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Functional and ultrastructural alterations in experimental diabetic rabbit heart
J Mol Cell Cardiol23
(Supplement
II) (1991)
91 FUNCTIONAL AND ULTHASTRUCTUHALALTERATIONS IN EXPERIMENTAL DIABETIC RABBIT HEART.
'Ihe First Department of Internal T. Ysmaji, T. Fukuhara, K. Mitsunami, M, Kinoshita. Medicine, Shiga University of Medical Science, Ohtsu, Shiga, Japan. The effects of experimental diabetes on cardiac function, ultrastructure and myocardial blood flow (MBF) were studied in rabbits that had been diabetic for 12 and 26 weeks ( 12-D, 26-n ). Diabetic rabbits demonstrated a significant depression in cardiac function (e.g. lower peak +dP/dt) compared with controls ( 12-C, 26-c ), Morphometric analyses in 12 wk but there was no difference between 12-D and 26-D. diabetic rabbits showed the decrease in the volume fraction of myofibrils (Vmyo : 49.3 vs. 59.7 % ) and the increase in the mean cross-sectional area of mitochondria ( A-mit : 0.51 vs. 0.37 pm2 ). In contrast, the damage of wofibrils and mitochondria was less severe in the majority of myocytes at 26 weeks of diabetes ( Vmyo further 53.8 vs. 58.4 %, A-mit : 0.41 vs. 0.40 m2) although myocardium demonstrated deterioration focally. There was no difference in MSF ( measured by H2 clearance method ) between control and diabetic animals even after 26 weeks of diabetes. These results indicate ultrastructural alterations observed at early stage of diabetes were restored partially at later stage and the duration of diabetes did not appear to progressively worsen myocardial function in rabbits.
92
BENEFICIAL EFFECTS OF NIPRADILOL ON CARDlOHYOPA~RIC SYRlAl HAMSTER M.Kato, J.Yang, T.Arino, H.Iwasaki, M.Nagai and M.Nagano Departsent of internal Medicine, Aoto ilospital, Jikei University, Tokyo, Japan. nipradilol is a unique fi -blocker Beta-adrenoceptor blocking agent, In this study 10 of nitroglycerin like vasodilator actions. possesed og/kg of nipradilol was orally administered to J-2-N cardionyopathic
Syrian
hamster
at 5 weeks of age for
10
weeks
(nipradilol
group
n=16).
Age-matched J-2-N hamsters were used as control(untreated group n=lZ). At 15 weeks, electrocardiogram of the hamster of each group was recorded by the limb leads and chest leads. And blood was collected from and CPK, aldolase, malondialdehyde (MDA) of the the abdominal aorta, serum were determined. Wyosin isoenzyme patterns of extirpated myocardiun were compared. Serum CPK, aldolase, MDA were markedly increased in untreated group, whereas these increments were significantly inhibited in the nipradilol group. ECti changes,V? predominance of the ayosin were also much inproved in the nipradilol group. isoenzyae patterns These resuits suggest that nipradilol administration may be beneficial to prevent rayocardial damage developnent of cardiomyopathic hamsters.
93
Expressions and changes Cardiomyopathic Hamster Toshiyuki Hisagazu Departments University
Kudou, Yasuda,
Agiotensinogen
peptide
Hirofumi Sawa, Hideaki Kazuo Nagashima
of Cardiovascular School of Medicine
Medicine
and m-RNA in
Kawaguchi, and Pathology,
Hokkaido
Renin Angiotensinogen system is characterized neuro-hormonal system to maintain homeostasis of the cardiovascular system. Recently some investigator showed existence of the R-A system the heart and its to show expressions
functional importance. This study and changes of angiotensinogen
we designed peptide and
its m-RNA of the heart of the cardiomyopathic hamster. Hearts were taken from age-matched BIO 14.6, BIO 5356, and FlB. Peptide was studied method of immunoperoxidase staining of the tissues, and m-RNA was checked northern blot hybridization and Ribonuclease Protection Assay. s.47
in
(Supplement
II) (1991)
91 FUNCTIONAL AND ULTHASTRUCTUHALALTERATIONS IN EXPERIMENTAL DIABETIC RABBIT HEART.
'Ihe First Department of Internal T. Ysmaji, T. Fukuhara, K. Mitsunami, M, Kinoshita. Medicine, Shiga University of Medical Science, Ohtsu, Shiga, Japan. The effects of experimental diabetes on cardiac function, ultrastructure and myocardial blood flow (MBF) were studied in rabbits that had been diabetic for 12 and 26 weeks ( 12-D, 26-n ). Diabetic rabbits demonstrated a significant depression in cardiac function (e.g. lower peak +dP/dt) compared with controls ( 12-C, 26-c ), Morphometric analyses in 12 wk but there was no difference between 12-D and 26-D. diabetic rabbits showed the decrease in the volume fraction of myofibrils (Vmyo : 49.3 vs. 59.7 % ) and the increase in the mean cross-sectional area of mitochondria ( A-mit : 0.51 vs. 0.37 pm2 ). In contrast, the damage of wofibrils and mitochondria was less severe in the majority of myocytes at 26 weeks of diabetes ( Vmyo further 53.8 vs. 58.4 %, A-mit : 0.41 vs. 0.40 m2) although myocardium demonstrated deterioration focally. There was no difference in MSF ( measured by H2 clearance method ) between control and diabetic animals even after 26 weeks of diabetes. These results indicate ultrastructural alterations observed at early stage of diabetes were restored partially at later stage and the duration of diabetes did not appear to progressively worsen myocardial function in rabbits.
92
BENEFICIAL EFFECTS OF NIPRADILOL ON CARDlOHYOPA~RIC SYRlAl HAMSTER M.Kato, J.Yang, T.Arino, H.Iwasaki, M.Nagai and M.Nagano Departsent of internal Medicine, Aoto ilospital, Jikei University, Tokyo, Japan. nipradilol is a unique fi -blocker Beta-adrenoceptor blocking agent, In this study 10 of nitroglycerin like vasodilator actions. possesed og/kg of nipradilol was orally administered to J-2-N cardionyopathic
Syrian
hamster
at 5 weeks of age for
10
weeks
(nipradilol
group
n=16).
Age-matched J-2-N hamsters were used as control(untreated group n=lZ). At 15 weeks, electrocardiogram of the hamster of each group was recorded by the limb leads and chest leads. And blood was collected from and CPK, aldolase, malondialdehyde (MDA) of the the abdominal aorta, serum were determined. Wyosin isoenzyme patterns of extirpated myocardiun were compared. Serum CPK, aldolase, MDA were markedly increased in untreated group, whereas these increments were significantly inhibited in the nipradilol group. ECti changes,V? predominance of the ayosin were also much inproved in the nipradilol group. isoenzyae patterns These resuits suggest that nipradilol administration may be beneficial to prevent rayocardial damage developnent of cardiomyopathic hamsters.
93
Expressions and changes Cardiomyopathic Hamster Toshiyuki Hisagazu Departments University
Kudou, Yasuda,
Agiotensinogen
peptide
Hirofumi Sawa, Hideaki Kazuo Nagashima
of Cardiovascular School of Medicine
Medicine
and m-RNA in
Kawaguchi, and Pathology,
Hokkaido
Renin Angiotensinogen system is characterized neuro-hormonal system to maintain homeostasis of the cardiovascular system. Recently some investigator showed existence of the R-A system the heart and its to show expressions
functional importance. This study and changes of angiotensinogen
we designed peptide and
its m-RNA of the heart of the cardiomyopathic hamster. Hearts were taken from age-matched BIO 14.6, BIO 5356, and FlB. Peptide was studied method of immunoperoxidase staining of the tissues, and m-RNA was checked northern blot hybridization and Ribonuclease Protection Assay. s.47
in