TY - JOUR
T1 - Dynamic changes in Gα(i-2) levels in rat hearts associated with impaired heart function after myocardial infarction
AU - Shi, B.
AU - Heavner, J. E.
AU - McMahon, K. K.
AU - Spallholz, J. E.
PY - 1995
Y1 - 1995
N2 - The objective of this study was to determine if levels and function of G(s)α and Gα(i-2) in rat hearts change over time following acute myocardial infarction (MI), and if so, whether the changes in G proteins are associated with changes in heart function. As compared with sham-operated controls, the Gα(i-2) level of MI rats did not change at day 1, increased by 64% at day 3 (P < 0.01) and by 55% at day 9 (P < 0.05) accompanied by reduced adenylyl cyclase activity, and returned to control by day 21. By contrast, the G(s)α level did not change at any time. Cardiac function in MI animals was markedly impaired at days 1, 3, and 9 as evidenced by substantial elevation in LVEDP and reduction in maximum rates of pressure development and relaxation, and was partially restored at day 21. Increased Gα(i-2) level in MI rats correlated significantly to severity of impaired cardiac function. The results show a three-phase dynamic pattern in Gα(i-2) level following acute MI: a lag phase, an increased expression phase associated with marked impairment of heart function, and a late phase in which the expression returns to control level accompanied by partially restored cardiac function.
AB - The objective of this study was to determine if levels and function of G(s)α and Gα(i-2) in rat hearts change over time following acute myocardial infarction (MI), and if so, whether the changes in G proteins are associated with changes in heart function. As compared with sham-operated controls, the Gα(i-2) level of MI rats did not change at day 1, increased by 64% at day 3 (P < 0.01) and by 55% at day 9 (P < 0.05) accompanied by reduced adenylyl cyclase activity, and returned to control by day 21. By contrast, the G(s)α level did not change at any time. Cardiac function in MI animals was markedly impaired at days 1, 3, and 9 as evidenced by substantial elevation in LVEDP and reduction in maximum rates of pressure development and relaxation, and was partially restored at day 21. Increased Gα(i-2) level in MI rats correlated significantly to severity of impaired cardiac function. The results show a three-phase dynamic pattern in Gα(i-2) level following acute MI: a lag phase, an increased expression phase associated with marked impairment of heart function, and a late phase in which the expression returns to control level accompanied by partially restored cardiac function.
KW - G proteins
KW - adenylyl cyclase
KW - coronary artery occlusion
KW - heart failure
KW - left ventricular function
UR - http://www.scopus.com/inward/record.url?scp=0029100545&partnerID=8YFLogxK
U2 - 10.1152/ajpheart.1995.269.3.h1073
DO - 10.1152/ajpheart.1995.269.3.h1073
M3 - Article
C2 - 7573504
AN - SCOPUS:0029100545
SN - 0363-6135
VL - 269
SP - H1073-H1079
JO - American Journal of Physiology - Heart and Circulatory Physiology
JF - American Journal of Physiology - Heart and Circulatory Physiology
IS - 3 38-3
ER -