Effect of hemorrhage and nephrectomy on erythropoietin gene expression in the ovine fetus.

摘要

The purposes of this study were to determine whether (1) erythropoietin (Epo) gene expression could be stimulated, by severe hemorrhage, in both kidney and liver, at three stages of gestation (75-80, 106-112, and 140-142 days; term approximately equal to 150 days) in chronically-cannulated ovine fetuses and (2) whether the liver would compensate for the lack of kidneys at 110 days. Blood was removed (20% of estimated blood volume) at each of 0, 1, 19 h, and tissues collected at 24 h. In hemorrhaged fetuses (H) the liver mRNA levels were 2.7-, 5-, and 3-times that of control fetuses (C) at 78, 110 and 141 days, respectively. The kidney H:C ratios, for Epo mRNA, were 5, 6.4 and 43, respectively, at these three stages of gestation. In six fetuses at 108 days, nephrectomized 5-7 days before hemorrhage (HN) Epo mRNA increased 5-fold in the liver, and plasma Epo values were significantly lower (P < 0.05) than in intact (H). Thus hemorrhage stimulates increased Epo gene expression in both liver and kidney from mid-gestation, in the ovine fetus, but the liver does not compensate for the lack of kidneys at 110 days.