Bonavera J J, Sahu A, Kalra P S, Kalra S P
Department of Neuroscience, University of Florida College of Medicine, Gainesville 32610.
Brain Res. 1994 Oct 10;660(1):175-9. doi: 10.1016/0006-8993(94)90854-0.
Studies were undertaken to determine whether nitric oxide (NO) is involved in induction of the prolactin surge on proestrus and in that induced by ovarian steroids in ovariectomized (ovx) rats, by using inhibitors of NO synthase, the enzyme that generates NO. Two week-ovariectomized rats were treated either with estradiol benzoate (EB, 30 micrograms/rat, s.c.) alone, or with EB and 2 days later with progesterone (P, 2 mg/rat, s.c.) to evoke a prolactin surge in the afternoon. Injections of the NO synthase inhibitor Nw-nitro-L-arginine methyl ester (40 mg/kg, s.c.) at 10.000, 12.00, and 14.00 h completely suppressed the steroid-induced prolactin surge in the afternoon. Similarly, another NO synthase inhibitor, Nw-nitro-L-arginine (100 mg/kg, s.c.), injected at 1000, 1200, and 1400 h on proestrus suppressed prolactin and luteinizing hormone (LH) surges, but failed to alter the daily increase of corticosterone. These studies confirm our earlier report and show that NO is involved in the complex processes that initiate the afternoon prolactin and LH surges of proestrus.
本研究旨在通过使用一氧化氮合酶（生成一氧化氮的酶）抑制剂，确定一氧化氮（NO）是否参与动情前期催乳素激增的诱导过程，以及是否参与卵巢切除（ovx）大鼠中由卵巢类固醇诱导的催乳素激增过程。对两周卵巢切除的大鼠，单独给予苯甲酸雌二醇（EB，30微克/只，皮下注射），或先给予EB，2天后再给予孕酮（P，2毫克/只，皮下注射），以在下午引发催乳素激增。在10:00、12:00和14:00时皮下注射一氧化氮合酶抑制剂Nω-硝基-L-精氨酸甲酯（40毫克/千克），完全抑制了下午类固醇诱导的催乳素激增。同样，在动情前期的10:00、12:00和14:00时皮下注射另一种一氧化氮合酶抑制剂Nω-硝基-L-精氨酸（100毫克/千克），抑制了催乳素和促黄体生成素（LH）激增，但未能改变皮质酮的每日增加量。这些研究证实了我们早期的报告，并表明NO参与了引发动情前期下午催乳素和LH激增的复杂过程。
