HISTOLOGICAL AND HISTOCHEMICAL-STUDY OF THE VESICOURETERAL JUNCTION IN INFANCY AND CHILDHOOD

The morphology of the vesicoureteric junction was compared using 19 po st mortem specimens obtained from male and female Afro-American and Ca ucasian children with an age range of 1 to 72 months (mean 4). All spe cimens were serially sectioned and the tissues processed using standar d histological and histochemical techniques (acetylcholinesterase {ACh E} and pseudocholinesterase {PChE}). The results failed to reveal any differences in the structure of the vesicoureteric junction with respe ct to age, sex and ethnic origins. The vesicoureteric junction compris ed 3 histologically and histochemically distinct smooth muscle compone nts. Ureteric muscle formed a complete inner layer rich in PChE which continued beyond the ureteric orifices to merge distally with the supe rficial trigone. An intermediate layer of muscle was also demonstrated whose constituent muscle cells possessed specific histological featur es and which was rich in both AChE and PChE, which is distinct from th at derived from the ureter and detrusor. The presence of detrusor musc le on the outer aspect of the juxtavesical segment of ureter rich in A ChE was also confirmed. While this study, using histochemical studies in infants and children, did not reveal any differences in the structu re of the vesicoureteric junction with respect to age, sex or ethnic o rigin, an intermediate layer of muscle was identified with histochemic al characteristics more like that of the male genital tract than that derived from the ureter or detrusor muscle.