Effect of PCB's on plasma vitamin A (retinol) and hepatic retinyl palmitate hydrolase (RPH) activity in female Sprague-Dawley rats
A single i.p. dose of 15, 5 or 1 mg/kg 3,4,3',4'-tetrachlorobiphenyl (TCB) caused a dose-dependent depression of plasma retinol levels 24 hours after treatment of female Sprague-Dawley rats. The loss of plasma retinol appeared to be a function of depressed levels of the retinol-retinol binding protein (RBP)-transthyretin ternary complex. No free retinol-RBP was observed in plasma from treated animals. Hepatic RPH activity was also depressed, and highly and positively correlated to the plasma retinol levels. TCB was determined to be a non-competitive inhibitor of partially purified RPH with a KI of 91 uM. Metabolism of TCB by microsomes in vitro decreased the inhibition of RPH. Equimolar doses of either 2,4,5,2',4',5'-hexachlorobiphenyl (HCB) or 3,4,5,3',4',5'-HCB failed to cause a similar depression of plasma retinol of treated female rats. They conclude that, unlike other PCB congeners, TCB causes a depression of plasma retinol by inhibition of hepatic RPH.
- Research Organization:
- Michigan State Univ., East Lansing
- OSTI ID:
- 6060581
- Report Number(s):
- CONF-870644-
- Journal Information:
- Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States), Vol. 46:6; Conference: 78. annual meeting of the American Society of Biological Chemists conference, Philadelphia, PA, USA, 7 Jun 1987
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
HYDROLASES
ENZYME ACTIVITY
POLYCYCLIC AROMATIC HYDROCARBONS
BIOLOGICAL EFFECTS
METABOLISM
VITAMIN A
BIOSYNTHESIS
DOSE-RESPONSE RELATIONSHIPS
INHIBITION
LIVER
MICROSOMES
RATS
ANIMALS
AROMATICS
BODY
CELL CONSTITUENTS
DIGESTIVE SYSTEM
ENZYMES
GLANDS
HYDROCARBONS
MAMMALS
ORGANIC COMPOUNDS
ORGANOIDS
ORGANS
RODENTS
SYNTHESIS
VERTEBRATES
VITAMINS
560300* - Chemicals Metabolism & Toxicology