Vascular Effects of Perinatal Hypoxia in the Early Postnatal Period in Rats

Abstract

The normal functioning of the vascular system in early ontogenesis can be altered by adverse effects affecting the organism of the fetus / newborn during pregnancy, during or after childbirth. However, at the moment there is not enough data on the “acute” (immediately after exposure) and “delayed” (after several days) effects of short-term (within several hours) perinatal normobaric hypoxia on the functioning of the peripheral vascular system of the systemic circulation in early ontogenesis in mammals. The aim of this work was to study the “acute” and “delayed” effects of a single normobaric hypoxia on the functioning of the arteries of the systemic circulation in early postnatal ontogenesis. The contractile responses of the saphenous artery of rats aged 10–14 days were studied in isometric myograph. Acute normobaric hypoxia (8% O2) was simulated for 2 hours in 10-day-old rat pups. The selected hypoxia regimen did not lead to changes in arterial contractile responses to the α1-adrenergic agonist methoxamine either immediately after exposure or several days later. Endothelium-dependent relaxation of arteries to acetylcholine also did not differ between groups. Hypoxia did not change the contribution of anticontractile pathways associated with nitric oxide and Kv7 channels, as well as the pro contractile role of Rho-kinase. Thus, according to the presented results, short-term normobaric hypoxia on the 10th day of life in rat pups does not lead to either “acute” or “delayed” changes in the regulation of the tone of the peripheral arteries of the systemic circulation in the early postnatal period.