Effects of macrophage migration inhibitory factor on glucocorticoid release and glucocorticoid receptor in rats / 中华麻醉学杂志

ABSTRACT

Objective To investigate the effects of macmphage migration inhibitory factor (MIF) on glucocorticoid (GC) re]ease and glucocorticoid recer (GR) in mts.Methods Test Ⅰ Thirty-two male SD rats weighing 250-300 g were randomly divided into 4 groups(n=8 each)control group(C),low dose recombinant MIF (rMIF) group (rMIF-L),middle dose rMIF group (rMIF-M) and high dose rMIF group (rMIF-H).The animals received l ml normal saline via the right femoral vein in group C.The animals received rMIF50.100 and 200 ng in l ml normal saline though right femoral vein in group rMIF-L,rMIF-M or rMIF-H respectively.Blood samples were taken from left femoral artery immediately before inection(T0,baseline),and at 5 min,3 h,6 h.12 h and 24 h after injection of rMIF(T1-5) for determination of serum concentration of corticosterone.Test Ⅱ Primary cultured neonate rat(2-3 days)myocardial ceils were randomly divided into 3 groups(n=24 each)group C,group rMIF-L and group rMIF-M.The ceUs in group C,rMIF-L and rMIF-M wefe incubated with DMEM.rMIF 50 ng+DMEM and rMIF 100 ng+DMEM for 3 h respectively.The expression of GR and HsPg0 wag determined by Western blot.ResuBs Test Ⅰ The serum concentration of corticosterone was signifieemily higher in the other 3 groups than in group C at T1-5(P<0.05).The sertlm concentration of corticostemne was significantly increased at T1-5 in group rMIF-L,rMIF-M and rMIF-H compared with the baseline values(P<0.05).Test Ⅱ HSP90 expresion was significantly lower in the other two groups than in group C(P<0.05).Them was rio signifieanf difference in HSP90 expression between group rMIF-L and group rMIF-M(P>0.05).There was no significant difference in GR expression among the 3 groups ( P > 0.05). Conclusion MIF druing sepsis can weaken GR function through down-regulating HSP9O expression, resulting in CC resistance.