EFFECT OF UNDERNUTRITION ON THE DISTRIBUTION OF PROGESTERONE IN THE UTERUS OF EWES DURING THE LUTEAL-PHASE OF THE ESTROUS-CYCLE

The effect of undernutrition on ovarian and uterine venous progesteron e concentrations and endometrial progesterone content on Days 5 and 10 of the estrous cycle were studied. Forty ewes were synchronized using progestagen pessaries. At pessary withdrawal, the ewes were fed diets to provide either 1.5 or 0.5 times the daily maintenance requirement (Group H, n=20 and Group L, n=20, respectively). Ewes fed the low nutr ition diet (Group L) had higher mean peripheral progesterone concentra tions than those fed the high plane diet (Group H; P<0.05) but lower e ndometrial progesterone content on Day 5 (P<0.05). Neither ovarian nor uterine venous levels were affected by nutrition on either Day 5 or 1 0. Progesterone concentrations in blood samples collected ipsilateral to ovaries bearing a corpus luteum (CL) were higher than in the contra lateral samples (P<0.001). It is concluded that undernutrition can pro duce a reduction of endometrial content of progesterone the first week after mating. Since no differences in ovarian venous concentrations w ere observed, it remains to be shown whether this variation is due to other variables, such as the population of endometrial progesterone re ceptors or other nonhormonal factors. (C) 1998 by Elsevier Science Inc .