Intestinal iron absorption and mucosal transferrin in rats subjected to hypoxia.

Three days hypoxia (0.5 atm) increased the haemoglobin and haematocrit values in rats paralleled by enhanced intestinal iron absorption. The destination of recently-absorbed iron was primarily the erythropoietic system, viz. bone marrow, spleen and red cells. Total plasma transferrin, was increased by 30%, but no significant changes in mucosal transferrin were found. No increase in labelling of mucosal transferrin by absorbed iron was observed. These results suggest that mucosal transferrin does not play a major role in the regulation of intestinal iron absorption in hypoxia.