Salivary epidermal growth factor and intestinal adaptation in male and female mice

Salivary epidermal growth factor (sEGF) levels are increased in male mice a fter small bowel resection (SBR) and may be important during intestinal ada ptation. Since males have greater sEGF than females, the influence of sex o n postresection adaptation was tested. Females had lower sEGF; however, sEG F substantially increased in both sexes after a massive (50%) SBR. Adaptive increases in DNA and protein content, villus height, and crypt depth, as w ell as crypt cell proliferation rates in the remnant ileum, were not differ ent between males and females. Although significant postresection increases in sEGF were identified, EGF mRNA and protein did not change within the su bmandibular gland. Glandular kallikrein-13 and ileal EGF receptor expressio n were greater after SBR in female mice. Intestinal adaptation is equivalen t in female and male mice after SBR. Despite lower sEGF, females demonstrat ed increased expression of a kallikrein responsible for sEGF precursor clea vage as well as amplified ileal EGF receptor expression. These results endo rse an important differential response between sexes regarding sEGF mobiliz ation and intestinal receptor availability during adaptation.