Establishment of a strain of the rat with spontaneously occurring hypertrophic cardiomyopathy

Research Project

Project/Area Number	62580034
Research Category	Grant-in-Aid for General Scientific Research (C)
Allocation Type	Single-year Grants
Research Field	Laboratory animal science
Research Institution	Kyoto Prefectural University of Medicine
Principal Investigator	KURIBAYASHI Toshiro 2nd Dept. Anat., Kyoto Pref. Univ. Med., 医学部, 助手 (80186519)
Project Period (FY)	1987 – 1988
Project Status	Completed (Fiscal Year 1988)
Budget Amount *help	¥1,800,000 (Direct Cost: ¥1,800,000) Fiscal Year 1988: ¥500,000 (Direct Cost: ¥500,000) Fiscal Year 1987: ¥1,300,000 (Direct Cost: ¥1,300,000)
Keywords	WKY / NCrj rats / Hypertrophic cardiomyopathy / 選択交配 / 常染色体優性遺伝 / 胎仔動脈 / 管低形成 / 異常心の生前診断
Research Abstract	We have reported that myocardial abnormalities quite similar to those of human hypertrophic cardiomyopathy occurs spontaneously in some the rat of WKY/NCrj strain; the rat showed, in the absence of blood pressure elevation, marked cardiac hypertrophy, i.e., greater heart weight and a disproportionately thicker ventricular septum in relation to left ventricular free wall than did rats with normal hearts; furthermore, these rats with a marked cardiac hypertrophy had a marked abnormal arrangement of cardiac muscle fibers and myofibrils, a narrowing of the left ventricular cavity, myocardial fibrosis, and mural arteries with an abnormal wall thickening (Jpn Circ J 51: 573-588, 1987). The purpose of the present project is to establish a strain of rats with a higher incidence of marked cardiac hypertrophy, which shoud be a useful animal model for the study of the human disease. Electrocardiographic recordings revealed that a high QRS complex, an axis deviation of the QRS, and a high T wave are characteristic of the with a marked cardiac hypertrophy. On the basis of these findings, selective breeding of rats with a marked cardiac hypertophy and of rats with a normal heart as the control is now being continued. However, the establishment of these strains may require a long process of selection, since there is an evidence that the underlying gene abnormality has already spread widely in this strain; i.e., the WKY/NCrj strain is an established inbred one persisting for more than 30 generations and quite identical abnormalities of the heart occur in the strain of rats from which the WKY/NCrj diverged.