Phenylguanine found in urine after benzene exposure.

Comparative investigations with synthetic N7-phenylguanine were carried out to clarify whether this compound is eliminated via the urine of rats as a benzene-derived nucleic acid adduct. As sensitive methods for detecting trace amounts of the compound, gas chromatography-mass spectroscopy, high performance liquid chromatography, and two immunoassays (enzyme-linked immunosorbent assay and fluoroimmunoassay) with appropriate monoclonal antibodies were used. The results indicate the excretion of several benzene-related guanine adducts slightly different from N7-phenylguanine that may possibly be hydroxylated.

Cardiac alterations at the myofibrillar level: is a redistribution of the myosin isoenzyme pattern decisive for cardiac failure in haemodynamic overload?

Cardiac muscle physiology, cardiac dynamics and energetics of normotensive and hypertensive rats [Goldblatt II, spontaneously hypertensive rats (SHR)] are analyzed in the light of the question of whether a shift in the isoenzyme pattern of myosin in favour of the isoenzyme VM-3--i.e., transformation towards a slower muscle--is the essential factor for manifestation of cardiac insufficiency under chronic haemodynamic overload.