Research on the age-related changes in the nitric oxide pathway in the arteries of rats and the intervention effect of dehydroepiandrosterone.

BACKGROUND

Aging, especially the aging of blood vessels, is a dangerous independent factor in the occurrence and development of cardiovascular and cerebrovascular diseases. However, the cellular and molecular pathologic mechanisms underlying the aging of blood vessels remain unclear.

PURPOSE

To observe changes in the nitric oxide (NO) pathway and the interventional effects of dehydroepiandrosterone (DHEA) in the artery during the aging process.

METHODS

Male Wistar rats were divided into 3 experimental groups of 6 rats each: group 1, adult control 12-month-old rats fed conventional fodder; group 2, 18-month-old rats fed conventional fodder, and group 3, 18-month-old rats that received 1 mg/kg/ DHEA in their fundamental fodder when they were 12 months old. The thoracic aorta was chosen. Endothelial NO synthase protein was measured using the Western blot method, the amount of NO using the Griess method, the amount of cGMP using radioimmunoassay, and the activity of superoxide dismutase (SOD) and the amount of malonyldialdehyde (MDA) using colorimetry.

RESULT

Compared with the adult group, in the aortas of 18-month-old rats the protein expression of endothelial NO synthase (eNOS) is lower; the activity of SOD is lower but the amount of MDA is higher; the amounts of NO and cGMP are lower, but after DHEA intervention these changes are apparently ameliorated in the aged group.

CONCLUSION

During the aging process in rat arteries, the expression of eNOS is lowered, the function of oxidation resistance is weakened, and the response of the vascular smooth muscle to NO is apparently decreased. DHEA is able to ameliorate the function of NO-related signal pathways and delay the aging process of the blood vessels.