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Assessment of progression and compensatory mechanism of congestive heart failure in cardiomyopathic hamster

山口医学 Volume 40 Issue 1 Page 57-64
published_at 1991-02
Title
心筋症ハムスターにおける慢性心不全の進展ならびに代償機構の解析
Assessment of progression and compensatory mechanism of congestive heart failure in cardiomyopathic hamster
Creators Ryoke Tsutomu
Source Identifiers
For an assessment of progression and compensatory mechanism congestive heart failure in cardiomyopathic Syrian hamster (UM-X7.1), I examined left ventricular (LV) function with echocardiography, LV peak systolic pressure (PSP), plasma renin activity (PRA) and LV myosin heavy chain isozyme in every week of UM-X7.1 (10-35 weeks, n=53) and age matched control hamsters (n=15). A transthoracic echcardiography with 7.5MHz transducer for an assessment of LV function of small animals was developped. LV end-diastolic dimention (LVDd) of UM-X7.1 was proportionally increased with aging until approximately 22 weeks, associated with progressively decreased LV fractional shortening (FS). In UM-X7.1, progressive enlargement of LV dimension and impairment of LV contractility with aging were demonstrated. However, progressive increase in LVDd reached plateau after 22 weeks, suggesting limitation of LV preload reserve at this time. PSP of UM-X7.1 tended to decline from the same week. It was considered that the compensatory mechanism of heart in UM-X7.1 reached limitation at approximately 22 weeks. In metabolic state of myocardium of UM-X7.1, predominant LV myosin isozyme (VM-1) was proportionally decreased with aging and shifted to VM-3 until the late stage. It may be a metabolic compensatory mechanism for improvement of the myocardial efficiency. Furthermore, PRA of UM-X7.1 rised abruptly at approximately the same week as the time of LVDd reaching plateau. The date suggested that the PRA rises after the limitation of compensatory machanism of heart. Therefore the rise of PRA may cause to fall into a vicious cycle of the decompensation of heart failure. The UM-X7.1 is useful model of end-stage of congestive heart failure with some resemblance to human cardiac dysfynction.
Subjects
医学 ( Other)
Languages jpn
Resource Type journal article
Publishers 山口大学医学会
Date Issued 1991-02
File Version Not Applicable (or Unknown)
Access Rights metadata only access
Relations
[ISSN]0513-1731
[NCID]AN00243156
Schools 医学部