Mechanisms by which a phytotherapeutic drug influences bladder activity in rats

We investigated the mechanisms by which Eviprostat, a phytotherapeutic drug for benign prostatic hyperplasia, influences bladder activity in rats.

A total of 42 female rats were divided into a control group and an Eviprostat group. Rats in the control group were fed a standard diet, while animals in the Eviprostat group were fed a diet containing 0.1% Eviprostat. After 2 weeks 14 rats (7 rats per group) underwent continuous cystometry with physiological saline or 0.1% acetic acid solution and bladder activity was recorded. Body weight, blood pressure, plasma monoamines and adenosine triphosphate were measured in another 14 rats (7 per group). In the remaining 14 rats (7 per group) 0.1% acetic acid solution was infused into the bladder and urinary adenosine triphosphate was measured before and after stimulation.

During cystometry with acetic acid the interval between bladder contractions was shorter and maximum bladder contraction pressure was higher in the control group compared with results obtained using physiological saline but such differences were not seen in the Eviprostat group. Plasma adrenaline and noradrenaline were lower in the Eviprostat group than the control group but no difference in blood pressure was observed. Urinary adenosine triphosphate was higher in the 2 groups than before stimulation but the increase was smaller in the Eviprostat group than in the control group.

These results suggest that Eviprostat acts to maintain low catecholamine and also inhibit pathological bladder activity by decreasing adenosine triphosphate release from the bladder.