The Effect of Nitric Oxide on the Rat Diaphragm at Different Frequencies of Indirect Electrical Stimulation

Introduction: Nitric oxide (NO) is a second messenger that regulates neurotransmitter release at the neuromuscular junction (nmj). Evidences accumulate on its potency as a neuro-modulator in CNS, PNS. This work investigates the effect of NO on (nmj) by adding L-arginine known as NO donor. Material and Methods: 30 albino rats’ diaphragms divided into two groups. Both exposed to L-argnine followed by Bovine Hb and stimulated by indirect electrical stimulation. Gp 1 stimulated at 0.5Hz. Gp2 stimulated at 100Hz. The amplitude of maximum contraction (AMC) (ΔY), contraction time (ΔX) and half relaxation time (1⁄2 Rt) measured. Results: In presence of NO Gp1 showed a significant increase in (AMC) (ΔY) and (ΔX) with a significant decrease in (1⁄2 Rt). Gp2 showed a significant increase in (AMC)(ΔY). Conclusion: Nitric oxide (NO) facilitates neuromuscular transmission at presynaptic level. Bovine Hemoglobin reduces Nitric oxide’s induced effects.