Figure 4

Protein expression of TNF in the colon following six weeks of fractionated radiotherapy. A = control; B = 7.5 Gy; C = 15 Gy; D = 22.5 Gy; E = 30 Gy; F = 37.5 Gy G = 45 Gy. No staining was seen in the crypts of rats that had received no radiotherapy. There was an increase in protein expression of TNF after radiotherapy, particularly after 22.5 Gy and 30 Gy as indicated by the arrow, although the staining was not considered to be very strong.