MODIFICATION OF BLADDER STRUCTURE IN RESPONSE TO OUTFLOW OBSTRUCTION AND AGING

The morphology of the normal bladder has been compared with that of th e obstructed and the ageing bladder, using both fight and electron mic roscopy. In the normal bladder the smooth muscle cells are closely pac ked together with relatively little intervening connective tissue. The smooth muscle bundles are innervated predominantly by autonomic presu mptive cholinergic nerve fibres, while adrenergic nerves are usually o bserved in association with blood vessels. In the obstructed bladder, many smooth muscle cells are surrounded by large amounts of connective tissue and some of the muscle cells change their function from contra cting to seemingly being involved in collagen synthesis. A significant reduction in the innervation of the smooth muscle cells is observed. In the ageing bladder, the smooth muscle cells have a normal morpholog y which is in contrast to the findings in the obstructed bladder. A re duction in the innervation of the ageing bladder is observed, although to a considerably lesser extent than that observed in the obstructed bladder. As the morphology of the obstructed bladder differs from that of the ageing bladder, it is unlikely that the changes seen in the ob structed bladder simply reflect a function of age.