The role of nitric oxide in dilating the fetal ductus arteriosus in rats

68Citations
Citations of this article
16Readers
Mendeley users who have this article in their library.

This article is free to access.

Abstract

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(ω)-nitro-L-arginine methyl ester (LNAME), 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 prostaglandin 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 constriction, 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.

Cite

CITATION STYLE

APA

Momma, K., & Toyono, M. (1999). The role of nitric oxide in dilating the fetal ductus arteriosus in rats. Pediatric Research, 46(3), 311–315. https://doi.org/10.1203/00006450-199909000-00010

Register to see more suggestions

Mendeley helps you to discover research relevant for your work.

Already have an account?

Save time finding and organizing research with Mendeley

Sign up for free