Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0038187 (starvation)
 24,951 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Urinary excretion of the post-translationally modified amino-acid 3-methylhistidine, derived from the contractile proteins actin and myosin, was measured in patients with conditions associated with nitrogen loss. The ratio of 3-methylhistidine:creatinine excretion, a measure of the fractional catabolic rate of myofibrillar protein was increased in severe injury, thyrotoxicosis, neoplastic disease, prednisolone administration, and sometimes Duchenne muscular dystrophy. In myxoedema, osteomalacia, and hypothermia the ratio was decreased; and starvation, elective operations, and rheumatoid arthritis had little effect. Provided that the diet is meat free, measurement of urinary 3-methylhistidine may provide useful information on the cause of protein loss.
 ...
PMID:Clinical usefulness of urinary 3-methylhistidine excretion in indicating muscle protein breakdown. 678 20

Sixteen-week-old control and obese rats survive longer than 8-wk-old control rats. In addition, unlike the 8-wk-old group, they conserve tissue RNA and protein. To evaluate the basis for this, the effects of starvation on circulating fuels and hormones and the urinary excretion of nitrogen and 3-methylhistidine (3MH) were compared in the three groups. Urinary nitrogen and 3MH diminished during prolonged starvation in 16-wk-old obese and control rats, suggesting that both groups are able to conserve protein and curtail muscle proteolysis. In contrast, urine nitrogen and 3MH did not decrease in 8-wk-old control rats. Protein conservation in the older rats was associated with diminished blood levels of alanine and increased levels of lipid fuels, ketone bodies, and free fatty acids. Although ketone bodies and free fatty acids were also increased during the first few days of starvation in 8-wk-old rats, there was no evidence of protein sparing. In all groups, as fat stores became exhausted terminally, blood lipid levels decreased and protein catabolism increased. Starvation caused insulin to decrease to comparable levels in all rats; however, minimal levels were reached later in the older groups. Thyroxine and triiodothyronine (T3) decreased during the fast in both control groups; however, T3 did not decrease in the obese rats. These findings support the contention that the conservation of protein during prolonged starvation requires the continued availability of lipid fuels. The role of insulin and thyroid hormone in modulating these adaptations is unclear.
 ...
PMID:Starvation in the rat. II. Effect of age and obesity on protein sparing and fuel metabolism. 742 20

This study has evaluated the effects of recombinant human insulin-like growth factor I (rhIGF-I) to moderately stressed post-operative patients provided with dextrose as the only exogeneous substrate. Thirty patients who underwent elective colorectal surgery were randomized to receive either rhIGF-I (80 micrograms kg-1 bw) subcutaneously twice daily or placebo injections in a double-blind parallel group design. Nitrogen balance, urinary 3-methyl-histidine excretion plasma growth hormone (GH), serum cortisol, IGF-I binding proteins (IGFBP-1,3), glomerular filtration rate, plasma amino acid concentrations and whole-body energy expenditures were measured as effector variables during days 1-5 post-operatively. Animal and isolated tissue experiments were performed as additional control experiments to confirm cellular effectiveness of the recombinant material. rhIGF-I increased significantly the glomerular filtration rate and prevented the adaptive decrease in whole-body energy expenditure in response to partial starvation in the postoperative period. Serum and plasma concentrations of IGFBP-1,3 cortisol, blood glucose and amino acids were not significantly influenced by rhIGF-I administration, while plasma GH levels decreased significantly as expected. rhIGF-I had no effect on either nitrogen balance or protein breakdown (3-methylhistidine excretion) in post-operative patients on dextrose supplementation only, although plasma concentrations of IGF-I increased from 130-140 ng mL-1 to a range of 300-450 ng mL-1. In contrast, IGF-I stimulated the synthesis of both globular and myofibrillar proteins (+50%, P < 0.01), when given as a single dose (100 micrograms kg-1) 2 h before measurements of protein synthesis in skeletal muscles of overnight fasted adult mice. This stimulatory effect by IGF-I (1 microgram mL-1) was also confirmed by measurements of skeletal muscle protein synthesis in vitro (+40%, P < 0.05). Orally re-fed mice had a normal transcription of IGF-I mRNA in skeletal muscle cells, while overnight fasted mice showed a trend to down-regulated transcription. Our results demonstrate that rhIGF-I has several significant physiological effects, without major side-effects, when supplied to partially starved patients in the post-operative phase. The lack of a whole-body nitrogen sparing effect by rhIGF-I alone to post-operative patients is not clear, but was most likely explained by subnormal plasma concentrations of amino acids.
 ...
PMID:The effect of recombinant human IGF-I on protein metabolism in post-operative patients without nutrition compared to effects in experimental animals. 855 66

Sarcopenia could result from the inability of an older individual to recover muscle lost during catabolic periods. To test this hypothesis, we compared the capacity of 5-day-refed 12- and 24-mo-old rats to recover muscle mass lost after 10 days without food. We measured gastrocnemius and liver protein synthesis with the flooding-dose method and also measured nitrogen balance, 3-methylhistidine excretion, and the gene expression of components of proteolytic pathways in muscle comparing fed, starved, and refed rats at each age. We show that 24-mo-old rats had an altered capacity to recover muscle proteins. Muscle protein synthesis, inhibited during starvation, returned to control values during refeeding in both age groups. The lower recovery in 24-mo-old rats was related to a lack of inhibition of muscle proteolysis during refeeding. The level of gene expression of components of the proteolytic pathways did not account for the variations in muscle proteolysis at both ages. In conclusion, this study highlights the role of muscle proteolysis in the lower recovery of muscle protein mass lost during catabolic periods.
 ...
PMID:Lower recovery of muscle protein lost during starvation in old rats despite a stimulation of protein synthesis. 1051 19


<< Previous 1 2 3