Polybrominated biphenyl toxicosis in the rat and mouse

Abstract

Rats and mice were given 22 oral doses of Firemaster FF-1 or pure 2,2′,4,4′,5,5′-hexabromobiphenyl (HBB) over a 30-day period and held for 90 additional days to determine the pathobiological manifestations of toxicity. Female mice and rats given Firemaster FF-1 became porphyric after 45 and 120 days, respectively. The liver was enlarged due to swelling of hepatocytes, fatty infiltration and proliferation of endoplasmic reticulum. There was a marked increase in serum protein which was primarily due to β-globulin fraction in the rat. γ-Glutamyl transpeptidase was elevated in female rats in both groups given Firemaster FF-1 and HBB. A significant dose related increase in serum glutamic pyruvic transaminase was found in male rats at Day 60 only. There was a decrease in the packed cell volume accompanied by a proportional decrease in hemoglobin and red blood cell values in male rats given 30 mg of FF-1 at 30 and 45 days but returned to normal at 60 and 90 days. Hepatocellular alterations in rats and mice given FF-1 at 30.0 mg/kg (22 total doses) persisted when examined at 120 days. FF-1 was more toxic than pure HBB as determined by measurement of porphyrins and pathologic findings. Rats or mice treated with HBB tended to recover when examined during postexposure periods.