부산대학교 도서관

The effect of lead exposure on β2-adrenoceptor density and catecholamine response was studied in 26 male workers and 1 female worker, exposed to lead on average for 6 years. The systolic blood pressure in lead workers (101–160 mmHg, 124.4 ± 14.7 mmHg) was found to be significantly higher than in controls (97–134 mmHg, 115.4 ± 10.4 mmHg,p< 0.01) as was plasma norepinephrine (0.51 ± 0.1 μg/liter vs 0.24 ± 0.05 μg/liter,p< 0.01). The density of lymphocyte β2-adrenergic receptors (Bmax) in lead-exposed workers was 86% lower than that in controls (0.15 ± 0.08 vs 1.08 ± 0.29 fmol/0.1 × 106cells;p< 0.01). The dissociation constants (Kd) of [125I]iodocyanopindolol were 93.6 ± 42.6 and 87.9 ± 42.7 pMin lead-exposed workers and controls, respectively. Multiple linear regression analysis showed that elevation of systolic pressure was closely related to (a) blood lead levels, (b) decreased β2-adrenergic receptor density, and (c) increased plasma catecholamine levels in lead-exposed workers. Linear regression analysis revealed that both plasma norepinephrine levels and β2-adrenoceptor density (Bmax) were highly correlated with both systolic blood pressures and blood lead levels in lead-exposed workers, and a highly significant negative correlation was found to exist betweenBmaxand plasma norepinephrine levels (r= −0.82,p< 0.001). These data therefore demonstrate that there is a close relationship between elevated plasma catecholamine levels, decreased β2-adrenergic receptors, and elevated blood pressure in lead-exposed workers.