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1097. Cadmium the worst offender
540
PROCESSING AND PACKAGING CONTAMINANTS
PROCESSING AND P A C K A G I N G CONTAMINANTS 1096. Beryllium oxides--contrasting biological responses
Spencer, H. C., Jones, J. C., Sadek, S. E., Dodson, K. B. & Morgan, A. H. (1965). Toxicological studies on beryllium oxides. Toxic. appl. Pharmac. 7, 498. Several series of beryllium (Be) oxides were prepared by calcining crystalline a-Be hydroxide, amorphous fl-Be hydroxide and Be sulphate under various conditions of temperature and time. Striking differences were observed in the biological response of animals following intratracheal administration, depending on the sample of Be oxides used. For example, the lungs of rats treated with Be oxides produced by calcining a-Be hydroxide for 10 hr at 500°C showed a widely dispersed focal pneumonitis of granulomatous nature and tumours developed in the lungs after 7-8 months. Analyses showed a relatively high level of Be in the liver, kidney and bone. In contrast, the lungs of rats treated with Be oxides, produced by calcining cz-Be hydroxide for 10 hr at 1600°C showed minimal pathological changes, and very little if any Be was found in the liver, kidney and bone of these animals. 1097. Cadmium the worst offender
Schroeder, H. A. & Balassa, J. J. (1965). Influence of chromium, cadmium, and lead on rat aortic lipids and circulating cholesterol. Am. J. Physiol. 209, 433. Following lifetime administration of low levels of several metals in the drinking water of experimental animals, cadmium (Cd) and lead (Pb) were found to be toxic in terms of lifespan and mortality, whereas trivalent chromium (Cr nI) was beneficial (Cited in F.C.T. 1965, 3, 536). Moreover, Cd produced a high incidence of hypertension, renal arteriolar sclerosis and ventricular hypertrophy (ibid 1966, 4, 232) and Cd and Pb, but not Cr, depressed the concentration of serum cholesterol in young male rats (Schroeder & Vinton, Proc. Soc. exp. Biol. Med. 1962, 109, 859). The effects of lifetime administration of Cd, Pb and Cr m on serum cholesterol and aortic lipids are now reported. All three metals decreased the total serum cholesterol concentrations in male rats, although the effect of Cr m was not apparent until the animals were 17 months old. Only in the case of Cd was this effect associated with a marked increase in aortic lipid which might have been related to hypertension in these animals. For some unknown reason, although aortic lipids were similarly affected in female rats, the serum cholesterol level was not lowered and was, in fact, higher than in the control animals. In addition, plaques were found in the aortas of nearly 20 70 of the animals from control and Pb- and Cd-fed rats, but only in 1/48 animals receiving Cr IlK. These findings again show that Pb and particularly Cd are more toxic than Cr m. Cr m is known to increase hepatic synthesis of cholesterol and fatty acids (Curran, J. biol. Chem. 1954, 210, 765) and to stimulate fatty acid oxidation (Roginski & Mertz, Fedn Proc. Fedn Am. Socs exp. Biol. 1965, 24, 510), and the present results, which show that Cr nx decreases circulating cholesterol in male rats without affecting aortic lipid or producing plaques, suggest that Cr m may also influence the catabolism and/or excretion of cholesterol. 1098. This time on glucose Mertz, W., Roginski, E. E. & Reba, R.C. (1965). Biological activity and fate of trace quantities of intravenous chromium (III) in the rat. Am. J. PhysioL 209, 489. Low dietary levels of chromium (Cr) are beneficial to the growth and lifespan of experimental animals (Cited in F.C.T. 1965, 3, 536; ibid 1966, 4, 231). The effect of trivalent Cr (Cr IIx) on fat metabolism was discussed in the previous abstract; now it is the turn of the effect on glucose metabolism. Rats maintained on low-Cr diets received intravenous injections of 1-5 pg CrnI/kg either
PROCESSING AND PACKAGING CONTAMINANTS
PROCESSING AND P A C K A G I N G CONTAMINANTS 1096. Beryllium oxides--contrasting biological responses
Spencer, H. C., Jones, J. C., Sadek, S. E., Dodson, K. B. & Morgan, A. H. (1965). Toxicological studies on beryllium oxides. Toxic. appl. Pharmac. 7, 498. Several series of beryllium (Be) oxides were prepared by calcining crystalline a-Be hydroxide, amorphous fl-Be hydroxide and Be sulphate under various conditions of temperature and time. Striking differences were observed in the biological response of animals following intratracheal administration, depending on the sample of Be oxides used. For example, the lungs of rats treated with Be oxides produced by calcining a-Be hydroxide for 10 hr at 500°C showed a widely dispersed focal pneumonitis of granulomatous nature and tumours developed in the lungs after 7-8 months. Analyses showed a relatively high level of Be in the liver, kidney and bone. In contrast, the lungs of rats treated with Be oxides, produced by calcining cz-Be hydroxide for 10 hr at 1600°C showed minimal pathological changes, and very little if any Be was found in the liver, kidney and bone of these animals. 1097. Cadmium the worst offender
Schroeder, H. A. & Balassa, J. J. (1965). Influence of chromium, cadmium, and lead on rat aortic lipids and circulating cholesterol. Am. J. Physiol. 209, 433. Following lifetime administration of low levels of several metals in the drinking water of experimental animals, cadmium (Cd) and lead (Pb) were found to be toxic in terms of lifespan and mortality, whereas trivalent chromium (Cr nI) was beneficial (Cited in F.C.T. 1965, 3, 536). Moreover, Cd produced a high incidence of hypertension, renal arteriolar sclerosis and ventricular hypertrophy (ibid 1966, 4, 232) and Cd and Pb, but not Cr, depressed the concentration of serum cholesterol in young male rats (Schroeder & Vinton, Proc. Soc. exp. Biol. Med. 1962, 109, 859). The effects of lifetime administration of Cd, Pb and Cr m on serum cholesterol and aortic lipids are now reported. All three metals decreased the total serum cholesterol concentrations in male rats, although the effect of Cr m was not apparent until the animals were 17 months old. Only in the case of Cd was this effect associated with a marked increase in aortic lipid which might have been related to hypertension in these animals. For some unknown reason, although aortic lipids were similarly affected in female rats, the serum cholesterol level was not lowered and was, in fact, higher than in the control animals. In addition, plaques were found in the aortas of nearly 20 70 of the animals from control and Pb- and Cd-fed rats, but only in 1/48 animals receiving Cr IlK. These findings again show that Pb and particularly Cd are more toxic than Cr m. Cr m is known to increase hepatic synthesis of cholesterol and fatty acids (Curran, J. biol. Chem. 1954, 210, 765) and to stimulate fatty acid oxidation (Roginski & Mertz, Fedn Proc. Fedn Am. Socs exp. Biol. 1965, 24, 510), and the present results, which show that Cr nx decreases circulating cholesterol in male rats without affecting aortic lipid or producing plaques, suggest that Cr m may also influence the catabolism and/or excretion of cholesterol. 1098. This time on glucose Mertz, W., Roginski, E. E. & Reba, R.C. (1965). Biological activity and fate of trace quantities of intravenous chromium (III) in the rat. Am. J. PhysioL 209, 489. Low dietary levels of chromium (Cr) are beneficial to the growth and lifespan of experimental animals (Cited in F.C.T. 1965, 3, 536; ibid 1966, 4, 231). The effect of trivalent Cr (Cr IIx) on fat metabolism was discussed in the previous abstract; now it is the turn of the effect on glucose metabolism. Rats maintained on low-Cr diets received intravenous injections of 1-5 pg CrnI/kg either