[Changes in mammary secretory epithelial reactions to oxytocin action under the influence of ouabain]

Changes in shape and volume of mammary secretory cells and in their RNA content, under the action of oxytocin, are considered. Under ouabain suppression of Na,K-ATPase activity, no swelling or shape changes occur in the secretory cells, in addition to no increase in their RNA content, which is characteristic of the cell reaction during the initial period of oxytocin action.