Adipose derived stem cells ameliorate hyperlipidemia associated detrusor overactivity in a rat model.

PURPOSE

Adipose tissue derived stem cells can differentiate into muscle and neuron-like cells in vitro. We investigate the usefulness of adipose tissue derived stem cells for overactive bladder in obese hyperlipidemic rats.

MATERIALS AND METHODS

Hyperlipidemia was induced in healthy rats by a high fat diet. The resulting obese hyperlipidemic rats were treated with bladder injection of saline, adipose tissue derived stem cells or tail vein injection of adipose tissue derived stem cells. Bladder function was assessed by 24-hour voiding behavior study and conscious cystometry. Bladder histology was assessed using immunostaining and trichrome staining, followed by image analysis.

RESULTS

Serum total cholesterol and low density lipoprotein were significantly higher in obese hyperlipidemic rats than in normal rats (p <0.01). The micturition interval was shorter in saline treated obese hyperlipidemic rats than in normal rats, obese hyperlipidemic rats that received adipose tissue derived stem cells via the tail vein and obese hyperlipidemic rats that received adipose tissue derived stem cells by bladder injection (mean +/- SEM 143 +/- 28.7 vs 407 +/- 77.9, 281 +/- 43.9 and 368 +/- 66.7 seconds, respectively, p = 0.0084). Bladder wall smooth muscle content was significantly lower in obese hyperlipidemic rats than in normal animals (p = 0.0061) while there was no significant difference between obese hyperlipidemic groups. Nerve content and blood vessel density were lower in controls than in obese hyperlipidemic rats treated with adipose tissue derived stem cells.

CONCLUSIONS

Hyperlipidemia is associated with increased urinary frequency, and decreased bladder blood vessel and nerve density in rats. Adipose tissue derived stem cell treatment ameliorates these adverse effects and holds promise as a potential new therapy for overactive bladder.