Evidence that bremazocine prevents urine retention induced by intraspinal cord injection of colchicine in rats.

Intra-spinal cord injection of colchicine (2.5-5 micrograms/rat) produced an inhibition of reflex micturition leading to voiding suppression, bladder hypertrophy and overflow incontinence. Intraperitoneal administration of bremazocine, a kappa-receptor agonist with antagonistic properties for mu- and delta-receptors minimized the colchicine induced effects. The selective kappa-receptors agonist, U-69593, had little effect, while eledoisin or naloxone administration worsened rather than counteracted urine retention.