Pinto C R F, Paccamonti D L, Eilts B E, Venugopal C S, Short C R, Gentry L R, Thompson D L, Godke R A
Equine Health Studies Program, Department of Comparative Biomedical Sciences, Louisiana State University and Agricultural Center, Baton Rouge, LA 70803, USA.
Theriogenology. 2003 Sep 15;60(5):819-27. doi: 10.1016/s0093-691x(03)00096-7.
In the present study, follicular fluids of estrous mares treated with saline solution (Control) or nitric oxide synthase (NOS) inhibitors were analyzed for nitric oxide (NO), estradiol-17beta (E2) and progesterone (P4) concentrations before and 36h after administration of human chorionic gonadotropin (hCG). Follicular fluids obtained before (0h) hCG administration from control mares had lower concentrations of NO than those obtained 36h after administration of hCG (58.3+/-17.8 micromol versus 340.4+/-57.7 micromol; P<0.05). A similar pattern was also noted for intrafollicular P4 in control mares, which had lower concentrations of intrafollicular P4 before hCG than 36h post-hCG administration (P<0.05). As expected, E2 concentrations of control follicles sampled before hCG administration were higher than those sampled 36h post-hCG administration (P<0.05). However, the E2 concentrations in follicles of mares treated with the NOS inhibitors N(omega)-nitro-L-arginine methyl ester (L-NAME) or aminoguanidine (AG) did not decrease after hCG administration, unlike those in control mares (P>0.10). In addition, mares treated with NOS inhibitors had lower intrafollicular concentrations of NO and P4 than control mares, both before and after hCG administration (P<0.05). Increased intrafollicular concentrations of NO in control, hCG-stimulated mares provide evidence for the presence of an NO-generating system in the equine preovulatory follicle that is likely upregulated following administration of hCG.
在本研究中，对用生理盐水溶液（对照）或一氧化氮合酶（NOS）抑制剂处理的发情母马的卵泡液，在注射人绒毛膜促性腺激素（hCG）之前和之后36小时分析其一氧化氮（NO）、雌二醇-17β（E2）和孕酮（P4）浓度。从对照母马在hCG注射前（0小时）获得的卵泡液中NO浓度低于在hCG注射后36小时获得的卵泡液（58.3±17.8微摩尔对340.4±57.7微摩尔；P<0.05）。对照母马卵泡内P4也有类似模式，hCG注射前卵泡内P4浓度低于hCG注射后36小时（P<0.05）。正如预期的那样，hCG注射前采集的对照卵泡的E2浓度高于hCG注射后36小时采集的卵泡（P<0.05）。然而，与对照母马不同，用NOS抑制剂N（ω）-硝基-L-精氨酸甲酯（L-NAME）或氨基胍（AG）处理的母马卵泡中的E2浓度在hCG注射后没有降低（P>0.10）。此外，在hCG注射前后，用NOS抑制剂处理的母马卵泡内NO和P4浓度均低于对照母马（P<0.05）。在对照的、hCG刺激的母马中卵泡内NO浓度增加，这为马排卵前卵泡中存在一个NO生成系统提供了证据，该系统在hCG注射后可能被上调。
