Role of nitric oxide in the pathophysiology of lead-induced cardiovascular diseases in rats

Abstract EN

BACKGROUND AND AIM: Exposure to lead is an environmental and occupational setting continues to be a serious public health problem.

Lead affects many organs and systems in human, where the cardiovascular system is one of the important targets.

The mechanism of lead induced hypertension and cardiac diseases remain unclear.

This study is designed to investigate the role of nitric oxide (NO) in the pathophysiologic mechanisms of lead- induced cardiovascular diseases in rats.

METHODS: 40 rats were used and divided into 4 equal groups.

The first group was left without treatment served as a control group.

The rest of groups were treated with lead acetate (0.48 mmol/L in distilled water) orally daily for 8 weeks, the third group concomitantly administered L-arginine intraperitoneal injection while, the last group co administered L- N-Nitro-L-arginine methyl ester intraperitoneal injection (L^NAME).

Blood samples were collected at the 4"' and 8lh week of the study for biochemical analysis of mean blood lead level and serum nitric oxide, lipid peroxide, total antioxidants, HDL and LDL.

Measurements of systolic blood pressure were done.

RESULTS: The mean blood lead levels, lipid peroxidation levels and LDL- cholesterol of lead treated rats were significantly higher in all groups than control.

While the serum total antioxidant levels and HDL- cholesterol significantly decreased below control levels.

There was a positive correlation between mean blood lead and each of serum LDL, serum lipid peroxide and systolic blood pressure.

Moreover, a significant negative correlation was observed between serum nitric oxide and each of mean blood lead, serum LDL and systolic blood pressure.

CONCLUSION: These findings point to the role of nitric oxide (NO) in the pathophysiologic mechanisms of lead induced cardiovascular diseases and hypertension.