02368naa a2200361 a 450000100080000000500110000800800410001902400380006010000160009824501400011426000090025452013310026365000190159465000170161365000140163065000170164465000170166165000100167865000290168865000190171765000220173665000100175865000120176865000170178065000170179765300170181465300240183170000180185570000130187370000180188670000150190477300870191915218642023-06-26       1978    bl uuuu     u00u1 u    #d7 a10.1016/0002-9378(78)90772-x2DOI1 aBURD, L. I.  aThe relationship of changes in mammary blood flow and plasma progesterone at the time of parturition in the ewe.h[electronic resource]  c1978  aPrevious studies indicate that there is a fall in maternal plasma pregesterone and a marked increase in mammary blood flow (MBF) at the time of parturition in ewes. In this experiment the role of progesterone as a cause of this increase in MBF was investigated. Progesterone was infused (9.9 mcg. per minute) into a branch of the mammary artery in five sheep during the induction of premature labor by fetal dexamethasone infusion (1 mg. per 24 hours) to prevent the normal fall in concentration of local mammary artery progesterone. Five ewes used as controls received a mammary artery infusion of cholesterol (9.9 mcg. per minute). In the cholesterol-infused group MBF increased significantly from baseline values after 13 mais ou menos 4 hours (mean mais ou menos standard error) to a peak flow of 235 mais ou menos 9 ml. per minute. In the group receiving the progesterone the increase in MBF was delayed to 35 mais ou menos 7 hours, reaching only 161 mais ou menos 22 ml. per minute. These results were significantly different from control group results (p&lt0,01). This study suggests that the fall in maternal plasma progesterone which occurs at the time of parturition may play a role in the increase in MBF that occurs prior to the onset of labor, delivery, and lactogenesis. (AM. J. OBSTET. GYNECOL. 132: 385, 1978).  aMammary glands  aPharmacology  aPregnancy  aProgesterone  aReproduction  aSheep  aCirculação Sangüínea  aEndocrinologia  aGlândula Mamaria  aOvino  aPrenhez  aProgesterona  aReprodução  aBlood supply  aRegional Blood Flow1 aTAKAHASHI, K.1 aWARD, K.1 aASCHERMAN, G.1 aDOWERS, S.  tAmerican Journal of Obstetric and Ginecologygv. 132, n. 4, p. 385-391, Oct. 1978.