Induction of physical dependence on morphine and genetic analysis of morphine withdrawal signs in mice
Suzuki, T.; Otani, K.; Misawa, M.
Arukoru Kenkyu to Yakubutsu Izon 23(3): 258-267
1988
ISSN/ISBN: 0389-4118 PMID: 3207410 Document Number: 307949
Male ICR mice were treated for 24 hr with slow release emulsion (SRE) of morphine (300, 500 and 1000 mg/kg). The morphine-treated mice manifested body weight loss, jumping, diarrhea, body shakes and ptosis after naloxone injection. Genetic analysis of withdrawal signs from morphine in C57BL/6 (P1), DBA/2 (P2), their F1 hybrid and backcross populations (B1 and B2) was examined. Lethal effect of morphine was the highest in C57BL/6 (P1) of all the populations tested. All the populations showed morphine withdrawal signs, such as body weight loss, jumping, diarrhea, body shakes and ptosis, after naloxone injection. The ranking of the incidence of naloxone-induced jumping was as follows: P1 > B1 > F1 > B2 > P2, suggesting that the naloxone-induced jumping may be strongly influenced by genetic factors. But, there was no relationship between other withdrawal signs and populations.