[The protection of heme oxygenase-1 from acute cardiocyte injury in rats].

OBJECTIVE: To observe the protection of Heme oxygenase-1 (HO-1) from lipopolysaccharide (LPS)-induced cardiocyte injury and its mechanism.

METHODS: Cardiocyte was isolated from SD neonate rat and cultured in vitro, and was divided into control group (normal culture), LPS group (with stimulation of 30 micromoL/L LPS for 1 hour), LPS + Hemin group (with same treatment to LPS group after stimulation of 5 micromoL/L Hemin for 1 hour), and LPS + ZnPP group (with same treatment to LPS group after stimulation of 3 micromoL/L ZnPP for 1 hour). The level of lactic-dehydrogenase (LDH), malondialdehyde (MDA), superoxide dismutase (SOD) were measured by thio-barbituric acid and xanthine oxidase techniques. The cell heart rhythm, survival rate and apoptosis rate were examined. The expressions of nuclear factor kappaB (NF-kappaB), HO-1 and tumor necrosis factor-alpha (TNF-alpha) were measured with Western blotting. The HO-1 mRNA was examined by RT-PCR.

RESULTS: The level of LDH and MDA in LPS, LPS + Hemin, and LPS + ZnPP groups were (113 +/- 15), (79 +/- 13), (154 +/- 22) U/L, and (1.88 +/- 0.36), (1.16 +/- 0.32), (2.84 +/- 0.44) mmoL/L respectively, which were all obviously higher than those in control group [(69 +/- 10) U/L, (0.87 +/- 0.25) mmol/L, P < 0.05]. The level of SOD in LPS, PS + Hemin, and LPS + ZnPP groups (17.8 +/- 1.8, 22.5 +/- 2.4, 13.4 +/- 1.5 U/mL, respectively) was all obviously lower than that in control group (24.3 +/- 3.6 U/mL, P < 0.05). The apoptosis rate and heart rhythm were obviously higher and survival rate significantly lower in LPS, LPS + Hemin, and LPS + ZnPP groups than those in control group (P < 0.05). The level of HO-1mRNA in LPS, LPS + Hemin, and LPS + ZnPP groups was higher than that in control group (P < 0.01), among which LPS + Hemin group was the highest. The level of HO-1, TNF-alpha and NF-kappaB in LPS, LPS + Hemin, and LPS + ZnPP groups was higher than those in control group (P < 0.05), among which the level of HO-1 protein in LPS + Hemin group was the highest, the level of TNF-alpha and NF-kappaB in LPS + ZnPP group was highest.

CONCLUSION: LPS can induce cardiocyte injury, which can be inhibited through the anti-inflammatory, anti-oxidant, and anti-apoptosis functions by HO-1.