Movement Of Ho-co System In The Sd Rat Aortic Smooth Muscle And Endogenous No And Co In The Movement Interaction

Objective:Recent studies indicate that vascular smooth muscle cells (VSMCs) generate carbon monoxide (CO) from the degradation of heme by the enzyme heme oxygenase-1 (HO-1). The vascular effects of CO resemble those of nitric oxide (NO). In the present study, we investigated the contribution of the heme oxygenase/CO pathway to the regulating vascular tone and cytoprotective effect in exercise.and the relationships between endogenous carbon monoxide and nitric oxide in exercise .Methods:The HO activity,CO formation in rat aortic vascular smooth muscle ,and serum NO content were examined.Results: Compared with the control group, the HO activity in tissues from different workload exercise rats(45min,90min,150min) were all sigmificantly elevated by 53.78%(p<0.01),81.48%(P<0.01)and 120.66%(P<0.01),respectively,after 9-week swimming.Meanwhile ,the CO formation was increased by 31.98%(P<0.01),83.12%(P<0.01),121.90%(P<0.01),respectively.And the increase levels of HO and CO were dependent upon the exercise workload.But the HO activity and CO formation in tissues from the one-time exhausting group didn't changed.The HO activity and CO formation from the NOS inhibited group(L-NAME group) were increased by 33.64%(P<0.05) and 49.83%(P<0.01).As for the exercise plus NOS inhibition group(exercise+L-NAME),HO and CO were augmented by 134.59%(P<0.01)and 115.78%(P<0.01).And interestedly , the HO and CO from exercise+L-NAME group were increased by 75.52%(P<0.01) and 44.01%(P<0.01),compared with that of the L-NAME group.Conclusion: ( 1 ) Long-term exercise may activate the HO-CO system.and subsequently regulate the tone of the vascular smooth muscle via cGMP pathway,inhibite the proliferation of VSMCs and the adhesion of platelet.(2)The induction of HO-CO system via exercise is dependent upon the workload of theexercise.(3)The endogenous HO-CO system was upregulated more by long-term exercise to relax the VSMC during the damage of NOS/NO system.(4) The NOS/NO and HO/CO systems might act each other during the regulating the vascular tone.