Colon tumors localization, incidence, multiplicity and size in rats exposed to 1,2-dimethylhydrazine (DMH) and metformin
| Parameters | Treatment | ||
| DMH + water | DMH + metformin, 100 mg/kg | DMH+metformin, 300 mg/kg | |
| No. of rats | 8 | 9 | 7 |
| Ascending colon | |||
| No. of tumor-bearing rats | 5 (63%) | 0 | 2 (29%) |
| No. of tumors | 5 | 0 | 5 |
| No. of tumors per tumor-bearing rat | 1.0 | 0 | 2.5 |
| Mean size of tumors, mm2 | 47±37.8 | 0 | 13±8.5* |
| Descending colon | |||
| No. of tumor-bearing rats | 8 (100%) | 6 (67%) | 6 (86%) |
| No. of tumors | 23 | 12 | 19** |
| No. of tumors per tumor-bearing rat | 2.9 | 2 | 3.2 |
| Mean size of tumors, mm2 | 93±79.5 | 37±31.2* | 43±23.9* |
| Rectum | |||
| No. of tumor-bearing rats | 2 (25%) | 2 (22%) | 2 (29%) |
| No. of tumors | 2 | 2 | 2 |
| No. of tumors per tumor-bearing rat | 1 | 1 | 1 |
| Mean size of tumors, mm2 | 26±24.9 | 49±37.3 | 146±66.8 |
| Total colon | |||
| No. of tumor-bearing rats | 8 (100%) | 7 (78%) | 6 (86%) |
| No. of tumors | 30 | 14 | 26 |
| No. of tumors per tumor-bearing rat | 3.75 | 2.0 | 4.8 |
| Mean size of tumors, mm2 | 81±72.9 | 39±27.5* | 45±22.7* |
The difference in the parameter for rats exposed to DMH+water is significant, *P<0.01; The difference in the parameter for the group DMH+metformin–100 is significant as well: **P<0.01.