Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:Q9UIJ5 (Rec)
 58,342 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The role of stretch and/or tension in maintaining the structural integrity of the myocardial cell was investigated in 16 cats. Right ventricular papillary muscles were studied 1-28 days after transection of the chordae tendinae and compared to adjacent intact papillary muscles. A progressive atrophy, as shown by decreased mean cell cross-sectional area, occurred; by the 28th day mean cardiocyte area was only 28% of the control value. The earliest ultrastructural changes (one day after surgery) were primarily focal and included disorientation of contractile filaments and loss of Z-line substance. During the first week, vacuolation, loss of contractile filaments and infiltration of macrophages and fibroblasts were characteristic. By the second week a massive loss of contractile substance, disappearance of the sarcoplasmic reticulum, and a marked increase in connective tissue occurred. Leptomere structures, membrane alterations, and phagocytosis were the most typical changes between the second and fourth week. Hydroxyproline assays on papillary muscles unloaded for three days showed a 38% increase in connective tissue, indicating an early increase in connective tissue/muscle mass associated with mechanical unloading. It is concluded that the cardiocyte is extremely dependent upon mechanical loading, i.e., stretch and/or tension. Mechanical unloading (tenotomy) results in rapid and marked cellular degeneration which exceeds that observed in skeletal muscle following either disuse or denervation.
Anat Rec 1981 Jul
PMID:Morphological changes in the mechanically unloaded myocardial cell. 727 Sep 27

A relationship between compromised muscles and other tissues has been demonstrated in mdx mouse, an animal model studied for understanding of Duchenne muscular dystrophy. The hypothesis is that changes in the calcaneal tendon of mdx mice occur previous to the onset of rigorous and most marked episodes of muscle degeneration, which start suddenly after 21 days of life. Thus, this study aimed to identify possible alterations in the calcaneal tendon of mdx mouse at 21 days of age. Control and mdx tendons were submitted to mechanical tensile testing, quantification of hydroxyproline, and staining with toluidine blue and picrosirius red. Hydroxyproline content was similar between mdx and control groups. The control tendon presented higher mechanical strength (load, stress, and elastic modulus) and its morphological analysis showed a larger number of round fibroblasts, nuclei with well-decondensed chromatin, and slightly metachromatic well-stained cytoplasmic material, different from that observed in mdx tendons. The results suggest that the absence of dystrophin in mdx mouse can provoke directly or indirectly alterations in the mechanical properties and morphology of the calcaneal tendon.
Anat Rec (Hoboken) 2013 Oct
PMID:Mechanical and morphological aspects of the calcaneal tendon of mdx mice at 21 days of age. 2393 6