TADALAFIL RAISES THE RATE OF OXYGEN CONSUMPTION BY THE CELLS OF PROSTATE

Background: Tadalafil is the inhibitor of phosphodiesterase 5 type (PDE5). PDE5 is localized in caver- nosal tissue of penis. As of today it is considered to be proven that it is the reason of tadalafil's eff ectiveness in men with erectile dysfunction. Several years ago, it was estimated that tadalafil 5 mg is also effective in men with lower urinary tra ct symptoms (LUTS), which are associated with benign prostatic hyperplasia (BPH) and chronic prostatitis (CP ). But the level of this effectiveness in every patient is different, moreover it is poorly predictable and poorly explainable. Intimate molec ular mechanisms of tadalafil's clinical effectiveness in men with BPH and CP remain understood incompletely, becau se PDE5 is not the main subtype of PDE in prostate and in bladder. In 2016, we were the first, who estimated that the alpha - adre- noblocker doxazosin has one more mechanism of action: doxazosin raises the rate of oxygen consumption by the cells of prostate. We supposed that the mechanism of tadalafil's effectiveness in men with BPH is the same. The objective is to find one more mechanism of tadalafil effect in prostate. Design, materials and methods: 0.5 liter of distilled water (temperature = 36.6 ° С ) was po ured into two plastic cans. Every can was connected to polarographic device by the pair of electrodes. One crushed tablet of tadalafil (Cialis) 5 mg was submerged into the first can and none into the second can. 33 male rats were used. The prostate was resected from rats and divided into two parts with equal weight. Homogenate was prepared from every part. Further every homogenate was placed into the cans. The air-tightness was created. The circuit was closed under the voltage of 0.95 V. Current intensity (CI) was the same in both cans in the beginning of every experiment – 1.8 microampere. Outcome measurements and statistical analysis: synchronous comparison between the CI in two different cans with water in each moment of time. The first can contained 5 mg of tadalafil; the second one did not. The Wilcoxon's criteria was used. The results: it was detected that CI decreases much faster and more remarkably in those cans, where before homogenate immersion 5 mg of tadalafil was placed. Conclusion: tadalafil raises the rate of oxygen consumption by the prostate cells. In such way, tadalafil helps the prostate cells consume О2 supplied by blood. We consider that this is the reason why the clinical efficiency of tadalafil in men with BPH is individual.