Hoffmann O, Plesan A, Wiesenfeld-Hallin Z
Department of Medical Laboratory Sciences and Technology, Division of Clinical Neurophysiology, Huddinge University Hospital, S-141 86 Huddinge, Sweden.
Brain Res. 1998 Sep 28;806(2):232-7. doi: 10.1016/s0006-8993(98)00768-9.
Significant genetic differences in the endogenous opioid system and in response to a variety of noxious stimuli are present in rodents. We now compared the response to noxious heat with the hot plate test, morphine sensitivity and the development of tolerance and dependence to morphine in spontaneously hypertensive (SHR), Wistar-Kyoto (WK) and Sprague-Dawley (SD) rats. Significant differences were observed in basal nociception among the three strains, where SHRs were hypoalgesic compared to WK and SD. The antinociceptive effect of morphine varied among strains (SD>SHR>WK) as did the rate of tolerance development (10 mg/kg morphine 2/day for 4 days) where WK>SD=SHR. SHR rats developed hyperalgesia following morphine administration during the course of tolerance development. Furthermore, although naloxone (2 mg/kg) precipitated withdrawal symptoms in all tolerant rats, the panorama of symptoms varied among the three strains. Thus, there are significant genetic differences in a variety of effect of opiates.
啮齿动物体内的内源性阿片系统以及对多种有害刺激的反应存在显著的基因差异。我们现在比较了自发性高血压大鼠（SHR）、Wistar-Kyoto大鼠（WK）和Sprague-Dawley大鼠（SD）对热板试验中有害热刺激的反应、吗啡敏感性以及对吗啡耐受性和依赖性的发展情况。在这三个品系的基础伤害感受方面观察到显著差异，与WK和SD相比，SHR的痛觉过敏。吗啡的镇痛作用在不同品系间有所不同（SD>SHR>WK），耐受性发展速率也是如此（每天2次，每次10mg/kg吗啡，持续4天），其中WK>SD=SHR。在耐受性发展过程中，SHR大鼠在给予吗啡后会出现痛觉过敏。此外，虽然纳洛酮（2mg/kg）在所有耐受性大鼠中都会引发戒断症状，但三个品系的症状表现各异。因此，阿片类药物的多种作用存在显著的基因差异。
