Methyl mercury: acute toxicity, tissue distribution and decay profiles in the guinea pig |
| |
Authors: | F Iverson R H Downie C Paul H L Trenholm |
| |
Affiliation: | Pharmacology Division, Research Laboratories, Health Protection Branch, Department of National Health and Welfare, Ottawa, Canada K1A 0L2 |
| |
Abstract: | Acute toxicity studies with methyl mercuric chloride showed that the guinea pig was quite susceptible to methyl mercury intoxication. LD50 values were 5.5 mg Hg/kg ip and 16.5 mg Hg/kg po. One to 2 weeks after dosing, several animals began to display signs of neurotoxicity.Tissue distribution and pharmacodynamic studies with radiolabeled methyl mercuric chloride ([203Hg]CH3HgCl) at 1 and 10 mg Hg/kg revealed that while most tissues decreased in mercury concentration from day 1 to day 7, cerebrum, cerebellum and muscle showed a delayed uptake of the alkyl mercurial. In CNS tissue the concentration of mercury decreased in the order cerebrum > cerebellum > spinal cord. Kidney and liver consistently contained the highest levels of mercury, and plasma the lowest, during the 49-day sampling period. One week after dosing the blood: brain ratios were less than 1. The tissue concentration of mercury was generally directly proportional to the dose administered; however, mercury levels in the gall bladder were significantly higher than anticipated on 5 of the 7 sacrifice days.Most of the tissues displayed a biphasic decay profile with a half-life of 2–3 days for the initial rapid phase of decline. This initial phase was followed by a slower tissue excretion rate for which the mean half-life for mercury was 15 ± 0.9 days and 15 ± 0.8 days for the low and high dose, respectively. The similarity of these values again indicates no dose-related effects. |
| |
Keywords: | |
本文献已被 ScienceDirect 等数据库收录! |
|