This work was carried out on 42 albino rats to study the effect of the
C.C.B ( verapamil ) and H2 receptor antagonist ( ranitidine ) on modulation
of pain threshold and morphine an.tinocicept tiue action. Our study
demonstrated that C.C.B (verapamil) has antinociceptive action to thermal
stimulation indicating that Ca + is an important mediator in pain pathway.
However pretreatment of rats with a single Intraperitoneal dose (LP) of
C.C.B neither _p otentiates nor inhibited the analgesic activity of morphine.
On the other hand C.C.B (veraparnil) decreased the antinociceptive action
of morphine when it was given in a single (LP) dose after morphine injection.
The H2 receptor antagonist (rantidirte) induced antinociceptive activity
which may be through its binding to opiate receptors as the opiate antagonist
naloxone blocked this effect. Pretreatment of rats with rartitidine
greatly potentiated the analgesic activity of morphine, a result which may
be of value in reducing the dose of morphine and hence its side effects. |
