Mascolo N, Izzo A A, Gaginella T S, Capasso F
Department of Experimental Pharmacology, School of Pharmacy, Naples, Italy.
Naunyn Schmiedebergs Arch Pharmacol. 1996 May;353(6):680-4. doi: 10.1007/BF00167187.
The modulation of platelet activating factor (PAF) formation in duodenal tissue by nitric oxide (NO) released in response to castor oil was studied in rats pretreated with NG-nitro-L-arginine methyl ester (L-NAME, 6.25-25 mg/kg, i.p.), an inhibitor of NO synthase, NG-nitro-D-arginine methyl ester (D-NAME, 25 mg/kg, i.p.), the inactive enantiomer of L-NAME or isosorbide-5-mononitrate (IMN, 30-90 mg/kg, p.o.), a NO donating compound. Castor oil (2 ml/rat orally) increased PAF production in the rat duodenum 3 h after challenge. L-NAME, but not D-NAME, enhanced the amount of PAF formed by duodenal tissue, while IMN (30-90 mg/kg) counteracted the effects of L-NAME (12.5 mg/kg) and also reduced PAF release in the tissue of rats treated with castor oil. L-NAME 12.5 mg/kg, but not D-NAME, enhanced both macroscopic damage and acid phosphatase release induced by castor oil. These effects were reduced by a PAF antagonist BN 52021 (3-t-Butyl-hexahydro-4, 7b, 11-trihydroxy-8-methyl-9H-1, 7a-epoxymethano-1H, 6aH-cyclopenta [c] furo [2, 3b] furo [3'2':3,4] cyclopenta [1.2-d]furan-5,9,12(4H)trione) 10 and 20 mg/kg i.p. Such findings suggest that endogenous nitric oxide could reduce PAF biosynthesis in castor oil-treated rats.
在经NG-硝基-L-精氨酸甲酯（L-NAME，6.25 - 25毫克/千克，腹腔注射）预处理的大鼠中，研究了一氧化氮（NO）对蓖麻油刺激后十二指肠组织中血小板活化因子（PAF）生成的调节作用。L-NAME是一种一氧化氮合酶抑制剂，NG-硝基-D-精氨酸甲酯（D-NAME，25毫克/千克，腹腔注射）是L-NAME的无活性对映体，而异山梨醇-5-单硝酸盐（IMN，30 - 90毫克/千克，口服）是一种供NO的化合物。蓖麻油（2毫升/只，口服）刺激3小时后可增加大鼠十二指肠中PAF的产生。L-NAME可增强十二指肠组织中PAF的生成量，而D-NAME则无此作用，IMN（30 - 90毫克/千克）可抵消L-NAME（12.5毫克/千克）的作用，并降低蓖麻油处理大鼠组织中PAF的释放。L-NAME 12.5毫克/千克可增强蓖麻油诱导的宏观损伤和酸性磷酸酶释放，而D-NAME则无此作用。PAF拮抗剂BN 52021（3-叔丁基-六氢-4,7b,11-三羟基-8-甲基-9H-1,7a-环氧亚甲基-1H,6aH-环戊[c]呋喃[2,3b]呋喃[3'2':3,4]环戊[1.2-d]呋喃-5,9,12(4H)三酮）10和20毫克/千克腹腔注射可减轻这些作用。这些发现表明，内源性一氧化氮可减少蓖麻油处理大鼠中PAF的生物合成。
