Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P20020 (adenosine triphosphatase)
 3,299 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In anesthetized rats, injection of the beta 2-adrenoceptor (beta 2-AR) agonist clenbuterol (0.45 mumol/kg) caused a marked stimulation of 86RbCl (Rb) uptake by skeletal muscle, but had no effect on other tissues; soleus muscle showed the largest (144% increase) response. Injection of another beta 2-AR agonist (salbutamol 0.45 mumol/kg) had no effect on Rb uptake by any tissue except soleus muscle (83%). Both agonists increased body (colonic) temperature to the same extent. A 3-day treatment with salbutamol as a dietary admixture had no effect on body weight, muscle mass, or tissue Rb uptake, whereas the same treatment using clenbuterol produced significant increases in body weight and muscle mass and significant decreases in Rb uptake in three of the four muscle groups studied; Rb uptake in soleus was not affected. In another experiment, the short-term effect of clenbuterol injection on muscle Rb uptake was found to be resistant to a high dose (20 mg/kg) of the selective beta 2-AR antagonist ICI 118551. It was concluded that the selective effects of short-term administration of clenbuterol on muscle Rb uptake, coupled with its effects over 3 days on Rb uptake and muscle hypertrophy, implicate beta-AR modulation of cation transport (possibly via Na,K-adenosine triphosphatase [ATPase] activity) in the anabolic effects of clenbuterol on muscle protein deposition. Since the stimulation of Rb uptake by clenbuterol was resistant to high doses of a selective beta 2-AR antagonist and since salbutamol had little or no effect on muscle hypertrophy or Rb uptake, it is suggested that clenbuterol may exert its effects via an atypical beta-AR.
 ...
PMID:Effects of clenbuterol and salbutamol on tissue rubidium uptake in vivo. 785 56

The possible involvement of increased cation exchange in the anabolic response to the beta 2-selective adrenergic agonist clenbuterol was investigated using dietary admixtures of clenbuterol and the Na,K-adenosine triphosphatase (ATPase) inhibitor digoxin. In a rat feeding trial to assess the effects on body composition, it was found that the higher of two levels (5 and 30 mg/kg diet) of digoxin had an inhibitory effect on the repartitioning effects (ie, increased body weight and fat-free mass) of clenbuterol (2 mg/kg diet). In two further experiments using 30 and 60 mg digoxin/kg diet, it was found that the anabolic effects of clenbuterol on gastrocnemius muscle protein deposition were inhibited by digoxin, but the effects of clenbuterol on soleus muscle protein were more resistant to inhibition. Given the observed dose-dependent inhibition by digoxin of gastrocnemius muscle protein deposition in the three experiments, it was concluded that at least part of clenbuterol's anabolic actions on skeletal muscle may depend on increased Na,K-ATPase activity. However, different mechanisms or a different time course of Na,K-ATPase activation may occur in different muscle fiber types.
 ...
PMID:Effects of digoxin on the anabolic response to clenbuterol. 805 52

Age-related sarcopenia is characterized by decreased muscle mass and muscle strength, and increased muscle fatigability. A decrease in synthesis rates of mixed muscle proteins (average of all muscle proteins), myosin heavy chain (responsible for adenosine triphosphatase action) and mitochondrial proteins (site of adenosine triphosphate production) have been described with aging. Most of these changes start by middle age, thus contributing to the progressive decline in muscle size and function. How closely these changes are related to lifestyle and the decline in several hormones, particularly growth hormone, insulin-like growth factor-I, testosterone and dehydroepiandrosterone, remains to be clearly defined. The ability to measure the specific effects of different types of exercise training on muscle protein metabolism has only recently become available. Thus, future investigations will continue to improve our understanding of protein metabolism in aging skeletal muscles. The development and assessment of successful countermeasures to age-related sarcopenia will hopefully follow these discoveries.
 ...
PMID:Mechanisms of sarcopenia of aging. 1044 78

The effect of exposure to sublethal concentrations of the organophosphate pesticide, quinalphos (1.12, 0.22 mg/l) on biochemical parameters of muscle and enzyme activities in brain, liver and kidney of the Indian major carp, Labeo rohita was studied after 15, 30 and 45 days. The muscle protein and RNA levels decreased whereas DNA levels and acid phosphatase were elevated. Similarly, alkaline phosphatase was depleted. The brain acetyl cholinesterase activity was decreased most (-75.43%) in 1.12 mg/l concentration over a period of 45 days. Lactic dehydrogenase levels in brain and liver were elevated whereas in the kidney they were inhibited. Succinic dehydrogenase and adenosine triphosphatase activities were depleted in brain, liver and kidney. The effects have been discussed for different organ tissues in relation to the pesticide.
 ...
PMID:Chronic toxic effects of quinalphos on some biochemical parameters in Labeo rohita (Ham.). 1071 64