Effects of chronic lead treatment on some cardiovascular responses to norepinephrine in the rat

Cardiovascular Actions of Lead and Relationship to Hypertension: A Review

“…Atrioventricular node excitability (A-H interval), Q-S intervale and heart rate were not affected significantly by lead treatment. These in vivo effects of lead generally parallel those reported in isolated perfused rat heart studies ( 20000 t susceptibility of the heart to ischemia-and catecholamine-induced arrhythmias (ectopic ventricular extrasystoles) has also been shown to be affected by chronic lead exposure (5,17,41). These effects have been demonstrated both in adult rats exposed to lead as neonates (5) and in adult rats exposed to lead (5 or 25 zg/mL drinking water) since weaning for 12 to 16 months (41).…”

“…Not surprisingly, the extent of the cardiac and vascular involvement appears to escalate as a direct function of the oral lead dose. In general, administration of lead, most commonly as the acetate salt, to experimental animals has been shown to induce myocarditis (42), degenerative structural and biochemical changes affecting the musculature of the heart and vasculature (35,37,42,43), hypertension (4,6,14,38-40), hypercholesterolemia (6,16,19,20), increased arterial plaque deposition (19,20), electrocardiographic disturbances (38,39), accentuated catecholamine-arrhythmogenicity (5,17,41), altered contractile responsiveness of the myocardium to inotropic stimulation (44), and increased vascular reactivity to cx-adrenergic agonists (5,17,41,44). Although incomplete, recent evidence suggests a role for calcium in the chronic and acute toxicity of lead in the cardiovascular system (6).…”

The Relationship of Blood Lead Levels to Blood Pressure in the U.S. Population

“…Dietary calcium has been inversely related to blood pressure, and calcium intake has been observed to ameliorate the toxic effects of lead exposure (14-18. A considerable body of physiologic data has accumulated that indicate blood pressure increases in animals fed small amounts of lead at exposures similar to human environmental exposures (18,19). Based on the long historical association and the provocative findings of blood pressure effects at low levels of lead exposure, we analyzed data from the National Health and Nutrition Examination Survey II (NHANES II) to determine if an association existed between relatively low blood lead levels and blood pressure (8).…”

The relationship of blood lead levels to blood pressure in the U.S. population.

“…Dietary calcium has been inversely related to blood pressure, and calcium intake has been observed to ameliorate the toxic effects of lead exposure (14)(15)(16)(17). A considerable body of physiologic data has accumulated that indicate blood pressure increases in animals fed small amounts of lead at exposures similar to human environmental exposures (18,19). Based on the long historical association and the provocative findings of blood pressure effects at low levels of lead exposure, we analyzed data from the National Health and Nutrition Examination Survey II (NHANES II) to determine if an association existed between relatively low blood lead levels and blood pressure (8).…”