We previously reported that
lactose handling was significantly improved during late-phase pregnancy in women with a genetically determined adult-type
hypolactasia. However, the adaptive mechanisms underlying the enhanced
lactose digestion during pregnancy are not clear.
Progesterone therapy has been associated in animals with increased intestinal
lactase activity. To investigate the potential role of
progesterone and
estrogen as modulators of human
lactase activity during pregnancy, we employed the human-derived intestinal epithelial Caco-2 cell line. Measurements of
lactase and
sucrase activities were performed in parallel with
DNA content in
progesterone- and
estrogen-treated cells after 5, 10, and 30 days of confluency. Caco-2 monolayer
DNA content was observed to increase with duration of culture to an equivalent extent in both
hormone-treated and control cultures.
Lactase and
sucrase activities were similarly unaltered by incubation with either
progesterone or
estrogen, at any time point tested. These data demonstrate that gestational
hormones do not influence intestinal cell number nor
disaccharidase activity in Caco-2 cells, at the doses tested. Although these studies were carried out in a malignant cell line, our data suggest that the improved
lactose handling observed during pregnancy is probably related to prolonged intestinal transit.