Neonatal oxytocin treatment modulates oxytocin receptor, atrial natriuretic peptide, nitric oxide synthase and estrogen receptor mRNAs expression in rat heart

Abstract

Oxytocin (OT) has been implicated in reproductive functions, induction of maternal behavior as well as endocrine and neuroendocrine regulation of the cardiovascular system. Here we demonstrate that neonatal manipulation of OT can modulate the mRNAs expression for OT receptor (OTR), atrial natriuretic peptide (ANP), endothelial nitric oxide synthase (eNOS) and estrogen receptor alpha (ERα) in the heart. On the first day of postnatal life, female and male rats were randomly assigned to receive one of following treatments; (a) 50 µl i.p. injection of 7 µg OT, (b) 0.7 µg of OT antagonist (OTA), or (c) isotonic saline (SAL). Hearts were collected either on postnatal day 1 or day 21 (D1 or D21) and the mRNAs expression of OTR, ANP, inducible NOS (iNOS), eNOS, ERα and estrogen receptor beta (ERβ) were compared by age, treatment, and sex utilizing Real Time PCR. OT treatment significantly increased heart OTR, ANP and eNOS mRNAs expression on D1 in both males and females, ERα increased only in females. While there were significant changes in the relative expression of all types of mRNA between D1 and D21 there were no significant treatment effects observed in D21 animals. OTA treatment significantly decreased basal ANP and eNOS mRNAs expression on D1 in both sexes. The results indicate that during the early postnatal period OT can have an immediate effect on the expression OTR, ANP, eNOS, and ERα mRNAs and that these effects are mitigated by D21. Also with the exception of ERα mRNA, the effects are the same in both sexes.

Is Oxytocin a Maternal–Foetal Signalling Molecule at Birth? Implications for Development

“…Early‐life oxytocin also affected the reproductive potential of males in adulthood because they were less likely to transfer sperm to a female . These treatments, along with early‐life oxytocin antagonism affect the expression of oxytocin, the oxytocin receptor, the closely‐related neuropeptide vasopressin and its receptor, as well as oestrogen receptor α . Such results highlight the importance of the oxytocin signal in early life.…”

Effects of social isolation on mRNA expression for corticotrophin-releasing hormone receptors in prairie voles

“…cDNA synthesis and polymerase chain reaction (PCR) amplification for CRH, CRH-R1 and CRH-R2 mRNAs was performed using the ThermalCycler PCR as described previously (Pournajafi-Nazarloo et al, 2007b, 2003). Briefly, total RNA (3 μg) was combined with 25 pmol oligo-d(T) primer, 0.5 μl RNAse inhibitor, and brought to a total volume of 12 μl using DEPC water.…”

Is preconditioning by oxytocin administration mediated by iNOS and/or mitochondrial KATP channel activation in the in vivo anesthetized rabbit heart?

“…OXT is known to stimulate NO release during ischemia-reperfusion in rats (Dusunceli et al, 2008;Pournajafi-Nazarloo et al, 2007). Two recent reports suggest that the protective effects of OXT pretreatment on ischemia-reperfusion injury may be caused by this NO release (Dusunceli et al, 2008;Tugtepe et al, 2007).…”