Abstract
Cadmium-induced metallothionein (MT) synthesis was investigated in male rats of three ages, 3, 12 and 24 months. Physiological levels of MT in kidney, liver and lung measured simultaneously in untreated animals were found to be within the same range in all three age groups. Following 3-day treatment with CdCl2 equivalent to 1 mg/kg/day Cd, renal MT increased 10–15-fold in all animals. However, hepatic MT became elevated to 36 times the original value in the youngest (3-month-old) rats and 90 and 74 times, respectively, in the 12- and 24-month-old groups. Lung MT, which responded rather poorly to the cadmium inducer, increased 2-fold in the young group, but about 10 and 8 times, respectively, in the two older groups. High mortality of 75% occurred in the aged (24-month-old) group following cadmium administration, indicating age to be an important sensitizing factor in the toxic hazard of heavy metal exposure. The possible role in this connection of MT is discussed.
References
Bakka A, Webb M (1981) Metabolism of zinc and copper in the neonate: changes in the concentrations and content of thionein-bound Zn and Cu with age in the livers of newborn of various mammalian species. Biochem Pharmacol 30: 721–725
Bell JU (1979) A metallothionein-like protein in the hepatic cytosol of the term rat fetus. Toxicol Appl Pharmacol 48: 139–144
Bremner I, Williams RB, Young BW (1977) Distribution of copper and zinc in the liver of the developing sheep fetus. Br J Nutr 38: 87–92
Cherian MG, Goyer RA (1978) Metallothioneins and their role in the metabolism and toxicity of metals. Life Sci 23: 1–10
Eaton DL, Toal BF (1982) Evaluation of the Cd/hemoglobin affinity assay for the rapid determination of metallothionein in biological tissues. Toxicol Appl Pharmacol 66: 134–142
Ghanayem BI, Blair PC, Thompson MB, Maronpot RR, Matthews HB (1987) Effect of age on toxicity and metabolism of ethylene glycol monobutyl ether (2-butoxyethanol) in rat. Toxicol Appl Pharmacol 91: 222–234
Goering PL, Klaassen CD (1984) Resistance to cadmium-induced hepatotoxicity in immature rats. Toxicol Appl Pharmacol 74: 321–329
Hartmann H, Weser V (1977) Copper-thionein from fetal bovine liver. Biochim Biophys Acta 491: 211–216
Onosaka S, Cherian MG (1982) The induced synthesis of metallothionein in various tissues in rat in response to metals. II. Influence of zinc status and specific effect on pancreatic metallothionein. Toxicology 23: 11–20
Onosaka S, Tanaka K, Doi M, Okahara K (1978) A simplified procedure for determination of metallothionein in animal tissues. Eisei Kagaku 24: 128–133
Pinto RE, Bartley W (1969) The effect of age and sex on glutathione reductase and glutathione peroxidase activities and on aerobic glutathione oxidation in rat liver homogenates. Biochem J 112: 109–115
Riordan JR, Richards V (1980) Human fetal liver contains both zinc- and copper-rich forms of metallothionein. J Biol Chem 255: 5380–5383
Waalkes MP, Bell JU (1980) Isolation and partial characterization of native metallothionein in fetal rabbit liver. Life Sci 27: 585–593
Waalkes MP, Klaassen CD (1984) Postnatal ontogeny of metallothionein in various organs of the rat. Toxicol Appl Pharmacol 74: 314–320
Waalkes MP, Klaassen CD (1985) Concentration of metallothionein in major organs of rats after administration of various metals. Fund Appl Toxicol 5: 473–477
Wong KL, Klaassen CD (1979) Isolation and characterization of metallothionein which is highly concentrated in newborn rat liver. J Biol Chem 254: 12399–12403
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Wormser, U., Nir, I. Effect of age on cadmium-induced metallothionein synthesis in the rat. Arch Toxicol 62, 392–394 (1988). https://doi.org/10.1007/BF00293629
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00293629