Prenatal hypoxia in rats increased blood pressure and sympathetic drive of the adult offspring

Abstract

Decreased oxygenation during pregnancy and early periods of ontogeny can affect normal body development and result in diseases in adulthood. The aim of this study was to use the model of prenatal intermittent hypoxia (PIH) and evaluate the effects of short-term hypoxia at the end of gestation on blood pressure (BP) control in adulthood. Wistar rats were exposed daily to PIH for 4 h during gestational day 19 and 20. In adult male rats, heart rate (HR), systolic BP and pulse pressure (PP) were acquired by radiotelemetry during 1 week. On the basis of HR variability and BP variability, sympathovagal balance (LF/HF) and spontaneous baroreflex sensitivity (sBRS) were evaluated. Systolic BP and PP were significantly elevated in PIH rats in comparison with control rats during the light and dark phase of the day, while LF/HF increased only during the light phase of the day. In contrast, sBRS tended to decrease only during the dark phase in PIH rats. In all measured and calculated parameters, significant circadian rhythms were present and were not affected by PIH. In conclusion, our data suggest that short intermittent hypoxia at the end of gestation can increase BP and PP via significant changes in LF/HF, which occur especially during the passive phase of the day. Results suggest that minor changes in the autonomous nervous system activity induced by environmental conditions during the perinatal period may contribute to development of hypertension in adulthood.

Intermittent hypoxia in utero damages postnatal growth and cardiovascular function in rats

“…†P Ͻ 0.05 or † †P Ͻ 0.01, compared with males with the same treatment. vascular and autonomic nervous system, including hypertension (17,59), elevated muscle sympathetic nerve activity (53), altered baroreflex and ventilatory responses to acute hypoxia (11,59), altered vascular reactions to vasoconstrictive and vasodilator agents (5,11,60,65), and in vitro LV dysfunction (31). Some of these changes are sustained to adulthood (5,11,31,53,60,65).…”

Hypertension Programmed in Adult Hens by Isolated Effects of Developmental Hypoxia In Ovo

“…Several mammalian studies have also demonstrated that development under hypoxic conditions can program hypertension in the adult offspring. 16 – 18 The present study highlights that a least a component of the hypertension programmed developmentally in mammals is due to the direct effects of hypoxia on the developing embryo, independent of any maternal or placental effects.…”

“…Studies using mammalian animal models, mostly in rodents and sheep, have shown that hypoxic pregnancy can program hypertension in the adult offspring via alterations in NO biology and sympathetic reactivity in the cardiovascular system. 16 – 18 Such studies, together with ours, have used several techniques to induce chronic fetal hypoxia, including hypoxic chambers, 17 , 19 – 21 uterine artery blood flow restriction, 16 , 22 placental embolization, 23 , 24 umbilical artery ligation, 25 carunclectomy, 26 and exposure to high altitude. 27 – 29 Methods such as uterine artery restriction, placental embolization, or umbilical artery ligation will also reduce nutrient transfer to the fetus, and pregnant mammals placed in hypoxic chambers sometimes show reduced food intake, 30 – 32 although this is not always the case.…”

Pineal gland calcification under hypoxic conditions

“…More frequent sampling over the whole 24 h cycle is needed to reveal possible smaller changes in amplitude and/or acrophase of the melatonin rhythmicity. In our previous study prenatal hypoxia increased blood pressure in mature offspring, especially during the darktime, but did not affect circadian rhythms in cardiovascular parameters (Svitok et al 2016).…”