R S Bhatnagar — Page 5

PubMedDate not supplied

Increased aryl hydrocarbon hydroxylase and prolyl hydroxylase activities in lung organ cultures exposed to benzo[a]pyrene.

Exposure of neo-natal rat lungs in organ culture to 10--25 microM benzo[a]pyrene (BaP) elevated the activities of aryl hydrocarbon hydroxylase (AHH) and prolyl hydroxylase (PH). Pyrene, a non-carcinogenic hydrocarbon did not elicit this response. Prolyl hydroxylase is an indicator of collagen synthesis and increased PH activity in the lungs reflects increased collagen synthesis. Our studies suggest that the earliest events in BaP-induced lung injury may include altered collagen metabolism.

Animals↗

PubMedDate not supplied

Inhibition of creatine kinase activity and alterations in electrophoretic mobility by palladium ions.

The toxicological consequences of increased levels of palladium in the environment have not yet been assessed. In this paper, the effect of palladium ions (Pd) on purified rabbit muscle creatine kinase (CPK-MM) and on human serum CPK-MM was examined. When rabbit muscle CPK-MM was treated with Pd, a concentration-dependent inhibition of enzyme activity with a calculated Ki of 0.16 mumol, associated with a marked increase in a electrophoretic mobility of the enzyme toward the anode, was observed. Pd exerted the same effect of human serum CPK-MM, but to a lesser extent. Analysis of binding of Pd to CPK-MM by a colorimetric competitive-binding technique, using chlorpromazine-chromophore, as well as by a dialyzing technique, indicated that the cation may form an extremely strong complex with essential SH groups of the enzyme.

Animals↗