Agarwal R K, Court M, Chandna V K, Mohan A, Engelking L R, Kumar A M
Department of Anatomy and Cellular Biology, Tufts University School of Veterinary Medicine, N. Grafton, MA 01536.
Brain Res Bull. 1994;35(3):273-7. doi: 10.1016/0361-9230(94)90134-1.
Rats were exposed to either oxygen (controls), 1.5% halothane in oxygen, or methoxyflurane (0.5%) in oxygen over a period of 2 h, then sacrificed at the end of exposure (2-h group), 4 h after removal from environmental chamber (4-h group), or at 24 h following anesthetic exposure (24-h group). Pituitary (excluding the neural lobe, Pit), brain, and spinal cord areas were isolated and processed with Met-enkephalin tissue concentrations determined. In halothane-exposed animals, Met-enkephalin concentrations in pit and across CNS areas studied were significantly lower at 2 h following anesthetic exposure than in control animals. Concentrations of Met-enkephalin in many areas of CNS and Pit of 4-h group approached control levels. Concentrations of Met-enkephalin in all areas studied except spinal cord returned to basal levels by 24 h following halothane exposure. Exposure to methoxyflurane resulted in less dramatic changes in Met-enkephalin concentrations across CNS regions examined. Exposure to methoxyflurane resulted in significant decreases in Met-enkephalin levels in olfactory bulb, thalamus, and hippocampus only. Met-Enkephalin levels did not change significantly in other areas of the central nervous system following methoxyflurane exposure. These results indicate that halothane and methoxyflurane may have differential effects on the endogenous opioid system.
将大鼠暴露于氧气（对照组）、氧气中1.5%的氟烷或氧气中0.5%的甲氧氟烷环境中2小时，然后在暴露结束时（2小时组）、从环境舱移出后4小时（4小时组）或麻醉暴露后24小时（24小时组）处死。分离垂体（不包括神经叶，Pit）、脑和脊髓区域并进行处理，测定甲硫氨酸脑啡肽组织浓度。在氟烷暴露的动物中，麻醉暴露2小时后，Pit以及所研究的中枢神经系统区域中的甲硫氨酸脑啡肽浓度显著低于对照动物。4小时组中枢神经系统和Pit许多区域的甲硫氨酸脑啡肽浓度接近对照水平。氟烷暴露24小时后，除脊髓外，所有研究区域的甲硫氨酸脑啡肽浓度均恢复到基础水平。暴露于甲氧氟烷导致所检查的中枢神经系统区域中甲硫氨酸脑啡肽浓度变化较小。暴露于甲氧氟烷仅导致嗅球、丘脑和海马体中甲硫氨酸脑啡肽水平显著降低。甲氧氟烷暴露后，中枢神经系统其他区域的甲硫氨酸脑啡肽水平无显著变化。这些结果表明，氟烷和甲氧氟烷对内源性阿片系统可能有不同的影响。
