Ornitina α-cetoglutarato na isquemia-reperfusão em membro pélvico de ratos

Abstract

To investigate the effects of the ornitine α-ketoglutarate (OKG) upon metabolites in vivo concentrations in whole blood and gastrocnemic muscle tissue of rats submitted to ischemia-reperfusion of the pelvic limb. Methods - Forty two rats were randomly distributed into three groups: Sham (S), Ischemia (I) and Ischemia-reperfusion (R). These groups were redistributed into subgroups, according to time and to the substance used in the gavage. All animals received via gavage calcium caseinate or OKG as a single dose, ninety minutes before the first laparotomy (L). The subgroup S received only caseinate, whereas subgroups I and R received caseinate or OKG, at the same dose of 5g/kg body weight. Samples were collected at three moments: immediately after L; after 6h with ischemia (ischemia of 6h) or without ischemia; and after 6,5h of L with ischemia-reperfusion (reperfusion of 0,5h) or without ischemia-reperfusion. Data expressed as: mean ± standard deviation, normality test of Korogorov-Smirnov. In case of the results went normalized, the test ANOVA was applied for evaluation significant difference, in case of the results was not normalized, the test of Kurskal-Wallis was used. Significant variations were considered when p <0,05.Results - In S group, at the plasmatic samples, after six hours (6h) or six hours and thirty minutes (6,5h) of L, when compared versus at the moment of L (0h), there was increase of: CPK 6h [141,83 ± 47,88 versus 67,17 ± 21,58 - p <0,004], CPK 6,5h [180,67 ± 70,19 versus 67,17 ± 21,58 - p <0,001]; LDH 6h [248,96 ± 80,62 versus 74,40 ± 33,84 - p <0,001]. In muscular samples there was increase of: lactate 6,5h [3,52 ± 1,27 versus 1,57 ± 0,76 - p <0,008]; there were reductions of: pyruvate 6h [0,035 ± 0,024 versus 0,087 ± 0,041 - p <0,004]. In group I it was observed, for the subgroup submitted to ischemia + caseinate in relation to sham, in plasma, elevations of: CPK [635,17 ± 231,71 versus 141,83 ± 47,88 - p <0,001], DHL [551,16 ± 142,63 versus 248,96 ± 80,62 - p <0,002], pyruvate [0,390 ± 0,069 versus 0,061 ± 0,045 - p <0,001]. In muscle there were elevations of: pyruvate [0,127 ± 0,044 versus 0,035 ± 0,024 - p <0,002], lactate [8,15 ± 0,71 versus 2,73 ± 0,49 - p <0,001] and TBARS [0,012 ± 0,004 versus 0,002 ± 0,001 - p <0,001]. In this same group when comparing subgroup ischemia + OKG versus subgroup sham there were, in the plasma, elevations of: CPK [868,17 ± 308,30 versus 141,83 ± 47,88 - p <0,001], glutathione [19,54 ± 2,08 versus 6,43 ± 1,06 - p <0,001]. In muscle there was elevation of glutathione [101,851 ± 16,457 versus 14,737 ± 0,874 p <0,001]. Still in the I group, it was observed, when subgroup ischemia + OKG was compared to ischemia + caseinate, in the plasma, a decrease of: LDH [296,26 ± 93,62 versus 551,16 ± 142,62 - p <0,004], glucose [104,16 ± 20,81 versus 160,33 ± 27,47 - p <0,001], pyruvate [0,046 ± 0,012 versus 0,390 ± 0,069 - p <0,001] and an elevation of glutathione [19,54 ± 2,08 versus 5,52 ± 0,92 - p <0,001]. In muscle there were decreases of pyruvate [0,047 ± 0,031 versus 0,127 ± 0,045 - p <0,004], lactate [2,47 ± 0,74 versus 8,15 ± 0,71 - p <0,001], TBARS [0,004 ± 0,004 versus 0,012 ± 0,004 - p <0,013]. It was observed elevation of glutathione [101,85 ± 16,45 versus 14,44 ± 2,09 - p <0,001]. In R group, it was observed, when comparing subgroup reperfusion + caseinate versus sham at the plasma, elevations of: CPK [606,33 ± 79,84 versus 180,66 ± 70,19 - p <0,001]. In muscle it was observed elevations of lactate [7,16 ± 2,33 versus 3,52 ± 1,27 - p <0,013] and decrease of G6PDH [0,462±0,22 versus 0,207±0,22 p<0,04]. In R group, when comparing subgroup reperfusion + OKG to subgroup sham, at the plasma, it was evidenced increase of: CPK [558,00 ± 102,83 versus 180,66 ± 70,19 - p <0,001], glucose [232,16 ± 59,76 versus 118,16 ± 24,22 - p <0,001]. In muscle there was observed decrease of G6PDH [0,182±0,22 versus 0,462±0,22]. Still in the group R when comparing the subgroup reperfusion + OKG versus the subgroup reperfusion + caseinate, at the plasma, there were elevations of glucose [232,16 ± 59,76 versus 158,00 ± 24,20 - p <0,013]. In muscle it was noticed a decrease of lactate [3,63 ± 1,16 versus 7,16 ± 2,33 - p <0,008] and elevation of glutathione [63,18 ± 18,98 versus 16,17 ± 1,96 - p <0,001]. Conclusions - Surgical trauma promoted significant alterations in some studied samples. The ischemia-reperfusion model demonstrated to be effective. OKG, as a single dose for gavage demonstrated pro glycolytic aerobic effect. Muscular and systemic protection against muscle cell lesion was also observed as well as an antioxidant effect at the end of ischemia and after ischemia-reperfusion injury.