Delivery is a stressful and risky event menacing the newborn. The mother-dependent respiration has to be replaced by autonomous pulmonary breathing immediately after delivery. If delayed, it may lead to deficient oxygen supply compromising survival and development of the central nervous system. Lack...

The role of alpha 1 receptors in antinociception was investigated in the formalin test, a well established test of tonic pain. The effect of systemic injections of selective alpha 1-adrenergic agonists (phenylephrine and methoxamine), a mixed alpha agonist selective for alpha 2 receptors (ST-91), an...

Dose-response curves for clonidine-produced analgesia in rats were constructed using the tail-flick and formalin tests. Subsequently, the relative role of alpha 1 and alpha 2 receptors in clonidine analgesia in each of these tests was determined using systemic administration of vehicle controls, tol...

Previous reports have suggested that tolerance to the antinociceptive effects of morphine does not develop in the formalin test. To re-examine these findings, morphine was administered via multiple injections or continuous infusion from 0 to 4 days prior to testing with either the formalin or tail-f...

In previous studies from this laboratory it was found that dibutanoylmorphine (DBM) was more potent than morphine as an analgesic in rats and that it was less active than acetyl esters of morphine on behaviour. As DBM is a morphine prodrug, the aim of this work was to determine if rat brain homogena...