Ohta H, Nakakita M, Tanaka H, Seki Y, Yoshikawa H
Department of Occupational Health and Toxicology, School of Allied Health Sciences, Kitasato University, Japan.
Ind Health. 1997;35(1):96-103. doi: 10.2486/indhealth.35.96.
The possible induction of a metallothionein (MT)-like Cadmium (Cd) binding protein (MT-like Cd-BP) was investigated in rat testis after oral Cd administration. Male Wistar rats were given Cd by oral administration (20 mgCd/kg, for 10 weeks), while the experimental controls were given Cd by intraperitoneal (i.p.) injection (2 mgCd/kg). Cd concentration increased in the testes after both administrations. However, much more Cd (about 4 times) accumulated in the tests of rats receiving oral Cd administration than in rats receiving Cd ip injection (experimental control). Meanwhile, MT-like Cd-BP decreased dramatically in the testes after Cd i.p. injection compared to that in the testes of untreated control rats. However, this testicular MT-like Cd-BP after oral Cd administration increased significantly up to about 1.4 times of the amount found in the testes of untreated control rats. Inhibition of glutathione S-transferase (GST) activity and decreased glutathione (GSH) in the testes was not observed in rats after oral Cd administration. However, enzyme activity and GSH concentration were inhibited and decreased significantly in the testis by Cd toxicity after Cd i.p. injection. These results indicate that testicular MT-like Cd-BP, assumed to be MT and to be hardly inducible by Cd, is an inducible protein corresponding to increased Cd accumulation in the testis without damage by Cd toxicity after oral Cd administration.
研究了口服镉后大鼠睾丸中可能诱导产生的一种金属硫蛋白（MT）样镉结合蛋白（MT样镉结合蛋白）。给雄性Wistar大鼠口服镉（20mg镉/千克，持续10周），而实验对照组通过腹腔注射镉（2mg镉/千克）。两种给药方式后睾丸中的镉浓度均升高。然而，口服镉的大鼠睾丸中积累的镉（约4倍）比腹腔注射镉的大鼠（实验对照组）多得多。同时，与未处理的对照大鼠睾丸相比，腹腔注射镉后睾丸中的MT样镉结合蛋白显著降低。然而，口服镉后睾丸中的这种MT样镉结合蛋白显著增加，高达未处理对照大鼠睾丸中发现量的约1.4倍。口服镉的大鼠未观察到睾丸中谷胱甘肽S-转移酶（GST）活性的抑制和谷胱甘肽（GSH）的降低。然而，腹腔注射镉后，镉毒性导致睾丸中的酶活性和GSH浓度显著受到抑制和降低。这些结果表明，睾丸中的MT样镉结合蛋白，假定为MT且难以被镉诱导，是一种可诱导的蛋白，对应于口服镉后睾丸中镉积累的增加，且不受镉毒性的损害。
