Investigation of the effects of nesfati̇n-1 on respiratory parameters and electrocardiography in rats

Investigation of the effects of nesfatin-1 on respiratory parameters and electrocardiography in rats In this study, it was aimed to investigate the effect of centrally and peripherally administered nesfatin-1 on respiratory parameters and electrocardiography (ECG) of healthy both fasted rats for 12 h and satiated rats fed ad libitum. In this study, 56 male Sprague Dawley rats weigthing 250-300 g were used. Under ketamine (50 mg/kg; im) and xylazine (20 mg/kg; im) anesthesia mix, all rats were tracheostomized to be monitored the respiratory parameters. To examine the ECG values, electrodes were placed in all rats so that a D II lead record was taken. In the first protocol of the study; the guide cannula prepared from 22 G stainless steel needle was inserted into the lateral cerebral ventricle (lcv) for centrally drug injections. The effect of centrally injected nesfatin-1 (100 and 200 pmol; lcv) in both satiated rats fed ad libitum and fasted rats for 12 h on respiratory parameters such as tidal volume (TV), respiratory rate (RR) and respiratory volume per minute (RVM), and ECG values such as P wave, P-R interval, QRS complex, T-wave, Q-T interval and two R-wave periods duration were investigated. In the second protocol of the study, the effect of nesfatin-1 (80 μg/kg) injected via tail vein of rats for peripheral effects of nesfatin-1 in both satiated rats fed ad libitum and fasted rats for 12 h on respiratory parameters such as tidal volume (TV), respiratory rate (RR) and respiratory volume per minute (RVM), and ECG values such as P wave, P-R interval, QRS complex, T-wave, Q-T interval and two R-wave periods duration were investigated. Centrally administered different doses of nesfatin-1 resulted in dose and time dependently statistically significant increase (p <0.05) in the TV, RR and RVM of satiated rats fed ad libitum and fasted rats for 12 h. Peripheral administration of nesfatin-1 (80 μg/kg; iv) in satieted rats ad libitum-fed caused a statistically significant increase (p <0.05) in RR and RVM, while no change occurred in the TV. Both lcv and iv administered nesfatin-1 in fasted rats for 12 h and satiated rats fed ad libitum led to time dependently statistically significant increase (p <0.05) in the T wave, QT interval, and RR interval duration without changing in P wave, PR interval and QRS complex duration. Moreover, lcv administered nesfatin-1 in fasted rats for 12 h and satiated rats fed ad libitum and iv injected nesfatin-1 in satiated rats fed ad libitum also induced statistically significant decrease in heart rate (p <0.05). In conclusion, these findings suggest that centrally and peripherally administrated nesfatin-1 caused hyperventilation in rats and prolonged T-wave, Q-T interval and two R-waves interval duration in ECG so that leading to a bradycardic effect in heart rate. Key words: Nesfatin-1, Respiratory Paremeters, Electrocardiography, Heart rate, intravenous Injection, Lateral Cerebral Ventricule.