Improving the voding dysfunction by a 5-HT1A receptor agonist in rats with chronic spinal cord injury / 中华泌尿外科杂志

ABSTRACT

Objective To investigate the effect of 5-hydroxytryptamine serotonin receptor-1A (5-HT1 A) agonists on micturition dysfunction in rats with chronic spinal cord injury (SCI).Methods Female SD rats weighing 175 -200 g were used.Seven of the rats were modified for a spinal cord injury model (transsection at T10).Eight weeks later,control rats and SCI rats were tested.Rats were anesthetized with urethane ( 1.3 g/kg ).A polyethylene (PE) -50 catheter was placed in the left jugular vein for intravenous drug administration.A PE-90 catheter was inserted through the bladder dome,and the other end of the bladder catheter was connected to a syringe pump for continuous infusion of saline and to a pressure transducer for intravesical pressure monitor.Dose-response curves for 8-OH-DPAT were followed by the WAY-100635 test.The capacity,residual volume,micturition volume,and EUS-EMG were measured.Results With an increasing dose of 8-OH-DPAT,the capacity of the bladder decreased from 33.2 ± 8.3 ml to 22.8 ± 2.4 ml.The micturition volume was increased from 0.14 ± 0.08 ml to 0.38 ± 0.09 ml.The residual volume decreased from 3.68 ± 1.36 ml to 1.84 ± 0.21 ml,and peak intravesical pressure changed from 27.1 ± 3.6 mm Hg to 22.8 ± 2.4 mm Hg.Control rats showed little significant change in the cystometric variable.Effects of 8-OH-DPAT were reversed by WAY-100635.That 8-OH-DPAT induced phasic relaxation occured in spinal cord-injured rats but the control group showed no significant change.ConclusionsThe 5-HTIA/7 receptor agonist 8-OH-DPAT may induce periodic EUS relaxation during voiding in urethane-anesthetized chronic spinal cordinjured rats.And this could result in an increase in micturition volume,a decrease in bladder capacity,and thus an increase in voiding efficiency.