In vivo evaluation of interrelationship between hyperthyroidism and premature ejaculation

IN VIVO EVALUATION OF INTERRELATIONSHIP BETWEEN HYPERTHYROIDISM AND PREMATURE EJACULATION Dr. Ahmet CihanDokuz Eylul Universty, School of Medicine, Department of Urology, Inciralti, İzmir The aim of the current study is to investigate the effects of experimentally induced hyperthyroidism on the physiological parameters of ejaculation using p-Choloroamphetamine (PCA) induced ejaculation rat model. Twenty-eight male Wistar rats were used in the study. Rats were grouped by seven as hyperthyroid, recovery, control and sham group. Injection of L-Thyroxine (25?g/100g.bw) for 14 days was performed to induce hyperthyroidism. At the end of the injection period thyroid hormone status were evaluated by serum TSH measurements. Recovery group were recruited to operations after washout period to spontaneous recovery from hyperthyroidism for 28 days. During the injection period seven rats were injected subcutaneous saline (0.5mL/100g.bw) as a control group. Operations were performed after intraperitoneal 1.2gr/kg urethane administration. Rats underwent seminal vesicle (SV) catheterization and bulbospongiosus (BS) muscle dissection. Electromyographic (EMG) recordings of BS muscles and SV pressure measurements were performed in all groups before and after intraperitoneal administration of 5 mg/kg PCA. The time interval between PCA administration and first ejaculation were significantly reduced in hyperthyroid rat group (p= 0.001). Seminal vesicle phasic contraction frequency after PCA administration was significantly more than the other groups in rats with hyperthyroid state (p= 0.047). Mean AUC values of BS muscle EMG activities were elevated in this group (p= 0.0001). All of the parameters in recovery and control group rats were not significantly differed from each other. Both emission and expulsion phases of ejaculation are influenced by hyperthyroidism. Hyperthyroidism should be considered as a novel and reversible etiologic risk factor for PE. Keywords: Hyperthyroidism, premature ejaculation, ejaculation animal model