Renal preservation despite 35 days of partial XXXX in the fetal lamb.

@entity742 @entity1621 @entity101 @entity1494
To determine whether the @entity101 and preservation of renal function that we demonstrated after 10 days of chronic partial @entity1494 in the third trimester fetal lamb also occur after earlier longer obstruction, we modified our preparation and studied the effects of 35 days of obstruction begun during the second trimester. Partial @entity1494 was created in 10 fetal @entity742 at 90 days of gestation (term equals 147 days). At repeat surgical intervention 28 days later vascular catheters and a left renal artery flow transducer were placed, and catheters were externalized. We then studied renal blood flow and function at gestational ages 120 days and 125 days after 30 days and 35 days of obstruction, respectively. Tissue was obtained for histology at the time of sacrifice. Eight control fetal @entity742 without obstruction were studied in a similar way. @entity1621 was noted in all fetal @entity742 after @entity1494 of the control animals had a normal appearance. Renal blood flow was higher in the obstructed fetal @entity742 than in controls (20.2 +/- 4.9 versus 10.2 +/- 0.9 ml. per minute per kg., p < 0.05 after 30 days and 17.1 +/- 2.7 versus 9.7 +/- 0.9 per minute per kg., p < 0.05 after 35 days). There was no evidence of decreased renal function by any parameter and, in fact, glomerular filtration rate and urine volume were increased after 30 days of obstruction (1.59 +/- 0.32 versus 0.69 +/- 0.07 ml. per minute per kg., p < 0.05 and 15.7 +/- 4.3 versus 5.2 +/- 0.8 ml. per hour per kg., p < 0.05, respectively). Histological studies demonstrated normal architecture of the kidneys but thinned cortex. We conclude that the physiological responses of the fetus are such that partial lower urinary tract obstruction in our preparation results in a prolonged @entity101 and preservation of renal function.
