The distribution patterns of two forms of sulphotransferase were studied in human adult and fetal tissues. One form was studied with p-nitrophenol as substrate and it is referred to as 'TS'. The other form was studied with dopamine as substrate and it is referred to as 'TL'. The activities of TS (pmol X min-1 X mg-1; mean +/- SD) were 1,077 +/- 293 (adult liver; n = 6), 97.8 +/- 26.4 (fetal liver; n = 8); 38.0 +/- 12.8 (adult kidney; n = 5), 28.5 +/- 21.5 (fetal kidney; n = 8); 78.9 +/- 21.3 (adult lung, ex-smokers; n = 5), 83.0 +/- 23.1 (adult lung, smokers; n = 5), 25.8 +/- 10.0 (fetal lung; n = 8), 140.8 +/- 18.9 (ileum; n = 5), 68.6 +/- 30.7 (ascending colon; n = 5), 28.6 +/- 10.8 (fetal gut; n = 8), 23.9 +/- 14.5 (placenta; n = 5). The adult to fetal ratios for TS were 11.0 (liver), 1.3 (kidney), 3.1 (lung) and 2.6 (gut). The activities of TL were 28.9 +/- 17.4 (adult liver; n = 6), 97.2 +/- 52.3 (fetal liver; n = 8); 10.3 +/- 4.7 (adult kidney; n = 5), 37.7 +/- 29.9 (fetal kidney; n = 8); 79.6 +/- 18.8 (adult lung, ex-smokers; n = 5), 76.3 +/- 23.7 (adult lung, smokers; n = 5), 98.2 +/- 55.0 (fetal lung; n = 8); 391.2 +/- 37.3 (ileum; n = 5), 161.5 +/- 66.0 (ascending colon; n = 5), 200.6 +/- 137.1 (fetal gut; n = 8), 21.8 +/- 13.6 (placenta; n = 5).(ABSTRACT TRUNCATED AT 250 WORDS)