Differential sensitivity to dexamethasone influence on morphine antinociception in two different strains of mice: DBA/2J and C57BL/6.
The influence of dexamethasone on morphine antinociception in two different strains of mice (DBA/2J and C57BL/6) was studied by using the hot plate test. Intracerebroventricular (i.c.v.) injection of dexamethasone induced a significant increase of nociceptive response in DBA/2J but not in C57BL/6 mice. Intraperitoneal (i.p.) injection of dexamethasone did not modify nociceptive response both in DBA/2J and C57BL/6 mice. Both i.c.v. and i.p. injection of dexamethasone did not modify morphine antinociception in DBA/2J mice whereas a significant reduction of morphine antinociception was observed in C57BL/6 mice after i.p. injection of dexamethasone. These results suggest that the use of different genetic strains may provide an useful approach for studying dexamethasone-morphine antinociception interaction.
Department of Experimental Pharmacology, University of Naples, Italy.
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Capasso
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Di Giannuario
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Loizzo
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Pieretti
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Sorrentino
D000818:Animals; D003907:Dexamethasone / Q000008:administration & dosage / Q000494:pharmacology*; D007276:Injections, Intraventricular; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D009020:Morphine / Q000037:antagonists & inhibitors*; D010147:Pain Measurement / Q000187:drug effects*; D017450:Receptors, Opioid, mu / Q000187:drug effects; D013045:Species Specificity; D013997:Time Factors
D017450:Receptors, Opioid, mu; D009020:Morphine; D003907:Dexamethasone