Impact of in vitro embryo culture and transfer on blood pressure regulation in the adolescent lamb.

Nutrition during the periconceptional period influences postnatal cardiovascular health. We determined whether in vitro embryo culture and transfer, which are manipulations of the nutritional environment during the periconceptional period, dysregulate postnatal blood pressure and blood pressure regulatory mechanisms. Embryos were either transferred to an intermediate recipient ewe (ET) or cultured in vitro in the absence (IVC) or presence of human serum (IVCHS) and a methyl donor (IVCHS+M) for 6 days. Basal blood pressure was recorded at 19-20 weeks after birth. Mean arterial pressure (MAP) and heart rate (HR) were measured before and after varying doses of phenylephrine (PE). mRNA expression of signaling molecules involved in blood pressure regulation was measured in the renal artery. Basal MAP did not differ between groups. Baroreflex sensitivity, set point, and upper plateau were also maintained in all groups after PE stimulation. Adrenergic receptors alpha-1A (αAR1A), alpha-1B (αAR1B), and angiotensin II receptor type 1 (AT1R) mRNA expression were not different from controls in the renal artery. These results suggest there is no programmed effect of ET or IVC on basal blood pressure or the baroreflex control mechanisms in adolescence, but future studies are required to determine the impact of ET and IVC on these mechanisms later in the life course when developmental programming effects may be unmasked by age.

The periconceptional environment and cardiovascular disease: does in vitro embryo culture and transfer influence cardiovascular development and health?

Assisted Reproductive Technologies (ARTs) have revolutionised reproductive medicine; however, reports assessing the effects of ARTs have raised concerns about the immediate and long-term health outcomes of the children conceived through ARTs. ARTs include manipulations during the periconceptional period, which coincides with an environmentally sensitive period of gamete/embryo development and as such may alter cardiovascular development and health of the offspring in postnatal life. In order to identify the association between ARTs and cardiovascular health outcomes, it is important to understand the events that occur during the periconceptional period and how they are affected by procedures involved in ARTs. This review will highlight the emerging evidence implicating adverse cardiovascular outcomes before and after birth in offspring conceived through ARTs in both human and animal studies. In addition, it will identify the potential underlying causes and molecular mechanisms responsible for the congenital and adult cardiovascular dysfunctions in offspring whom were conceived through ARTs.

Early origins of heart disease: low birth weight and the role of the insulin-like growth factor system in cardiac hypertrophy.

Epidemiological studies indicate that poor growth before birth is associated with left ventricular hypertrophy and an increased risk of death from heart disease later in life. In fetal life, the insulin-like growth factor (IGF) system has been implicated in physiological growth of the heart, whereas in postnatal life IGFs can be involved in both physiological and pathological cardiac hypertrophy. A reduction in substrate supply in fetal life, resulting in chronic hypoxaemia and intrauterine growth restriction, results in increased cardiac IGF-1R, IGF-2 and IGF-2R gene expression; and there is also evidence for a role of the IGF-2 receptor in the ensuing cardiac hypertrophy. The persistent high level of cardiac IGF-2R gene expression from fetal to postnatal life may be due to epigenetic changes in key cardiac hypertrophy regulatory pathways.