{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,18]],"date-time":"2026-09-18T10:14:02Z","timestamp":1789726442602,"version":"4.0.1"},"reference-count":0,"publisher":"Ovid Technologies (Wolters Kluwer Health)","issue":"3","content-domain":{"domain":["www.ahajournals.org"],"crossmark-restriction":true},"short-container-title":["Circulation Research"],"published-print":{"date-parts":[[1991,3]]},"abstract":"<jats:p>The mechanisms by which the aged heart adapts to a superimposed pressure load such as hypertension have not been described. We therefore investigated biochemical and molecular genetic adaptations in the 24-month-old rat heart subjected to renovascular hypertension. Compared with 4-month-old rats, aging was associated with a 68% increase in left ventricular mass without any change in heart weight-to-body weight ratio, a 33% reduction in calcium-activated myosin ATPase activity, and a shift from a V1 to a V3 predominant myosin heavy chain (MHC) isoform distribution. A 46% reduction in alpha-MHC mRNA and a reciprocal increase in beta-MHC mRNA was seen. When hypertension was superimposed, there was a further 75% increase in ventricular mass, a 63% increase in heart weight-to-body weight ratio, and a 19% reduction in myosin ATPase. Myosin isozyme distribution was further shifted to V3, and the ratio of alpha-MHC to beta-MHC mRNA was reduced. In addition, with hypertension a significant (greater than 50%) reduction in the mRNA level of the cardiac sarcoplasmic reticular calcium-activated ATPase was seen. These data demonstrate that the aged myocardium is able to respond to a superimposed pressure load with a molecular genetic and protein synthetic pattern of hypertrophy analogous to that seen in younger animals.<\/jats:p>","DOI":"10.1161\/01.res.68.3.645","type":"journal-article","created":{"date-parts":[[2012,6,12]],"date-time":"2012-06-12T00:47:05Z","timestamp":1339462025000},"page":"645-652","update-policy":"https:\/\/doi.org\/10.1161\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":46,"title":["Effect of aging and hypertension on myosin biochemistry and gene expression in the rat heart."],"prefix":"10.1161","volume":"68","author":[{"given":"P","family":"Buttrick","sequence":"first","affiliation":[{"name":"Department of Medicine, Montefiore Medical Center, Bronx, N.Y. 10467."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"A","family":"Malhotra","sequence":"additional","affiliation":[{"name":"Department of Medicine, Montefiore Medical Center, Bronx, N.Y. 10467."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"S","family":"Factor","sequence":"additional","affiliation":[{"name":"Department of Medicine, Montefiore Medical Center, Bronx, N.Y. 10467."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"D","family":"Greenen","sequence":"additional","affiliation":[{"name":"Department of Medicine, Montefiore Medical Center, Bronx, N.Y. 10467."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"L","family":"Leinwand","sequence":"additional","affiliation":[{"name":"Department of Medicine, Montefiore Medical Center, Bronx, N.Y. 10467."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"J","family":"Scheuer","sequence":"additional","affiliation":[{"name":"Department of Medicine, Montefiore Medical Center, Bronx, N.Y. 10467."}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"276","container-title":["Circulation Research"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.ahajournals.org\/doi\/pdf\/10.1161\/01.RES.68.3.645","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2024,5,12]],"date-time":"2024-05-12T20:40:39Z","timestamp":1715546439000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.ahajournals.org\/doi\/10.1161\/01.RES.68.3.645"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1991,3]]},"references-count":0,"journal-issue":{"issue":"3","published-print":{"date-parts":[[1991,3]]}},"alternative-id":["10.1161\/01.RES.68.3.645"],"URL":"https:\/\/doi.org\/10.1161\/01.res.68.3.645","relation":{},"ISSN":["0009-7330","1524-4571"],"issn-type":[{"value":"0009-7330","type":"print"},{"value":"1524-4571","type":"electronic"}],"subject":[],"published":{"date-parts":[[1991,3]]},"assertion":[{"value":"1991-03-01","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}