Expression of Purinergic P2X2-receptors in Neurogenic Bladder Dysfunction Due to Spinal Cord Injury: a Preliminary Immunohistochemical Study

Study Design: Retrospective descriptive study.

Objective: Although muscarinic receptors are the main targets for the treatment of detrusor overactivity today, anticholinergic therapy is not satisfying in a substantial percentage of patients. Recently, overexpression of P(2)X(2) receptors in patients with idiopathic overactive bladder was demonstrated, indicating that purinergic innervation may play an important role in the pathophysiology of detrusor overactivity. We evaluated the expression of P(2)X(2) receptors in patients with spinal cord lesions.

Setting: German university hospital.

Methods: By immunohistochemical staining, the frequency and intensity of P(2)X(2) expression in bladder specimens from 15 patients with suprasacral spinal cord lesion were compared to those from 11 patients with bladder disorders not related to spinal cord injury (overactive bladder: n=6; chronic non-obstructive retention: n=2; bladder tumour: n=3).

Results: Specimens (12/15) from patients with spinal cord lesions and specimens (8/11) without spinal cord lesions demonstrated staining for P(2)X(2) receptors in the detrusor muscle and the urothelium. There was a tendency towards a stronger staining in specimens from patients with spinal cord lesion.

Conclusion: Our pilot study gives a first hint that the P(2)X(2) expression in patients with suprasacral spinal cord injury seems to be comparable to the expression in patients with idiopathic overactive bladder. Therefore, P(2)X(2) receptors in detrusor tissue may be a future target for the treatment of detrusor overactivity.