Dr. Gilbert will present the research on the physiology of cardiovascular disease: Gender disparities conference, October 12 to 14 at the University of Mississippi in Jackson. The conference is sponsored by the American Physiological Society with additional support from the American Heart Association. His presentation is titled “Training exercise before and during pregnancy improves endothermic function and stimulates overprotective and antioxidant pathways in pregnant rats.”
VEGF
In the study, rats were divided into two groups, the exercise group and the control group, and impregnated later. The exercise group ran voluntarily on a wheel of activity for six weeks before and during pregnancy, with running times and distances up weekly. The control group did not exercise. The team analyzed tissue samples from both groups at the end of pregnancy.
The researchers found that rats in the exercise group had higher levels of a circulating protein called vascular endothermic growth factor (VEGF) than the control group. VEGF and pregnancy-specific version of a protein called placental growth factor (PlGF) are important because not only stimulate the development of new blood vessels, also to maintain the normal function of the vessels which in turn promotes good cardiovascular health.
According to Dr. Gilbert, the pursuit of VEGF increased in the exercise group has important implications for understanding, and perhaps the prevention of preeclampsia. He noted that clinical and experimental studies have shown that high levels of a protein called sFlt-1 can be attached to the mother’s levels of circulating VEGF and PlGF and may lead to preeclampsia.
The researchers also found that when VEGF increased, increased endothermic function. The endothermic is a thin layer of cells lining the inside of blood vessels. Turbulence is reduced blood flow, allowing more blood is pumped with each heartbeat, giving the strain on the heart.
Heat shock proteins
The team also found that rats in the exercise group had increased amounts of heat shock proteins (HSP) compared with those who did not exercise. A HSP, including HSP 90, are believed to play a vital role in maintaining the heart’s blood vessels. It works in sync with the VEGF and nitric oxide to dilate blood vessels so blood flows more freely, reducing blood pressure. Increased expression of HSPs, as a result of exercise can provide a preconditioning effect that can help protect against cell damage in the placenta during pregnancy complicated by high blood pressure.
“There have been many studies on exercise and pregnancy, but not at the molecular level,” said Gilbert. “We hope to know whether the stimulation of these proteins with the year before pregnancy or during early pregnancy can reduce a woman’s risk of preeclampsia.”
