1989 Fiscal Year Final Research Report Summary
Cardiac growth factors and cardiac chalones.
| Project/Area Number |
62570405
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Circulatory organs internal medicine
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| Research Institution | Jikei University School of Medicine |
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Principal Investigator |
NAGANO Makoto Jikei University, School of Medicine, Dpt. Internal Medicine, Professor, MD, 医学部, 教授 (60056497)
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| Co-Investigator(Kenkyū-buntansha) |
TAKAHASHI Kaoru Jikei University, School of Medicine, Lecturer, MD, 医学部, 講師 (40112833)
TAKEDA Nobuakira Jikei University, School of Medicine, MD, Lecturer, 医学部, 講師 (60112835)
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| Project Period (FY) |
1987 – 1989
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| Keywords | heart size / cardiac hypertrophy / cardiac growth factor / cardiac inhibiting factor / cardiac chalone / cardiomyopathic Syrian hamster |
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| Research Abstract |
This study was undertaken to elucidate the presence of cardiac growth factors in the hypertrophied rat heart and of cardiac inhibiting factors (chalones) in the normal rat heart.
The cardiac size can be regulated by the balance between the action of cardiac growth factors and inhibiting factors, chalones. The isolated fraction from hypertrophied rat heart stimulated the cardiac growth of the chicken embryo. This fraction is the substance with an isoelectric point 8.3 and a molecular weight 43 K dalton protein. In our experiment, the isoelectric point 8.3 protein reaches its maximum by the fifth to sixth post-operative week and then gradually decreases. Opposed to this, we examined that the IP 7.1 fraction, which can also be found in the normal heart, decreases around the fourth to sixth week when heart is hypertrophied. This protein inhibited the cardiac growth of the cultured rat myocardial cells.
In our first experiment, the protein of cardiac growth factors could not be identified in the normal rat and in the old SHR hearts. But according to the isoelectric focusing chromatography, it is present to a certain extent. In the young SHR, the 43 kdalton protein can be found although not as much as in the 5-6 weeks Goldblatt hypertensive rat heart, while, in the old SHR, it could not be determined. In the heart of young cardiomyopathic Syrian hamster, in the hypertrophied rat heart induced by aortic constriction, the 43 k dalton protein can be identified.
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