THE PATHOPHYSIOLOGY OF CONTRACTILE ACTIVITY IN THE CHRONIC DECENTRALIZED FELINE BLADDER

Autonomous wave activity occurs in the decentralized bladder and may c ontribute to upper tract damage and incontinence. In order to clarify the poorly understood pathophysiology and neuropharmacology of autonom ous waves, cats were prepared with L7-S3 ventrodorsal rhizotomy alone or with L7-S3 ventral rhizotomy with and without total sympathectomy. The incidence of autonomous waves was <15% 12 weeks after ventral or v entrodorsal rhizotomy, but acute sympathectomy at 13 weeks increased t he incidence to 58% in these groups. With chronic sympathectomy the in cidence was 100%. This suggests that the waves arise locally via a mec hanism which is independent of L7-S3 dorsal roots, due to lack of a su ppressive sympathetic pathway. Autonomous waves were inhibited by atro pine after acute sympathectomy and by prazosin after chronic sympathec tomy, but increased inhibition occurred after both drugs in either cas e. Adrenergic neuron depletion with 6-hydroxydopamine enhanced wave ac tivity, which was incompletely inhibited by subsequent atropine. This implies that the peripheral reflex pathway has facilitatory al-adrener gic, muscarinic and also noncholinergic nonadrenergic elements. Clinic ally, sensory or sympathetic damage caused incontinence, but sympathec tomy also caused high pressure waves, which may cause upper tract dama ge and treatment resistant incontinence in patients.