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

Venous plasma and urine amino acids and urea were measured in ten well-trained men, aged 23--45 years, in connection with a 70 km cross-country ski race, lasting 4.39--6.04 h, leading to slight dehydration. The estimated urea production rate during the race was of the order 7.6 mumol/min, kg b.wt, i.e. twice the rate for such men on ordinary protein intake, during ordinary activity, thus suggesting increased protein catabolism. The race led to a fall of the total plasma amino acid concentration to about 60% of the pre-race level. In particular, the branched chain amino acids (valine, iso-leucine, leucine) and alanine were markedly reduced, whereas the S-containing amino acids (taurine, cystine, methionine) and the aromatic (phenylalanine, tyrosine, trytophan, histidine) and glutamine/glutamate were increased, unchanged or only moderately reduced. It is concluded that prolonged heavy exercise is accompanied by increased protein catabolism and changes in the plasma amino acid concentrations similar to those observed during prolonged starvation, but differing from those seen at heavy exercise of less than 2 h duration or prolonged exercise of moderate intensity.
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PMID:Changes in plasma amino acid distribution and urine amino acids excretion during prolonged heavy exercise. 52 87

Twenty patients with anorexia nervosa and a body weight below 60% of the standard weight were studied. One died of starvation; the others survived. Four patients, including the deceased, had such severe weakness that they could not sit up without support, and another five could sit up only from a lateral position. Serum albumin or hemoglobin levels at the beginning of therapy could not be used for nutritional assessment because of dehydration, while increased blood urea nitrogen was associated with acute illness. The present results together with data from previous studies of fatal anorexia indicate that the risk of mortality may be quite low when body weight is above 60% of the standard. We suggest that gross muscle weakness in addition to body weight for height can be a valuable indicator to assess the criticalness in anorexia nervosa.
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PMID:Assessment of emaciation in relation to threat to life in anorexia nervosa. 801 84

Somatostatin produced in the D-cells of the stomach and the pancreas plays an important role in the carbohydrate metabolism and has been suggested to be involved in the disturbed glucose homeostasis during starvation. We investigated two groups of subjects during severe caloric deficiency. Nine healthy subjects (mean age, 32 years) fasted for 4 days, and the plasma concentration of somatostatin increased greatly, from 11.0 +/- 1.3 pM to 21.7 +/- 2.3 pM (p = 0.001). Intravenous infusion of 50 g glucose after a 60-h fast and oral loading of 50 g glucose after an 80-h fast normalized temporarily the plasma concentration within 45 min and 60 min, respectively. In another group of 12 subjects (mean age, 34 years), who participated in a 90-km cross-country ski race lasting 4.45-6.50 h and who were suspected of being in severely catabolic metabolic state, the plasma concentration of somatostatin increased from 6.1 +/- 0.8 pM to 26.9 +/- 4.7 pM (p < 0.001). Post-race oral feeding of 100 g glucose in seven of the subjects normalized the plasma concentration within 30 min, but the concentration remained increased in the five subjects who had no post-race caloric supply. The results indicate a close relationship between somatostatin and glucose during caloric deficiency in man.
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PMID:The effect of glucose on the plasma concentration of somatostatin during caloric deficiency in man. 810 38

Dendrocoelum lacteum, feeding on active prey, adopted a 'sit and wait strategy' upon starvation. During this time metabolic rate fell by a factor of 0.65. About 80% of the energy made available from the catabolism of tissue was lost as heat with the rest being lost as mucus. P. tenuis, feeding on inactive carrion, adopted a 'search out strategy' upon starvation. Metabolic rate fell during this time but only by a factor of 0.72. About 50% of the energy from catabolism was lost as heat and about 50% as mucus. Hence the locomotory strategies adopted by each species during starvation depended on the mobility of the prey and lead to marked differences in the energy balance of the worms.
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PMID:Locomotory strategies in freshwater triclads and their effects on the energetics of degrowth. 2830 62

Pit-building antlions and wormlions are 2 distantly-related insect species, whose larvae construct pits in loose soil to trap small arthropod prey. This convergent evolution of natural histories has led to additional similarities in their natural history and ecology, and thus, these 2 species encounter similar abiotic stress (such as periodic starvation) in their natural habitat. Here, we measured the cold tolerance of the 2 species and examined whether recent feeding or food deprivation, as well as body composition (body mass and lipid content) and condition (quantified as mass-to-size residuals) affect their cold tolerance. In contrast to other insects, in which food deprivation either enhanced or impaired cold tolerance, prolonged fasting had no effect on the cold tolerance of either species, which had similar cold tolerance. The 2 species differed, however, in how cold tolerance related to body mass and lipid content: although body mass was positively correlated with the wormlion cold tolerance, lipid content was a more reliable predictor of cold tolerance in the antlions. Cold tolerance also underwent greater change with ontogeny in wormlions than in antlions. We discuss possible reasons for this lack of effect of food deprivation on both species' cold tolerance, such as their high starvation tolerance (being sit-and-wait predators).
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PMID:The effect of fasting and body reserves on cold tolerance in 2 pit-building insect predators. 2949 87

Ticks are obligatorily hematophagous but spend the majority of their lives off host in an unfed state where they must resist starvation between bouts of blood feeding. Survival during these extended off-host periods is critical to the success of these arthropods as vectors of disease; however, little is known about the underlying physiological and molecular mechanisms of starvation tolerance in ticks. We examined the bioenergetic, transcriptomic and behavioural changes of female American dog ticks, Dermacentor variabilis, throughout starvation (up to nine months post-bloodmeal). As starvation progressed, ticks utilized glycogen and lipid, and later protein as energy reserves with proteolysis and autophagy facilitating the mobilization of endogenous nutrients. The metabolic rate of the ticks was expectedly low, but showed a slight increase as starvation progressed possibly reflecting the upregulation of several energetically costly processes such as transcription/translation and/or increases in host-seeking behaviours. Starved ticks had higher activity levels, increased questing behaviour and augmented expression of genes related to chemosensing, immunity and salivary gland proteins. The shifts in gene expression and associated behavioural and physiological processes are critical to allowing these parasites to exploit their ecological niche as extreme sit-and-wait parasites. The overall responses of ticks to starvation were similar to other blood-feeding arthropods, but we identified unique responses that could have epidemiological and ecological significance for ticks as ectoparasites that must be tolerant of sporadic feeding.
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PMID:Progressive behavioural, physiological and transcriptomic shifts over the course of prolonged starvation in ticks. 3044 39

Ticks are simultaneously fascinating and disgusting. Anyone who has removed a bloated blood-filled tick from themselves or a pet understands the "yuck" factor they arouse. But ticks are also fascinating from a physiological perspective. Ticks are the ultimate sit-and-wait predators. Female ixodid ticks (hard ticks) consume a single meal during each life stage (larva, nymph and adult), which means only three lifetime meals over a 1- to 3-year lifespan. Most males do not feed as adults, so they only feed twice. Thus, prolonged starvation is a quintessential aspect of tick life history. Although ticks have been widely studied for their importance as disease vectors, the vast majority of research has focused on tick-host interactions. Ixodid ticks spend the overwhelming majority of their lives off their hosts, but little is known about these periods. A new study begins to fill in some of these knowledge gaps. In this issue of Molecular Ecology, Rosendale, Dunlevy, Marshall, and Benoit examine physiological, behavioural and transcriptomic changes occurring during long-term starvation of the American dog tick, Dermacentor variabilis. Their work provides insights into how ticks are able to go so long between meals and how they prepare for their next meal.
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PMID:When Do We Eat? The Clock is Ticking. 3067 43