ABSTRACT
PURPOSE: To determine the effects of oral L-glutamine (L-Gln) and the dipeptide l-alanyl-glutamine (L-Ala-Gln) upon the activity of the malate-aspartate shuttle in the rat distal small intestine following ischemia and reperfusion. METHODS: Seventy-two Wistar rats (350-400g), were randomized in 2 groups (n = 36): group S (Sham) and Group T (Treatment) and divided into 12 subgroups (n = 6): A-A6, and B1-B6. The subgroups A1-A3 were subjected to sham procedures at 30 and 60 minutes. Thirty minutes before the study, rats were treated with calcium caseinate, 0.5g/Kg (subgroups A1, A4, B1, B4), L-Gln, 0.5g / kg (subgroups A2, A5, B2 and B5) or L-Ala-Gln, 0.75g/Kg (subgroups A3, A6, B3, B6), administered by gavage. Ischemia was achieved by clamping the mesenteric vessels, delimiting a segment of bowel 5 cm long and 5 cm apart from the ileocecal valve. Samples were collected 30 and 60 minutes after start of the study for real-time PCR assay of malate dehydrogenases (MDH1-2) and aspartate-aminotransferases (GOT1-2) enzymes. RESULTS: Tissue MDH and GOT mRNA expression in intestinal samples from rats preconditioned with either L-Gln or L-Ala-Gln showed no significant differences both during ischemia and early reperfusion. CONCLUSION: Activation of the malate-aspartate shuttle system appears not to be the mechanism of glutamine-mediated elevation of glucose oxidation in rat intestine during ischemia/reperfusion injury.
OBJETIVO: Determinar os efeitos da administração oral de L-glutamina (L-Gln) e do dipeptídeo L-alanil-glutamina (L-Ala-Gln) sobre a atividade do ciclo malato-aspartato no intestino delgado distal de ratos após isquemia/reperfusão. MÉTODOS: Setenta e dois ratos Wistar (350-400g) foram randomizados em 2 grupos (n = 36): T grupo S (Sham) e grupo (Tratamento) e distribuídos em 12 subgrupos (n = 6): A-A6, e B1-B6. Os subgrupos A1-A3 foram submetidos a procedimentos "sham" aos 30 e 60 minutos. Trinta minutos antes do estudo, os ratos foram tratados com caseinato de cálcio, 0,5 g/kg (subgrupos A1, A4, B1 e B4), L-Gln, 0,5 g/kg (subgrupos A2, A5, B2 e B5) ou L-Ala -Gln, 0,75g/kg (subgrupos A3, A6, B3, B6), administrado por gavagem. A isquemia foi obtida por pinçamento dos vasos mesentéricos, delimitando um segmento do intestino cinco centímetros de comprimento e 5 cm da válvula ileocecal. Amostras foram coletadas aos 30-60 minutos para ensaio de PCR em tempo real das enzimas malato desidrogenases (MDH1-2), aspartato-aminotransferase (GOT1-2). RESULTADOS: A expressão de MDH e GOT mRNA nas amostras provenientes do intestino delgado de ratos pré-condicionados com L-Gln ou L-Ala-Gln não apresentou diferenças significativas, tanto durante a isquemia como na fase inicial de reperfusão. CONCLUSÃO: Ativação do ciclo malato-aspartato não parece ser o mecanismo de elevação glutamina-mediada da oxidação da glicose no intestino de ratos durante a isquemia / reperfusão.
Subject(s)
Animals , Rats , Aspartic Acid/metabolism , Glutamine/pharmacology , Intestine, Small/blood supply , Malates/metabolism , RNA, Messenger/blood , Reperfusion Injury/prevention & control , Aspartate Aminotransferases/blood , Aspartate Aminotransferases/genetics , Disease Models, Animal , Dipeptides/pharmacology , Intestine, Small/enzymology , Malate Dehydrogenase/blood , Malate Dehydrogenase/genetics , Random Allocation , Rats, Wistar , Real-Time Polymerase Chain Reaction , Reperfusion Injury/enzymology , Time FactorsABSTRACT
Serum MDH levels were estimated in 29 consecutive patients of portal hypertension with the objective of ascertaining its diagnostic value as to the cause of portal hypertension and its prognostic significance. Higher levels of serum MDH were found in cirrhotic patients as compared to noncirrhotic ones. There were however no significant differences found in the values when extrahepatic obstruction group was compared with controls. Furthermore, higher MDH activity was found in those patients who died as compared to the surviving ones.
Subject(s)
Humans , Hypertension, Portal/diagnosis , Liver/pathology , Liver Function Tests , Malate Dehydrogenase/blood , PrognosisABSTRACT
Serum zinc and levels of certain zinc containing enzymes like 'lactate dehydrogenase, malate dehydrogenase, alkaline phosphatase and serum insulin were studied in twenty five normal and fifty non insulin dependent diabetics. Zinc estimation was done bp atomic absorption spectrophotometry, insulin by radioimmunoassay and the enzymes by kinetic method. The non insulin dependent diabetic individuals showed significant hypozincaemia (P less than 0.001) associated with significant increase in serum insulin and lactate dehydrogenase level (P less than 0.001). Malate dehydrogenase level was markedly decreased (P less than 0.001). There was no significant variation in serum total proteins, creatinine and alkaline phosphatase levels.