Nitric oxide prolongs parturition and inhibits maternal behavior in rats.
We examined the effect of nitric oxide (NO) on the process of parturition in rats. Subcutaneous injection of the NO donor sodium nitroprusside (SNP) in late pregnancy prolonged the total parturition time. The effect of N omega-nitro-L-arginine was not significantly different from that of saline. Intracerebroventricular injection of SNP in parturient rats delayed the progress of parturition. Both modes of SNP treatment also inhibited expression of maternal behavior. Central injection of oxytocin (OXT) with SNP failed to reduce parturition time significantly, but intrapartum, not postpartum, maternal behaviour was restored. These observations suggest that NO interferes with the release of OXT within the brain, hence affecting the initiation of maternal behaviour, and may also impair oxytocin secretion from the neurohypophysis.
Department of Physiology, Kochi Medical School, Japan.
C O
CO
Okere
T
T
Higuchi
H
H
Kaba
J A
JA
Russell
F
F
Okutani
S
S
Takahashi
T
T
Murata
D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D005260:Female; D007743:Labor, Obstetric / Q000187:drug effects*; D008425:Maternal Behavior / Q000187:drug effects*; D009569:Nitric Oxide / Q000494:pharmacology*; D011247:Pregnancy; D051381:Rats; D017207:Rats, Sprague-Dawley
D009569:Nitric Oxide