| dc.description.abstract | The aims of the experiments were to study pain
mechanisms and behaviour in two species of mole-rats, the
naked mole-rat (Heterocepha/us g/aber) and the root-rat
mole-rat (Tachyoryctes sp/endens). Two opioids (pethidine
and codeine), three. non-steroidal anti-inflammatory drugs
(paracetamol, acetylsalicylic acid (ASA) and indomethacin)
and two steroid anti-inflammatory drugs (dexamethasone
and hydrocortisone) were used in this study. The hot-plate
test used in this study was set at a temperature of 600 C.
The two species of mole-rats were kept under controlled
laboratory conditions.
In both species of mole-rats the opiates used
(pethidine: 10, 20 or 30 mg/kg, codeine: 15, 25, 35 or 50
mg/kg) had no antinociceptive effect but instead induced a
dose-dependent reduction in response latency.
Administration of pethidine or codeine also induced
aggressive behaviour and sensorimotor effects in the naked
mole-rat. The change in behaviour was not observed in the
root-rat mole-rat after pethidine administration.
Paracetamol (400 mg/kg) and indomethacin (40 or 50 mg/kg)
caused a significant increase in stepping latency in the
naked mole-rat. Lower doses of these drugs had no
antinociceptive effect. No anti nociceptive effect of either
acetylsalicylic acid (200, 400 or 600 mg/kg),
hydrocortisone (75, 150 or 225 mg/kg) or dexamethasone
(10, 20 or 30 mg/kg) was demonstrated in the study.
It is concluded that the opioid system of the mole-rat
plays no role in the regulation of thermal nociception. In the
naked mole-rat however, the opioid system seems to play an
important role in the regulation of aggressive and motor
behaviour. | en |
