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

This study aimed to elucidate changes in respiratory muscles and their mechanism in cardiomyopathy. The contractile properties and histology of the diaphragm, as well as serum levels of insulin-like growth factor (IGF)-1, were examined in 10 hamsters with idiopathic dilated cardiomyopathy (CM) and 10 controls. At 28 weeks, body weight in CM was reduced compared with controls (114+/-10 versus 144+/-14 g, p<0.0001). The ratio of diaphragm to body weight was significantly higher in CM than in controls (0.228+/-0.015 versus 0.182+/-0.017, p<0.0001). In vitro, maximal diaphragmatic twitch (303+/-63 versus 455+/-119 g x cm(-2)) and tetanic tensions (1,555+/-369 versus 2,204+/-506 g x cm(-2)) were significantly lower in CM than in controls (p<0.005). The half-relaxation time was significantly shorter in CM (19+/-1 ms) than in controls (24+/-3 ms, p<0.0005). Fatiguability at 25 Hz was significantly less in CM (28%) than in controls (42%, p<0.0001). Diaphragm and gastrocnemius adenosine triphosphatase staining showed type I fibre atrophy in CM, associated with an increase in the number of type I fibres in the diaphragm. Histological examination of both muscles revealed an abnormal muscular pattern. Finally, serum levels of IGF-1 were 47% lower in the CM group than in controls (p<0.0001) and were clearly related to the changes in the contractile properties and histology of the diaphragm. In conclusion, cardiomyopathy in hamsters: 1) depressed the force-generating capacity and shortened the relaxation of the hamster diaphragm; 2) induced type I fibre atrophy in combination with a myopathic pattern; and 3) was associated with a significant reduction in serum levels of insulin-like growth factor-1, related to the diaphragmatic changes. Whether these changes are primary myopathic or secondary to heart failure remains to be elucidated.
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PMID:Effects of dilated cardiomyopathy on the diaphragm in the Syrian hamster. 1006 87

Whether the lusitropic potential of short-term exercise in aged rats is linked to an augmentation in the growth hormone/insulin-like growth factor-1 (GH/IGF-1) axis and an alteration in the cardiac renin angiotensin system (RAS) is unknown. Old (28-month-old) male, Fischer 344xBrown Norway rats were randomized to 4 weeks of GH supplementation (300 microg subcutaneous, twice daily) or 4 weeks of treadmill running, or were used as sedentary controls. Six-month-old rats, sedentary or exercised, were used as young controls. Training improved exercise capacity in old animals. Exercise and GH attenuated age-related declines in myocardial relaxation despite an exercise-induced suppression of IGF-1. The regulatory protein, sarcoplasmic Ca2+ adenosine triphosphatase (SERCA2), increased with exercise but not GH. Among aged rats, the cardiac RAS was not altered by training or GH. Thus, the signaling pathway underlying the lusitropic benefit of short-term habitual exercise in the aged rat may be distinct from GH-mediated benefits and independent of the cardiac RAS.
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PMID:Effects of short-term treadmill exercise training or growth hormone supplementation on diastolic function and exercise tolerance in old rats. 1884 Jul 95