The aim of the present work was the characterization of the myometrial samples of healthy control and chronic inflammation-exposed rats as a function of gestational stage by means of differential scanning calorimetry (DSC). Non-pregnant. mid-pregnant (day 14) and late-pregnant (day 21) animals were included. The spontaneous, KCl-stimulated as well as maximal motor activity was additionally recorded in vitro. Calorimetric enthalpy (Delta H) normalised on wet mass significantly increased as pregnancy progressed in case of non-inflamed uteri. Inflammation resulted in a significant decrease in Delta H/m of samples from non-pregnant till pregnant rats. Maximal contractility increased by inflammation in all tested stages of gestation. Our present results indicate that DSC can be considered as a useful tool for the investigation of the uterine function modified by gestation or a pathological condition. (C) 2009 Elsevier B.V. All rights reserved.