PubMed Health⌕ Search

Biomedical subjects

M Lamé

Publications and source records attributed to M Lamé.

4 recordsLinked to original sources
PubMed1990

Inbred strain differences in morphine-induced analgesia with the hot plate assay: a reassessment.

Using the hot plate assay of analgesia, several investigators have reported DBA/2J mice to be much more sensitive to morphine and other opioids than C57BL/6J mice using paw-lick as the behavioral end point. In the present studies, we compared DBA/2J, C57BL/6J, and C3H/HeJ mice on two behavioral end points, either (1) the initial response to the hot plate, either a hind paw-lift, paw-shake, or paw-lick, whichever occurred first, or (2) the paw-lick response. In response to either morphine or saline, all three strains showed roughly equivalent latencies to the initial response, but the DBA/2J strain was markedly slow to show paw-lick as a nocifensive response compared to the C57BL/6J strain. As a result, only for the paw-lick response were there significant differences among the three inbred strains in morphine analgesia. Thus, differences in analgesic sensitivity among these strains are largely a function of the behavioral end point used to assess nociception to the hot plate.

Animals↗
PubMed1989

Genetic dissociation of multiple morphine effects among C57BL/6J, DBA/2J and C3H/HeJ inbred mouse strains.

The pattern of sensitivity of mice from three inbred strains were compared on measures of morphine-induced analgesia (hot plate), locomotor activity, hypothermia, Straub tail (muscular rigidity), antidiuresis and constipation. The DBA/2J strain emerged as the most sensitive strain for analgesia, retention of a water load (antidiuresis) and hypothermia. In addition, the DBA/2J mice had lower concentrations of morphine in the brain 30 min after injection and had the lowest Kd and the highest Bmax for naloxone as measured by in vitro receptor binding. In contrast, mice of the C57BL/6J strain were most sensitive when locomotor activity, Straub tail and constipation were measured. The C3H/HeJ mice were generally intermediate in their sensitivity to morphine. The observed strain differences indicate a rather high degree of genetic control for most of the effects studied, however, the low consistency of rank order among the three strains across these measures suggests that the genetically determined mechanisms are largely different between these measures of morphine sensitivity.

Animals↗