MeHg/PCB combination impairs motor skills in young rats.Roegge CS, Wang VC, Powers BE, Klintsova AY, Villareal S, Greenough WT, Schantz SL. 2004. Motor impairment in rats exposed to PCBs and methylmercury during early development. Toxicol Sci 77:315-324. Methylmercury (MeHg) and polychlorinated biphenyls polychlorinated biphenyls, (pol´ēklôr´  nā´tid bīfē´n (PCBs) both accumulate in the environment and in the tissues of fish. Both compounds have been linked to neurological and motor deficits in humans in a number of epidemiological studies. A study byresearchers at the FRIENDS Children's Environmental Health Center, a five-institute research consortium based at the University of Illinois at Urbana-Champaign Early years: 1867-1880The Morrill Act of 1862 granted each state in the United States a portion of land on which to establish a major public state university, one which could teach agriculture, mechanic arts, and military training, "without excluding other scientific College of Veterinary Medicine veterinary medicine, diagnosis and treatment of diseases of animals. An early interest in animal diseases is found in ancient Greek writings on medicine. Veterinary medicine began to achieve the stature of a science with the organization of the first school in the , provides new evidence that MeHg and PCBs act together to cause nervous system impairment. Among the researchers are NIEHS NIEHS National Institute of Environmental Health Sciences (NIH, DHHS) grantees Susan L. Schantz and Victor C. Wang of the University of Illinois at Urbana-Champaign. The researchers exposed female rats to low doses of MeHg, a PCB PCB: see polychlorinated biphenyl. PCB in full polychlorinated biphenyl Any of a class of highly stable organic compounds prepared by the reaction of chlorine with biphenyl, a two-ring compound. mixture, a combination of the two compounds, or control conditions starting 4 weeks prior to breeding and continuing through 16 days after birth Of offspring. The offspring of the groups were run through a battery of three motor skills tasks that involve cerebellar cerebellar /cer·e·bel·lar/ (ser?e-bel´ar) pertaining to the cerebellum. Cerebellar Involving the part of the brain (cerebellum), which controls walking, balance, and coordination. functions. Rat pups from the combined exposure group showed significant motor skill impairment in a test that involved traversing a rotating rod. Rats exposed to the PCB mixture alone were somewhat impaired, and rats exposed to MeHg alone were unimpaired Adj. 1. unimpaired - not damaged or diminished in any respect; "his speech remained unimpaired" undamaged - not harmed or spoiled; sound uninjured - not injured physically or mentally as compared to the control animals. There were no significant deficits related to PCB or MeHg exposure on the less complex tasks of vertical rope climbing or completing a parallel bar test. This study demonstrated that combined treatment with MeHg and PCBs may produced additive neurological effects. The researchers point out that PCB exposure contributed more to motor impairment than did MeHg, possibly due to the low dosage used. Rats exposed to MeHg alone demonstrated no significant impairments. The current study could offer an explanation as to why previous epidemiological studies of humans exposed to MeHg by eating contaminated fish have produced conflicting results. The scientists will continue their studies to determine if PCBs and MeHg have the same or independent mechanisms of action. |
|
||||||||||||||||
Printer friendly
Cite/link
Email
Feedback
Reader Opinion