The Effect of Long-Term Tamsulosin Monotherapy and Tamsulosin - Dutasteride Combination Therapy on PKC-α Enzyme Expression in Prostate Stromal Tissue.

Background: The α-adrenergic receptor antagonist is the most effective medical therapy to reduce the dynamic component in patients with BPH. However, long-term administration of receptor antagonists can cause upregulation of mRNA receptor expression, resulting in tolerance of drug effectiveness. PKC-α is involved in the process of prostate smooth muscle contraction through activation of the voltage-gated Ca2+ conducted canal, influenced by androgen hormones, especially testosterone, and has an isoform with Twist1, a transcription factor that plays a role in up-regulation of androgen receptors.

Objective: The aim of the study was to compare the effect of long-term tamsulosin monotherapy and tamsulosin - dutasteride combination therapy in PKC-α enzyme expression in prostate stromal tissue of Rattus norvegicus rats of Wistar strain.

Methods: Out of 80 samples of Rattus norvegicus rats were divided into 8 groups with different interventions: negative control group, positive control group, tamsulosin monotherapy administration for 1 day, 3 day, and 6 day groups, and tamsulosin - dutasteride combination therapy for 1 day, 3 day, and 6 day groups. BPH was induced with 3 mg/kg of testosterone proprionate for 3 weeks, continued with drugs administration according to intervention grouping. Prostate stromal tissue was taken and prepared for PKC-α enzyme measurement with ELISA method.

Results: There was a significant difference (p<0.05) in the effect of tamsulosin monotherapy and tamsulosin-dutasteride combination therapy on the PKC-α expression. There was a strong positive relationship between the duration of tamsulosin-dutasteride combination therapy on the PKC-α expression, which means the longer the duration of the combination of tamsulosin-dutasteride combination the higher the PKC-α expression.

Conclusion: Administration of long-term tamsulosin - dutasteride combination therapy causes upregulation PKC-α expression more than tamsulosin only.