O6-Butylguanine was detected in the urine of rats given the butylating agent N-nitroso-N-butylurea. O6-Butylguanine contents in the 24-h rat urine samples after i.p. doses of 50, 100, and 200 mg/kg N-nitroso-Nbutylurea were 1.03 4. 0.41 (SE), 8.30 4. 1.70, and 59.53 4. 6.52 pmol, respectively. This suggests that O6-butylguanine formation in nucleic acids might be repaired in vivo, possibly by b...

Arecent flurry of research papers and commentaries in this journal1–4 has highlighted a current major controversy in cardiovascular biochemistry and physiology: how is nitric oxide (NO) transported in the bloodstream. Two views have arisen. First, that S-nitrosated hemoglobin and albumin serve as stable storage forms of intravascular NO, and, in the case of S-nitrosated hemoglobin, as an allost...

Three nitrosoalkylureas, two nitrosotrialkylureas, and three nitrosoalkylcarbamates were given to Syrian golden hamsters by gavage at approximately equimolar doses. Measured by the time to death with tumors as an index, nitrosoethylurea was the most potent carcinogen, followed by nitroso-2-hydroxyethylurea, which was less effective in males than in females. The least effective compounds, by thi...

Nitroglycerin dilates large (greater than or equal to 100 microns) but not small coronary arterial microvessels, and a putative metabolite of nitroglycerin, S-nitroso-L-cysteine, has been shown in vitro to dilate both large and small coronary microvessels. Based on this evidence, we tested the hypothesis that the lack of response of small coronary microvessels was due to an inability of small c...