Rao V S, Chaves M C, Ribeiro R A
Departamento de Fisiologia e Farmacologia, Universidade Federal do Ceará, Fortaleza, Ce, Brazil.
J Reprod Fertil. 1995 Nov;105(2):303-6. doi: 10.1530/jrf.0.1050303.
The role of nitric oxide in the uterotrophic action of oestradiol after 6 h or 72 h was studied in immature (19-21 days old) female Wistar rats by use of L-arginine, the amino acid from which nitric oxide is synthesized, and N omega-nitro-L-arginine methyl ester (L-NAME), an inhibitor of nitric oxide synthase. Oestradiol at single s.c. doses of 2.5, 5.0 and 10.0 micrograms per rat induced dose-dependent uterine oedema in 6 h. L-NAME (10 and 20 mg kg-1, i.p.) administered 30 min before oestradiol (10 micrograms per rat) injection suppressed the formation of uterine oedema in a dose-related manner. This action of L-NAME on oestradiol-induced uterine oedema was effectively blocked by pretreatment of rats with L-arginine (600 mg kg-1, s.c.), a precursor of nitric oxide, but not by L-lysine, an amino acid not involved in the generation of nitric oxide. In addition, L-NAME at similar doses significantly prevented oestradiol-induced (3 micrograms per rat, s.c. on three successive days) increases in uterine growth after 72 h; however, this effect was mitigated by L-arginine (600 mg kg-1). These results suggest the involvement of an L-arginine-nitric oxide system in the oestradiol-induced uterotrophic effect in immature rats.
通过使用L-精氨酸（一氧化氮合成所源自的氨基酸）和一氧化氮合酶抑制剂Nω-硝基-L-精氨酸甲酯（L-NAME），研究了一氧化氮在未成熟（19 - 21日龄）雌性Wistar大鼠中，在6小时或72小时后对雌二醇子宫营养作用的影响。每只大鼠单次皮下注射2.5、5.0和10.0微克雌二醇，在6小时内可诱导剂量依赖性的子宫水肿。在注射雌二醇（每只大鼠10微克）前30分钟腹腔注射L-NAME（10和20毫克/千克），以剂量相关的方式抑制子宫水肿的形成。L-NAME对雌二醇诱导的子宫水肿的这种作用，可被用一氧化氮前体L-精氨酸（600毫克/千克，皮下注射）预处理大鼠有效阻断，但不能被不参与一氧化氮生成的氨基酸L-赖氨酸阻断。此外，相似剂量的L-NAME可显著阻止雌二醇（每只大鼠3微克，连续三天皮下注射）在72小时后诱导的子宫生长增加；然而，这种作用可被L-精氨酸（600毫克/千克）减轻。这些结果表明，L-精氨酸 - 一氧化氮系统参与了未成熟大鼠中雌二醇诱导的子宫营养作用。
