硝普钠对豚鼠气管的舒张作用：与环磷酸鸟苷和一氧化氮无关。

Relaxation of guinea-pig trachea by sodium nitroprusside: cyclic GMP and nitric oxide not involved.

Sadeghi-Hashjin G, Folkerts G, Henricks P A, van de Loo P G, Dik I E, Nijkamp F P

Department of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, The Netherlands.

Br J Pharmacol. 1996 Jun;118(3):466-70. doi: 10.1111/j.1476-5381.1996.tb15426.x.

Abstract

Sodium nitroprusside (SNP) completely relaxed the guinea-pig isolated, perfused trachea in a concentration-dependent manner. Although SNP was less potent by about 2 orders of magnitude, its maximal effect was 25% higher compared to isoprenaline. 2. SNP (3.2 microM) increased cyclic GMP levels by 300% and relaxed guinea-pig isolated, perfused trachea by 54%. The SNP-induced relaxations of the preparations were not affected by the guanylate cyclase inhibitor, methylene blue. Moreover, zaprinast, a cyclic GMP-specific phosphodiesterase inhibitor which was supposed to enhance SNP-induced relaxations, decreased the maximal relaxation by 22% (P < 0.001). 3. In contrast, 8Br-cyclic GMP (10 microM) increased the cyclic GMP levels by 1100% without inducing a marked relaxation. 4. SNP (10 microM) and S-nitroso-N-acetylpenicillamine (SNAP; a direct donor of nitric oxide; 10 microM), relaxed the tissues by 75% and 25%, respectively, without any nitric oxide (NO) release by SNP (< 1 pmol 100 microliters-1), but a substantial NO release by SNAP (560 pmol 100 microliters-1). 5. It is concluded that the SNP-induced tracheal relaxations are probably not mediated by cyclic GMP and NO.

摘要

硝普钠（SNP）能使豚鼠离体灌流气管以浓度依赖的方式完全舒张。尽管SNP的效力比异丙肾上腺素弱约2个数量级，但其最大效应比异丙肾上腺素高25%。2. SNP（3.2微摩尔）使环鸟苷酸（cGMP）水平升高300%，并使豚鼠离体灌流气管舒张54%。SNP诱导的该制剂舒张不受鸟苷酸环化酶抑制剂亚甲蓝的影响。此外，扎普司特是一种cGMP特异性磷酸二酯酶抑制剂，本应增强SNP诱导的舒张作用，却使最大舒张作用降低了22%（P<0.001）。3. 相比之下，8-溴环鸟苷酸（10微摩尔）使cGMP水平升高1100%，但未引起明显舒张。4. SNP（10微摩尔）和S-亚硝基-N-乙酰青霉胺（SNAP；一种一氧化氮直接供体；10微摩尔）分别使组织舒张75%和25%，SNP未释放任何一氧化氮（NO）（<1皮摩尔/100微升-1），但SNAP释放了大量NO（560皮摩尔/100微升-1）。5. 得出的结论是，SNP诱导的气管舒张可能不是由cGMP和NO介导的。