Exogenous apelin changes alpha and beta myosin heavy chain mRNA expression and improves cardiac function in PTU-induced hypothyroid rats.
The most important conditions associated with hypothyroidism is the cardiac dysfunction. Apelin is an endogenous ligand, involved in energy storage and metabolism which improves cardiac contractility. This study was done to evaluate the effects of apelin, l-Thyroxin (T4) or a combination of both, on cardiac function and mRNA expression of two contractile proteins, α and β myosin heavy chain (α-MHC and β-MHC), in 6-propyl-2-thiouracil (PTU)-induced hypothyroid rats. Forty male Wistar rats were randomly assigned into five groups: Ctrl (Control), and 4 hypothyroid groups (H, HA, HT, and HAT). The Hypothyroid (H) group received 0.05% PTU in the drinking water for six weeks; the next 3 groups, along with PTU, received apelin (HA, 200μg/kg/day, ip), T4 (HT, 20μg/kg/day, gavage), or a combination of both drugs (HAT) for the last 2weeks (weeks 5 and 6). TSH and T4 were measured using ELISA kit. Isolated hearts of animals were perfused in Langendorff apparatus and left ventricular developed pressure, cardiac contractility, heart rate, rate pressure product and perfusion pressure were assessed using PowerLab ADInstruments. In addition α-MHC and β-MHC mRNA expression were evaluated by RT-PCR method in heart tissue. Apelin alone or accompanied by T4 significantly increased cardiac contractility and performance as compared to hypothyroid group. Apelin also significantly increased the alpha-MHC mRNA expression and in the presence of T4 significantly decreased beta-MHC mRNA expression. It seems that apelin alone may improve cardiac function in hypothyroid rats via genomic pathways.
Physiology Research Center, Department of Physiology, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran; Endocrine Physiology Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Farzaneh
F
Faraji Shahrivar
Physiology Research Center, Department of Physiology, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran. Electronic address: badavim@yahoo.com.
Mohammad
M
Badavi
Physiology Research Center, Department of Physiology, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
Mahin
M
Dianat
Physiology Research Center, Research Center for Infectious Diseases of Digestive System and Department of Physiology, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
Ali
A
Mard
Physiology Research Center, Department of Physiology, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
Akram
A
Ahangarpour
Health Research Institute, Infectious and Tropical Diseases Research Center, Department of Virology, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
Alireza
A
Samarbaf-Zadeh
D000818:Animals; D000073861:Apelin; D005786:Gene Expression Regulation / Q000187:drug effects*; D007037:Hypothyroidism / Q000139:chemically induced / Q000378:metabolism / Q000503:physiopathology; D036341:Intercellular Signaling Peptides and Proteins / Q000494:pharmacology*; D008297:Male; D009200:Myocardial Contraction / Q000187:drug effects*; D009206:Myocardium / Q000378:metabolism*; D018995:Myosin Heavy Chains / Q000096:biosynthesis*; D011441:Propylthiouracil / Q000009:adverse effects / Q000494:pharmacology; D012333:RNA, Messenger / Q000096:biosynthesis*; D051381:Rats; D017208:Rats, Wistar; D013974:Thyroxine / Q000378:metabolism; D024723:Ventricular Myosins / Q000096:biosynthesis*
D000073861:Apelin; C498579:Apln protein, rat; D036341:Intercellular Signaling Peptides and Proteins; D012333:RNA, Messenger; D011441:Propylthiouracil; D024723:Ventricular Myosins; D018995:Myosin Heavy Chains; D013974:Thyroxine
Apelin; Cardiac function; Hypothyroid; Rat; Thyroxin