Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0015672 (fatigue)
 51,768 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Some rodent species show rhythmic bouts of vibrissal protractions and retractions, referred to as whisking, that are among the fastest movements performed by mammals. To better understand the muscular basis of whisking, we compared (1) whisker movements of two whisking species (mouse, rat) and a non-whisking species (guinea pig), (2) the muscle fiber composition of intrinsic whisker muscles of whisking and a non-whisking species, and (3) the muscle fiber composition of intrinsic whisker muscles and of selected skeletal muscles. Using high-speed videography, we found that mice, rats, and guinea pigs can generate fast and large-amplitude whisker movements. Guinea pigs do not show bouts of fast, strictly rhythmic whisker movements, and the average speed of their whisker movements is much lower than in mice and rats. Analysis of mRNA expression of myosin heavy chain isoforms, myofibrillar ATPase staining, and antibody labeling indicate that in all three species intrinsic whisker muscles are composed predominantly of type 2B muscle fibers. Intrinsic whisker muscles of mice consisted of type 2B (> or =90%) and type 2D fibers. In rats we observed, in addition to type 2B/2D fibers, approximately 10% of slow type 1 fibers, and in guinea pigs we observed approximately 3% of slow type 1 fibers and 20% of type 2A fibers. Type 2B fibers have high levels of anaerobic glycolytic enzymes providing a rapid source of ATP and high maximum velocity of contraction but are less fatigue resistant than other muscle fiber types. The high percentage of type 2B fibers distinguishes the intrinsic whisker musculature from skeletal muscles and may have evolved for fast scanning of the sensory environment.
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PMID:Fiber types of the intrinsic whisker muscle and whisking behavior. 1505 18

Rhodiola rosea improves exercise endurance and fatigue. We hypothesized that ingredients in Rhodiola rosea may increase antioxidant capability against swimming induced oxidative stress. In this study, we have identified the Rhodiola rosea ingredients, p-tyrosol, salidroside, rosin, rosavin and rosarin by high performance liquid chromatography-mass spectrometer and evaluated their O2(-)*, H2O2, and HOCl scavenging activities by a chemiluminescence analyzer. We next explored the effect and mechanism of Rhodiola rosea on 90-min swimming-induced oxidative stress in male Wistar rats fed with three doses of Rhodiola rosea extracts in drinking water (5, 25, 125 mg/day/rat) for 4 weeks. Our results showed that the 4 major ingredients (salidroside, rosin, rosavin and rosarin) from Rhodiola rosea extracts scavenged O2(-)*, H2O2, and HOCl activity in a dose-dependent manner. The ninety-min swimming exercise increased the O2(-)* production in the order: liver > skeletal muscle > blood, indicating that liver is the most sensitive target organ. The level of plasma malonedialdehyde, a lipid peroxidation product, was also increased after exercise. Treatment of 4 weeks of Rhodiola rosea extracts significantly inhibited swimming exercise-enhanced O2(-)* production in the blood, liver and skeletal muscle and plasma malonedialdehyde concentration. The expression in Mn-superoxide dismutase Cu/Zn-superoxide dismutase, and catalase in livers were all enhanced after 4 weeks of Rhodiola rosea supplementation especially at the dose of 125 mg/day/rat. Treatment of Rhodiola rosea extracts for 4 weeks significantly increased swimming performance. In conclusion, treatment of Rhodiola rosea extracts for 4 weeks could reduce swimming-enhanced oxidative stress possibly via the reactive oxygen species scavenging capability and the enhancement of the antioxidant defense mechanisms.
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PMID:Attenuation of long-term Rhodiola rosea supplementation on exhaustive swimming-evoked oxidative stress in the rat. 2003 36

To assess the effects of a blockade of central D1- and D2-dopaminergic receptors on metabolic rate, heat balance and running performance, 10 nmol (2 microl) of a solution of the D(1) antagonist SCH-23390 hydrochloride (SCH, n = 6), D2 antagonist eticlopride hydrochloride (Eti, n = 6), or 2 microl of 0.15 M NaCl (SAL, n = 6) was injected intracerebroventricularly into Wistar rats before the animals began graded running until fatigue (starting at 10 m/min, increasing by 1 m/min increment every 3 min until fatigue, 5% inclination). Oxygen consumption and body temperature were recorded at rest, during exercise and following 30 min of recovery. Control experiments with injection of two doses (10 and 20 nmol/rat) of either SCH or Eti solution were carried out in resting rats as well. Body heating rate, heat storage, workload and mechanical efficiency were calculated. Although SCH and Eti treatments did not induce thermal effects in resting animals, they markedly reduced running performance (-83%, SCH; -59% Eti, p < 0.05) and decreased maximal oxygen uptake (-79%, SCH; -45%, Eti, p < 0.05) in running rats. In addition, these treatments induced a higher body heating rate and persistent hyperthermia during the recovery period. Our data demonstrate that the alteration in dopamine transmission induced by the central blockade of dopamine- D1 and D2 receptors impairs running performance by decreasing the tolerance to heat storage. This blockade also impairs the dissipation of exercise-induced heat and metabolic rate recovery during the post-exercise period. Our results provide evidence that central activation of either dopamine- D1 or D2 receptors is essential for heat balance and exercise performance.
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PMID:Effects of blockade of central dopamine D1 and D2 receptors on thermoregulation, metabolic rate and running performance. 2036 Jun 15

The CACNA1F gene encodes a member of the alpha-1F subunit family in the voltage-dependent calcium channel (Cav1.4) complex. Mutations in this gene result in incomplete congenital stationary night blindness (iCSNB2) in humans. And Cav1.4 mutation could affect the functions of the skeletal muscle. This study investigated the role of Cacna1f mutations in alteration of the skeletal muscle functions in a Cacna1f mutation rat model (Cacna1f(CSNB2) rat). We found that the muscle endurance behaviors of Cacna1f(CSNB2) rats were significantly lower than those of the wild-type rats. The high-frequency fatigue resistance of the soleus muscle was decreased in Cacna1f(CSNB2) rats under continuous tetanic stimulation. The expression levels of the syntaxin (SYN) proteins in the soleus of the Cacna1f(CSNB2) rats were lower than those of wild-type rats. SYN was expressed in the soleus muscle, but not in the extensor digitorum longus. The Cav1.4 protein was not detected in the skeletal muscle of Cacna1f(CSNB2) rats. The Cacna1f mRNA level in the soleus of Cacna1f(CSNB2) rats was decreased compared with that in wild-type rats. This study demonstrated for the first time that the Cacna1f mutation reduces the function of slow-twitch skeletal muscle. And it also demonstrated that the Cacna1f gene affects synapse-associated protein expression, which may block the signal transmission in synaptic connectivity of the retina and skeletal muscle in Cacna1f-mutant rats.
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PMID:Cacna1f gene decreased contractility of skeletal muscle in rat model with congenital stationary night blindness. 2574 27