The effects of morphine and remifentanil in isolated rat pherenic nerve-hemidiaphragma muscle [·Izole siçan frenik s?n?r-hemidiyafragma kas preparatlarinda re?ifentan?l ve morf?n?n etk?ler?]
In our study, we aimed to investigate the effect of remifentanil and morphine on neuromuscular junction in isolated rat pherenic nerve-hemidiaphragma muscle preparation. Following approvel the protocol by animal ethic commite of Çukurova University, fourty Wistar rats (220-260 gr.) were killed by decapitation and pherenic nerve-hemidiaphragma muscle (70-80 mg weight) were isolated carefully according to the method described by Kelsen ve Nochomovitz. After the thermoregulation and equilibration period for 60 minutes, the voltage of supramaximal stimulation and optimal muscle strenght were determined by both direct and indirect stimulations. Specimens were divided randomly into two groups before the contraction responses were recorded. After control contraction responses were recorded, morphine (0.1, 1, 10 and 100 µM) in group I (n=20) and remifentanil (0.001, 0.01, 0.1 ve 1 µM) in group II (n=20) were added to the bath solution cumulatively and contraction responses (contraction power: KK), contraction time: KS) and 1/2-relaxation time (YGS) were recorded again. In isolated pherenic nerve-hemidiaphragma muscle, control contraction responses contraction power (KK), contraction time (KS) and elaxation time (YGS) determined by direct and indirect supramaximal stimulations were found similar in morphine and remifentanil group. Contraction responses did not change and were found similar with the cumulative addition of opioids (morphine and remifentanil). It is concluded that remifentanil and morphine did not effect neither presinaptic (indirect) nor postsinaptic (direct) depolarization in isolated pherenic nerve-hemidiaphragma muscle produced any relaxation in neuromuscular junction
