Substrate (100 μm | 1 | 2 | 3 | 4 |
---|---|---|---|---|
pmol/mg/min | ||||
1-Naphthol | 182.9 | 74.3 | 299.3 | 71.8 |
4-Nitrophenol | 86.3 | 28.18 | 120.2 | 64.8 |
4-Methylumbelliferone | 82.5 | 30.2 | 129.1 | 62.4 |
4-Isopropylphenol | 31.8 | 8.2 | 29.5 | 25.2 |
Octyl-gallate | 35.3 | 16.2 | 26 | 25.5 |
Estriol | 13.8 | 8.1 | 11.9 | 14.3 |
Estrone | 13.9 | 5 | 12.9 | 16.9 |
Naringenin | 23.8 | 8.7 | 23.7 | 32.2 |
7-OH-benzo[α]pyrene | 33.5 | 9.3 | 27 | 36.5 |
Hyodeoxycholic acid | 147.1 | N.D. | N.D. | N.D. |
Gastric microsomal protein (25 μg) prepared from four individual gastric tissue specimens (1-4) were analyzed for glucuronidation activity as described in Materials and Methods. Sample 1 corresponds to Figure 3C, sample 2 to Figure 3B, sample 3 to Figure 3D, and sample 4 to Figure 3A. 14C-labeled glucuronides were separated by thin layer liquid chromatography and visualized after exposure to X-ray film. The glucuronides were scraped and quantified by liquid scintillation counting to determine specific catalytic activities. Only sample 1 exhibits catalytic activity toward hyodeoxycholic acid. The other specific activities vary 2- to 4-fold among the four samples, demonstrating a polymorphism of catalytic UGT activity in human gastric epithelium.
N.D., not detected.