title: Sex differences in stretch-dependent effects on tension and Ca(2+) transient of rat trabeculae in monocrotaline pulmonary hypertension.
abstract: We aim to compare the effects of stretch on isometric tension/Ca(2+) transient in the right ventricular trabeculae of control (CONT) and hypertensive (MCT, monocrotaline application) adult male and female rats. The treatment with MCT resulted in RV hypertrophy in males only. Blunted active force-length relation and substantially prolonged twitch were found in MCT-males but not MCT-females (vs same-sex CONT). Ca(2+) transient was prolonged in both MCT-treated groups but extremely so in the MCT-males. The gradual stretch resulted in a distinct "bump" on Ca(2+) transient decline in CONT and MCT-treated groups. The integral magnitude of the "bump" was unaffected by the treatment with MCT in males or females but was larger in males vs females. The rate of "bump" development was significantly slower in MCT-males. In conclusion, the sex-specific differences in the stretch-dependent regulation of [Ca(2+)] i may underlie preservation of the Frank-Starling mechanism in female rat myocardium in monocrotaline-induced pulmonary hypertension.
authors.affiliation: Laboratory of Biological Motility, Institute of Immunology and Physiology, Ural Branch of Russian Academy of Sciences, Yekaterinburg, 620049, Russia, o.lookin@iip.uran.ru.
authors.forename: Oleg
authors.initials: O
authors.lastname: Lookin
authors.forename: Daniil
authors.initials: D
authors.lastname: Kuznetsov
authors.forename: Yuri
authors.initials: Y
authors.lastname: Protsenko
mesh_terms: D000818:Animals; D020013:Calcium Signaling / Q000502:physiology*; D004195:Disease Models, Animal; D004730:Endothelium, Vascular / Q000473:pathology; D005260:Female; D006976:Hypertension, Pulmonary / Q000139:chemically induced / Q000473:pathology / Q000503:physiopathology*; D017380:Hypertrophy, Right Ventricular / Q000139:chemically induced / Q000473:pathology / Q000503:physiopathology; D008297:Male; D016686:Monocrotaline / Q000633:toxicity; D009206:Myocardium / Q000473:pathology; D011667:Pulmonary Veins / Q000473:pathology; D051381:Rats; D017208:Rats, Wistar; D012727:Sex Characteristics
chemical_list: D016686:Monocrotaline