Effects Of Long-Term Exercise Training On The Iron Storage Of The Rats Liver And Investigations Of Associated Mechanism

Objective To investigate the expression and phosphorylation levels of the rat liver,and study the possible roles of PKC,nitric oxide,SOD and MDA in iron storage of the exercised-rat liver,animal models of exercise training was used in our study.The purpose of our research is to determine the underlying mechanisms of the iron storage of rat liver induced by exercise training.Our researches play an important role in the mechanisms of EILIS as well as offer the reference to dietary iron supplement of players.Methods 40 S-D female rats,3 months old,weighing approximately 110-130g were purchased from the animal center of Jiangsu university were used in this study.Animals were bred in-house in a conventional colony and the environmental conditions controlled at 32～34℃, 55-60%humidity with a 12-h light and dark cycle.Given food (containing iron) and distilled water.Animals were randomly assigned to four groups:sedentary group;exercise group;sedentary group + L-NAME and exercise group + L-NAME(n=10,in each).L-NAME was purchased from Sigma company。The animals in the EG swam in a glass swimming basin filled with water to 50cm width、100cm length and 50cm depth at 32～34℃,5 days per week.The daily training lasted for 30 min in the 1st week and 1 h in the 2nd week.After the training period,2 h of exercise were given per day(9:00-11:00 a.m.),lasting for 3 months.After one week of exercise training,rats in EG2 and SG2 received L-NAME supplementation in their drinking water(1 mg/ml,daily prepared) for 3 months.At three moths after exercise training,changes of the hematological indices of iron status,nitric oxide and induces of lipid peroxidation were investigated.Western blot analysis was performed to detect the alterations of PKC and p-PKC of the rat liver.Results At 3 months after exercise training,Hb、Hct and PI of animals from EG1 significantly decreased compared with that of SG1(p＜0.05), while TS%and TIBC changed slightly;And the hematological indices of iron status of animals from EG2 were reversed markedly after the non-specific NOS inhibitor L-NAME being used.As compared with the corresponding sedentary groups,NHI contents of exercise group was decreased significantly(p＜0.01),activities of TNOS、iNOS were increased greatly as well as NO concentration,SOD increase while MDA decrease;And the indices of the livers of animals from EG2 were reversed markedly after the non-specific NOS inhibitor L-NAME being used.Western blot analysis was performed to detect the alterations of PKC and p-PKC of the rat liver induced by long-term exercise training. At 3 months after exercise training.The expression of PKC was decreased(P＜0.05) while its phosphorylation did not change in SG2 (sedentary group + L-NAME) as compared to that of SG1(sedentary group).In addition,the expression and phosphorylation levels of PKC in animals from EG2(exercise group + L-NAME) was decreased markedly(p＜0.01) compared with that of EG1(exercise group).Conclusions Decreasing of The hematological indices of iron status were found by the animal models,markedly decreased the content of NHI, activities of TNOS,iNOS were increased greatly as well as NO concentration,SOD increase while MDA decrease.After 3 months of exercise training,the phosphorylation of PKC was increased while its expression did not change.The indices of hematological as well as that of the livers of animals from EG2 were reversed markedly after the non-specific NOS inhibitor L-NAME being used.And the results demonstrate that PKC and oxidative stress might be involved in exercise-induced lower iron status mediated by NO.