The role of nitric oxide in dilating the fetal ductus arteriosus in rats
The role of nitric oxide in dilating the fetal ductus arteriosus in rats
复制标题
DOI：
10.1203/00006450-199909000-00010
复制
发表时间：
1999-09-01
影响因子：
3.6
通讯作者：
Toyono, M
中科院分区：
文献类型：
--
作者：
Momma, K;Toyono, M
Prostaglandin E is a major dilator of the fetal ductus arteriosus (DA), but the role of nitric oxide in fetal ductal dilation has not been established. We studied the effects of a potent nitric oxide synthase inhibitor, N-omega-nitro-L-arginine methyl ester (L-NAME), on the fetal DA in rats. L-NAME was injected into the dorsum of pregnant rats, and fetal DA was studied 4 h later with a rapid whole body freezing method. The inner diameters of the DA and the main pulmonary artery were measured on a freezing microtome. The inner diameter ratio of DA to main pulmonary artery (DA-PA) was 1.02 +/- 0.03 (mean +/- SEM; number of fetuses [n]? 21) in normal near-term fetuses. The effect of pros taglandin synthesis inhibition was studied after orogastric administration of indomethacin to pregnant rats. In near-term rats on the 21st day of gestation (term, 21.5 d), a large dose of L-NAME (100 mg/kg) caused only mild ductal constriction, with DA/PA reduced to 0.83 +/- 0.05 (n = 20). Indomethacin (1 mg/kg) caused moderate ductal constriction, and DA/PA was decreased to 0.65 +/- 0.05 (n = 21). Combined administration of L-NAME (10 mg/kg;) and indomethacin (1 mg/kg) caused severe ductal con-striction, with DA/PA of 0.26 +/- 0.03 (n = 16). In preterm rats on the 19th day of gestation, a moderate dose of L-NAME (10 mg/kg) caused severe ductal constriction, with a DA/PA of 0.32 +/- 0.05 (n = 24). Indomethacin(1 mg/kg) alone caused only mild ductal constriction, with DA/PA 0.86 +/- 0.02 (n = 16). In conclusion, prostaglandin has a major role and nitric oxide has a minor role in dilating the DA in the near-term fetal rat. In contrast, nitric oxide has a major role and prostaglandin has a minor role in dilating the DA in preterm fetal rats.
