Fogel R, Kaplan R B
Am J Physiol. 1984 Apr;246(4 Pt 1):G386-92. doi: 10.1152/ajpgi.1984.246.4.G386.
Intraluminal administration of naloxone (10(-4) M), a mu-opiate receptor antagonist, or diprenorphine (10(-6) M), an opiate receptor antagonist with high affinity for both delta- and mu-receptors, decreased basal in vivo water and electrolyte absorption in the jejunum and ileum but not the colon of the rat. Diprenorphine (10(-5) M) decreased basal colonic water transport. These changes were not due to a reduction in mucosal Na-K-ATPase activity. Intravenous atropine prevented as well as abolished the changes in water transport due to naloxone. The diprenorphine-induced changes were not altered by atropine. Naloxone and diprenorphine acted by different receptors. Pretreatment with naloxone (10(-4) M) prevented the increase in water transport due to morphine, a mu-agonist, whereas a higher concentration of naloxone (10(-3) M) was required to inhibit the increase due to D-Ala-methionine-enkephalinamide, a delta-receptor agonist. In contrast, diprenorphine (10(-6) M) abolished the absorption caused by morphine and D-Ala-methionine-enkephalinamide. Diprenorphine (3 X 10(-7) M) partially prevented the morphine-induced increase in water absorption.(ABSTRACT TRUNCATED AT 250 WORDS)
在大鼠体内，向肠腔内注射μ阿片受体拮抗剂纳洛酮（10⁻⁴ M）或对δ和μ受体均具有高亲和力的阿片受体拮抗剂二丙诺啡（10⁻⁶ M），可降低空肠和回肠而非结肠的基础水和电解质吸收。二丙诺啡（10⁻⁵ M）可降低结肠基础水转运。这些变化并非由于黏膜钠钾ATP酶活性降低所致。静脉注射阿托品可预防并消除纳洛酮引起的水转运变化。阿托品并未改变二丙诺啡引起的变化。纳洛酮和二丙诺啡通过不同受体发挥作用。用纳洛酮（10⁻⁴ M）预处理可预防μ激动剂吗啡引起的水转运增加，而抑制δ受体激动剂D - 丙氨酸 - 甲硫氨酸 - 脑啡肽酰胺引起的增加则需要更高浓度的纳洛酮（10⁻³ M）。相比之下，二丙诺啡（10⁻⁶ M）可消除吗啡和D - 丙氨酸 - 甲硫氨酸 - 脑啡肽酰胺引起的吸收。二丙诺啡（3×10⁻⁷ M）可部分预防吗啡引起的水吸收增加。（摘要截短于250字）
