Table 4. Analysis of micronucleus frequency in the small intestine.

Group	Micronuclei*
Untreated°	-
Histamine#	-
Untreated-5 Gy§	50±2a
Histamine-5 Gyˆ	30±2a,b

^*Chromosomal damage was measured by analysing micronucleus. The number of micronuclei was determined in 1000 cells and is expressed as mean ± SEM.

^#Representative of small intestines from at least eight 0.1 mg/kg.day histamine-treated rats;

^§Representative of small intestines from at least eight saline-treated and 5 Gy-irradiated rats;

^ˆRepresentative of small intestines from at least eight histamine-treated and 5 Gy-irradiated rats.

^aP<0.001 vs untreated,

^bP<0.001 vs untreated-5 Gy (ANOVA and Tukey Post test).