A carcinogenic heterocyclic amine, 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), was measured in condensate of cigarette mainstream smoke by HPLC. PhIP was detected in all brands of filter-tipped cigarettes analyzed. The mean level of PhIP in the cigarette mainstream smoke was 16.4 ng/cig.

A bt~stract. A frequent manifestation of longterm glucocorticoid administration is the occurrence of posterior subcapsular cataracts. The molecular basis for this effect has not yet been elucidated. The addition of prednisolone to the rat lens in culture results in a timeand concentration-dependent lens opacification that correlates with the formation of covalent prednisolone-lens protein adducts. Prednisolone adduct formation was analyzed by [3H]prednisolone incorporation and by immunoprecipitation with antiserum specific for proteins modified by the nonenzymatic addition of prednisolone.In the rat lens, these adducts were localized in both the water-soluble and urea-soluble lens protein fractions. Gel electrophoresis and fluorography revealed that the most extensively modified proteins were two crystallins subunits. Lens proteins from 33 normal and cataractous human lenses were fractionated and analyzed for the presence of prednisolone-protein adducts by competitive radioimmunoassay. Adducts were detected only in those samples derived from glucocorticoid-induced cataractous lenses. We conclude that elevated glucocorticoid levels lead to the formation of glucocorticoid-lens protein adducts both in vitro and in vivo. Lens protein modification by glucocorticoids may lead to sufficient biochemical or structural alterations so as to result in cataract formation. The ability of glucocorticoids to form adducts with proteins in vivo also may play a role in some of the other toxic manifestations of long-term glucocorticoid therapy.

A carcinogen, 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), was measured in beer and wine by HPLC. PhIP was found to be present in all brands of beer and wine analyzed. The concentrations of PhIP in beer and wine were 14.1 +/- 6.18 ng/l (mean +/- SD, n = 11) and 30.4 +/- 16.4 ng/l (n = 10) respectively.

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