TY - JOUR
T1 - Effects of long-term pressure overload on regional myocardial glucose and free fatty acid uptake in rats
T2 - A quantitative autoradiographic study
AU - Kagaya, Yutaka
AU - Kanno, Yuka
AU - Takeyama, Daiya
AU - Ishide, Nobumasa
AU - Maruyama, Yukio
AU - Takahashi, Toshihiro
AU - Ido, Tatsuo
AU - Takishima, Tamotsu
N1 - Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 1990
Y1 - 1990
N2 - To investigate the effects of long-term pressure overload on regional myocardial substrate use, we performed quantitative autoradiography using 2 -deoxy-D-[U-14C]glucose (14C-DG) and β-methyl[1-14C]heptadecanoic acid (14C-BMHDA) in conscious rats with a 10-week ascending aortic constriction. Heart weight/body weight ratio increased by 27% in aortic-constricted rats as compared with sham-operated rats (p<0.01). Myocardial 14C-DG uptake increased (258±63 vs. 144±41 nCi/g, p<0.01, n=6 for each group); however, 14C-BMHDA extraction decreased (251±69 vs. 342±75 nCi/g, p<0.05, n=7 for each group) in aortic-constricted rats as compared with sham-operated rats. In sham-operated rats, both 14C-DG and 14C-BMHDA uptakes were higher in the left ventricular anterior and lateral walls as compared with the posterior wall or the interventricular septum. In aortic-constricted rats, 14C-DG uptake also increased in the interventricular septum, as well as in the left ventricular anterior and lateral walls, as compared with the posterior wall. There was, however, no regional difference in 14C-BMHDA extraction among these four regions. Myocardial blood flow distribution determined by 4-[N-methyl-14C]iodoantipyrine or myocyte width showed no regional variations among the four regions, either in aortic-constricted or sham-operated rats. Regional interstitial fibrosis was small in either group. The present study suggests that myocardial substrate uptake is altered nonhomogeneously, and that the nonhomogeneity is not because of regional variations in blood flow distribution, myocyte hypertrophy, or interstitial fibrosis. The results of angiotensin II-induced acute pressure overloading in other sham-operated rats, in which a remarkable increase in myocardial 14C-BMHDA extraction (n=3, p < 0.01) and no difference in 14C-DG uptake (n=3) as compared with normotensive sham-operated rats were elicited, suggest that the findings in aortic-constricted rats are not direct responses to increased left ventricular pressure itself but rather should be explained by still unknown factors related to prolonged pressure overload.
AB - To investigate the effects of long-term pressure overload on regional myocardial substrate use, we performed quantitative autoradiography using 2 -deoxy-D-[U-14C]glucose (14C-DG) and β-methyl[1-14C]heptadecanoic acid (14C-BMHDA) in conscious rats with a 10-week ascending aortic constriction. Heart weight/body weight ratio increased by 27% in aortic-constricted rats as compared with sham-operated rats (p<0.01). Myocardial 14C-DG uptake increased (258±63 vs. 144±41 nCi/g, p<0.01, n=6 for each group); however, 14C-BMHDA extraction decreased (251±69 vs. 342±75 nCi/g, p<0.05, n=7 for each group) in aortic-constricted rats as compared with sham-operated rats. In sham-operated rats, both 14C-DG and 14C-BMHDA uptakes were higher in the left ventricular anterior and lateral walls as compared with the posterior wall or the interventricular septum. In aortic-constricted rats, 14C-DG uptake also increased in the interventricular septum, as well as in the left ventricular anterior and lateral walls, as compared with the posterior wall. There was, however, no regional difference in 14C-BMHDA extraction among these four regions. Myocardial blood flow distribution determined by 4-[N-methyl-14C]iodoantipyrine or myocyte width showed no regional variations among the four regions, either in aortic-constricted or sham-operated rats. Regional interstitial fibrosis was small in either group. The present study suggests that myocardial substrate uptake is altered nonhomogeneously, and that the nonhomogeneity is not because of regional variations in blood flow distribution, myocyte hypertrophy, or interstitial fibrosis. The results of angiotensin II-induced acute pressure overloading in other sham-operated rats, in which a remarkable increase in myocardial 14C-BMHDA extraction (n=3, p < 0.01) and no difference in 14C-DG uptake (n=3) as compared with normotensive sham-operated rats were elicited, suggest that the findings in aortic-constricted rats are not direct responses to increased left ventricular pressure itself but rather should be explained by still unknown factors related to prolonged pressure overload.
KW - Cardiac hypertrophy
KW - Myocardial free fatty acid metabolism
KW - Myocardial glucose metabolism
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U2 - 10.1161/01.CIR.81.4.1353
DO - 10.1161/01.CIR.81.4.1353
M3 - Article
C2 - 2180593
AN - SCOPUS:0025342650
VL - 81
SP - 1353
EP - 1361
JO - Circulation
JF - Circulation
SN - 0009-7322
IS - 4
ER -