Ontogeny of bladder compliance

Abstract

AbstractRecent advances in technology have allowed for the diagnosis of many urologic abnormalities through the use of antenatal ultrasonography. There is great debate in the pediatric literature as to whether the hydronephrosis which is diagnosed via antenatal ultrasound is always secondary to obstruction, or in certain cases represents a benign dilatation. Benign dilatations are postulated to be secondary to the increased fetal diuresis and a more compliant fetal urinary tract. In this study we present evidence for a gradual decline in bladder compliance with maturation. A summary of our results demonstrates that bladders obtained from 1 day old rabbits are 2 and 3 times more compliant than bladders of 4–8 week old rabbits. Active tension reaches a peak when the muscle is stretched to 150% of its initial resting length. However, 1 day old bladder tissue exhibits a higher active tension in response to field stimulation when compared to the response of bladder tissue obtained from 4 and 8 week old rabbits. In summary, compliance and active tension decrease with maturation.