Adv Exp Med Biol
-
31P NMR technique was applied to monitor changes in the energy metabolism of the brain and heart of unanesthetized cats during shock, stroke, hypoxia and increased functional activity. The results show that in these tissues content of inorganic phosphate, sugar phosphates, phosphocreatine and of ATP can be measured decently in awake animals. At the same time this technique has the great advantage over the disruptive biochemical methods that it gives a semi-continuous reading and it is non-invasive. ⋯ The ATP levels of the brain as it was indicated by 31p NMR spectra were not affected by hemorrhagic shock and stroke which can be attributed probably by the reduced rate of ATP consumption. The verification of this hypothesis needs further work. During increased mechanical performance the levels of SP, and Pi increased, ATP decreased, while CP was not influenced in the heart.
-
The following conclusions can be made on the basis of this work: 1) Measurements of skeletal muscle oxygen tension provide an excellent index of tissue perfusion in haemorrhagic shock. 2) Correction of cardiac output and arterial blood oxygen tension in haemorrhagic shock does not necessarily ensure normal tissue oxygenation. 3) In haemorrhagic shock adequate replacement of blood loss using a balanced salt solution in addition to blood replacement is an integral part of the fluid management. 4) Correction of hypovolemia with an equivalent volume of a plasma expander and subsequent reinfusion of shed blood also returns tissue perfusion to normal. However, this treatment results in marked haemodilution and correction of extracellular fluid loss remains inadequate.
-
Comparative Study
Comparison of the elastolytic effects of human leukocyte elastase and porcine pancreatic elastase.
Porcine and bovine elastins were digested by human leukocyte elastase and porcine pancreatic elastase. The enzymes showed similarities in the extent to which they digested elastin and the pattern and quantitative distribution of N-terminal amino acids in the digests. ⋯ The enzymes also digested tropoelastin differently. The results suggest that leukocyte elastase and pancreatic elastase should not be considered interchangeable in experimental models of tissue injury.