EXPERIMENTAL-MODEL OF BLADDER OUTFLOW TRACT OBSTRUCTION IN THE GUINEA-PIG

Bladder outflow tract obstruction was produced in immature female guin ea-pigs. Obstruction caused an increase in voiding pressure and bladde r weight and a decrease in bladder compliance. No change occurred in t he sensitivity of obstructed detrusor strips to exogenous agonists, bu t the force of contraction and response to electrical stimulation of t he intrinsic nerves were less than in the strips from controls. The re sponse of strips from sham-operated animals to exogenous agonists and to electrical stimulation was greater than that from obstructed animal s. The effects of length and tension could not account for the in vitr o responses from obstructed animals. Histology after obstruction showe d muscle hypertrophy, connective tissue infiltration and decrease in n erve density. Many of the changes resembled those seen in the obstruct ed human bladder.