal effects of intraventricularly administered barium and strontium: antagonism by atropine sulfate or naloxone hydrochlorine.
The intracerebroventricular injection of Ba++ and Sr++ produced naloxone and atropine reversible antinociception as measured by the mouse tail-flick test. Naloxone antagonized the antinociception produced by Ba++ more effectively than atropine (pA2 5.9 vs. 7.0, respectively). Naloxone was less efficient than atropine in blocking lethality. Together these results suggest different mechanisms involved in the production of antinociception and lethality by these ions.
D000700:Analgesics / Q000494:pharmacology*; D000818:Animals; D001285:Atropine / Q000494:pharmacology*; D001464:Barium / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D007276:Injections, Intraventricular; D007928:Lethal Dose 50; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D009270:Naloxone / Q000494:pharmacology*; D010146:Pain; D051381:Rats; D013324:Strontium / Q000037:antagonists & inhibitors / Q000494:pharmacology*
D000700:Analgesics; D001464:Barium; D009270:Naloxone; D001285:Atropine; D013324:Strontium