Atherosclerosis and hypertension induction by lead and cadmium ions: an effect prevented by calcium ion.

Abstract

In epidemiological studies, both positive and negative correlations have been found between cardiovascular disease and mortality and the presence of several inorganic ions in the drinking water. In an attempt to resolve this apparent disagreement, we exposed White Carneau pigeons to drinking water containing calcium (100 ppm), magnesium (30 ppm), lead (0.8 ppm), or cadmium (0.6 ppm) and used a 24-factorial design to measure the effects of these elements in atherosclerosis and hypertension. The results indicate that (i) lead and cadmium induced aortic atherosclerosis and hypertension, and (ii) calcium protects against the cardiovascular effects of cadmium. Furthermore, the effects of lead and cadmium were promoted by magnesium, and there were indications that magnesium antagonized the atherosclerotic protective effect ofcalcium. We suggest that, if these results with the pigeon can be applied to humans, the incidence of aortic atherosclerosis and hypertension should be significantly higher in areas where the drinking water contains magnesium, lead, and cadmium with a relatively low calcium concentration. Furthermore, if hard and soft water produce similar levels of lead and cadmium uptakes, the level of magnesium may be an additional factor in aortic atherosclerosis.Over the past 20 years, epidemiological and clinical evidence on the relationship between the quality of drinking water and the death rate from cardiovascular disease has been conflicting and inconclusive. Earlier studies correlated soft water with a higher cardiovascular death rate (1). Later studies showed a similar relationship but did not agree on the type of cardiovascular disease related to soft water. Various studies linked water softness to ischemic heart disease (2), to hypertension (3), to atherosclerosis (4), and to stroke (4). However, other studies do not confirm these observations (5, 6).Several specific elements in drinking water have been implicated in epidemiological studies of cardiovascular mortality.Noting that the relative concentration ofcalcium is lower in soft water than in hard water, several investigators studied the relationship between drinking-water calcium concentration and cardiovascular mortality and observed an increase in mortality when the relative concentration of calcium was lower (7). Furthermore, some studies have shown a higher incidence of cardiovascular mortality associated with consumption of soft water with relatively high concentrations of lead and cadmium (8). Again, however, other studies fail to confirm these correlations (9).The objective of the present studies was to determine the effects of calcium, magnesium, lead, and cadmium on the induction and progression of atherosclerosis and hypertension. We chose the male White Carneau pigeon (3 months ofage) for these studies because, unlike many other experimental models, it develops spontaneous atherosclerotic lesions ofboth the aorta and coronary arteries (10). METHODSMale pigeons 3 months ofage were housed indoors (in climatecontrolled, uncrowde...

Lead, blood pressure, and cardiovascular disease in men and women.

“…A large body of experimental data, both in vivo and in vitro, shows that lead increases blood pressure in several species of rats, pigeons, and dogs (13)(14)(15)(16)(17)(18). These studies have also documented increased reactivity to alpha adrenergic stimulation (14,16) and an interaction with calcium metabolism (15).…”

“…These studies have also documented increased reactivity to alpha adrenergic stimulation (14,16) and an interaction with calcium metabolism (15). Many ofthese studies examined several dose levels, and Victery (19) has summarized them as indicating biphasic response, with a strong effect of low-level exposure that disappears at high levels.…”

“…Cardiovascular outcomes seem likely to vary with duration as well as level of blood pressure change, suggesting a more cumulative exposure measure would be appropriate for them. Finally, it should be noted that Revis et al (15) found lead associated with atherosclerosis in pigeons. These findings, plus some ofthe direct cardiovascular effects noted by Kopp (25), also suggest that cumulative measures of lead may be important for assessing cardiovascular disease.…”

Assessment of Groundwater Quality in Southern Suburb of the Omdurman City of Sudan

“…Revis et al (1980) suggested that epidemiological and clinical incidence of atherosclerosis is higher in soft-water areas than in hard-water areas. However, Revis et al (1981) concluded various studies and linked water softness to ischemic heart disease, hypertension, atherosclerosis, and to stroke. Again, however, it was also reported by Revis et al (1981) that other studies do not confirm these observations to water softness.…”

“…However, Revis et al (1981) concluded various studies and linked water softness to ischemic heart disease, hypertension, atherosclerosis, and to stroke. Again, however, it was also reported by Revis et al (1981) that other studies do not confirm these observations to water softness. Singh et al (1993) documented that F -in drinking water affects negatively or positively human health and, to far extent, influenced by the ambient temperature, alkalinity, calcium and magnesium contents of drinking water.…”