Muscle protein catabolism in the septic patient as measured by 3-methylhistidine excretion
| Autor: | M O'Dell, W R Schiller, William S. Blakemore, J W Geiger, Calvin L. Long, K Henderson |
|---|---|
| Rok vydání: | 1977 |
| Předmět: |
Adult
Male medicine.medical_specialty Fever Nitrogen Medicine (miscellaneous) Muscle Proteins Biology Excretion chemistry.chemical_compound Weight loss Stomach Neoplasms Internal medicine medicine Humans Histidine Colectomy Aged Starvation Diminution Creatinine Nutrition and Dietetics Catabolism Muscles Carcinoma Protein turnover Pharyngeal Neoplasms Middle Aged Methylhistidines Nutrition Disorders Endocrinology chemistry Surgical Procedures Operative Lean body mass Female medicine.symptom |
| Zdroj: | The American journal of clinical nutrition. 30(8) |
| ISSN: | 0002-9165 |
| Popis: | Muscle protein catabolism has been evaluated using the excretion of urinary 3- methylhistidine (3-MEH) in six normal male and six normal female subjects and in four surgical patients, two of whom developed febrile episodes during the course of their study. In addition, their nutritional status was also evaluated using percentage body weight losses before hospital admittance, creatinine-height ratios, and, in two patients, serum alkaline ribonuclease levels. The results indicate that: 1) prolonged starvation may produce decreased 3-MEH excretion because of an adaptive diminution of muscle breakdown in sustained starvation, decreased 3- MEH excretion also may simply reflect diminished lean body mass, 3-MEH excretion may be increased above basal levels because of superimposed stresses such as fever, and the acute phases of starvation produce increased levels of 3-MEH excretion until adaptive mechanisms occur; 2) creatinine-height ratios are low in starvation, and increase not only with improved nutrition but in response to fever and stress of operation, even when these are superimposed on malnutrition; and 3) alkaline RNAase levels are elevated in malnutrition and decrease with improved nutri- tion. The enzyme may also be elevated by the stress of operations. Am. J. Clin. Nutr. 30: 1349-1352, 1977. It has been suggested that muscle protein catabolism may be measured by the urinary excretion of 3-methylhistidine (3-MEH). This compound is present predominantly in muscle protein and has been shown to be synthesized in the intact protein by the methylation of the histidyl residues (1). When muscle protein is catabolized, 3- MEH is not recycled or oxidized in the rat or in man, but is quantitatively excreted in the urine (1 , 2). The urinary excretion of 3- MEH should , therefore , provide a means of measuring the rate of muscle protein break- down. Estimates of whole body protein turnover have suggested ranges up to 300 g of pro- tein/day (3, 4). Daily excretion of 3-MEH allows for the calculation of the contribution of muscle protein breakdown to the total using Asatoor and Armstrong's (5) reported value of 0.027% for 3-MEH concentration in mixed proteins of human calf muscle. |
| Databáze: | OpenAIRE |
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