Galangin protects pig detrusor nerves from repetitive field stimulation and anoxia/glucopenia injury

OBJECTIVES: To test the capability of the flavonoid galangin to protect pig urinary bladder from damage due to a period of repetitive field stimulation as well as a period of anoxia/glucopenia and reperfusion. METHODS: Smooth muscle strips of the pig bladder were mounted for tension recording in small organ baths and the strips underwent either 1.5 hours of repetitive field stimulation at 32 Hz for 15 seconds every 5 minutes or under anoxia/glucopenia and reperfusion conditions. Galangin, at different concentrations, was added to the reperfusion Krebs solution to check the effect of this flavonoid compared with untreated strips under the same conditions. A group of experiments was performed to examine its possible underlying mechanisms. RESULTS: Repetitive field stimulation for 1.5 hours caused a progressive decrease in the maximal contractile response to electrical field stimulation (34% decrease). Galangin (10(-7) M) partially prevented the progressive decrease in the contractile response. This effect was significantly reduced when verapamil was added to the solution. Galangin significantly improved the response of strips to electrical field stimulation under anoxia/glucopenia and reperfusion conditions compared with untreated tissues. CONCLUSIONS: Galangin has a protective effect on bladder contractility by an action that at least, in part, depends on l-type calcium channels. Furthermore, galangin protects detrusor nerves against the anoxia/glucopenic and reperfusion damage.