Leventhal L, Kirkham T C, Cole J L, Bodnar R J
Department of Psychology, Queens College, City University of New York, Flushing 11367, USA.
Brain Res. 1995 Jul 10;685(1-2):205-10. doi: 10.1016/0006-8993(95)00385-4.
Intake of a palatable sucrose solution in real-fed rats is mediated in part by central mu and kappa opioid receptors. Since general opioid antagonists still inhibit sucrose intake in sham-fed rats, the present study examined whether centrally administered mu (beta-funaltrexamine: 5, 20 micrograms), mu1 (naloxonazine: 50 micrograms), kappa (nor-binaltorphamine: 1, 5, 20 micrograms), delta (naltrindole: 20 micrograms) or delta 1 (DALCE: 40 micrograms) opioid subtype antagonists altered sucrose intake in sham-fed rats in a similar manner to systemic naltrexone (0.01-1 mg/kg) and whether such effects were equivalent to altering the sucrose concentration. Sucrose (20%) intake in sham-fed rats was significantly and dose-dependently reduced by naltrexone (59%), beta-funaltrexamine (44%) and nor-binaltorphamine (62%), but not by naloxonazine, naltrindole or DALCE. The reductions in sham sucrose (20%) intake by general, mu and kappa antagonism were similar in pattern and magnitude to diluting sucrose concentration from 20% to 10% in untreated sham-fed rats. Since both real-fed and sham-fed rats share similar patterns of specificity of opioid effects, magnitudes and potencies of inhibition, it suggests that central mu and kappa antagonism acts on orosensory mechanisms supporting sucrose intake.
实喂大鼠对可口蔗糖溶液的摄取部分由中枢μ和κ阿片受体介导。由于一般阿片拮抗剂仍能抑制假喂大鼠的蔗糖摄取，本研究检测了中枢给予μ（β-氟纳曲胺：5、20微克）、μ1（纳洛嗪：50微克）、κ（去甲二氢吗啡酮：1、5、20微克）、δ（纳曲吲哚：20微克）或δ1（DALCE：40微克）阿片亚型拮抗剂，是否会以与全身给予纳曲酮（0.01 - 1毫克/千克）相似的方式改变假喂大鼠的蔗糖摄取，以及这种效应是否等同于改变蔗糖浓度。纳曲酮（59%）、β-氟纳曲胺（44%）和去甲二氢吗啡酮（62%）可显著且剂量依赖性地降低假喂大鼠对20%蔗糖的摄取，但纳洛嗪、纳曲吲哚或DALCE则无此作用。一般、μ和κ拮抗剂对假喂大鼠20%蔗糖摄取的降低，在模式和幅度上与未处理的假喂大鼠将蔗糖浓度从20%稀释至10%相似。由于实喂和假喂大鼠在阿片效应的特异性模式、抑制幅度和效力方面具有相似性，这表明中枢μ和κ拮抗作用作用于支持蔗糖摄取的口感觉机制。
