Prenatal exposure to methamphetamine (METH) increases nociceptive sensitivity in adult rats. As the strong analgesics have high abuse potential and drugs of abuse are known to have analgesic properties, the aim was to study analgesic effect of different psychostimulants in control and prenatally METH-exposed rats. Latencies of withdrawal reflexes of hind limbs and the tail on thermal nociceptive stimuli were repeatedly measured in 15-min intervals after the application of 5 mg/kg s.c. of amphetamine (AMPH), methamphetamine (METH), cocaine (COC), 3,4-methylenedioxymethamphetamine (MDMA) or morphine (MOR). In all groups, AMPH induced on hind limbs stronger analgesia than METH and MDMA whereas COC and MOR were practically without any effect. On the tail, effect of AMPH did not differ from that of MOR. All psychostimulants increased defecation in comparison with MOR and in all groups the number of defecation boluses positively correlated with analgesia of the hind limbs. We did not confirm that prenatal exposure to METH makes adult rats more sensitive either to same drug or to other psychostimulants. The different analgesic potencies of psychostimulants and MOR at different body sites indicate the possible existence of a somatotopic organization of pain inhibition, which is controlled by different mechanisms.

Department of Normal Pathological and Clinical Physiology 3rd Faculty of Medicine Charles University Prague Prague Czech Republic

Citace poskytuje Crossref.org

Impact of altered environment and early postnatal methamphetamine exposure on serotonin levels in the rat hippocampus during adolescence

Influence of Prenatal Methamphetamine Abuse on the Brain

Common mechanisms of pain and depression: are antidepressants also analgesics?