Abstract
Peak intraventricular pressure and rate of pressure development were lower in hearts from hypophysectomized as compared to normal rats. Treatment of hypophysectomized rats with growth hormone (GH) and thyroxine (T 4) increased heart size, but only T 4 restored hemodynamic function to normal. Ca ++-activated ATPase of myosin from hearts of hypophysectomized rats was reduced as compared to myosin from hearts of normal rats. Treatment of hormone-deficient animals with T 4 restored ATPase to normal, but GH was without effect. K + and NH 4 +-activated ATPase of myosin did not vary with hormonal status of the animals. These findings indicated that hormonal regulation of cardiac contractility involved changes in the catalytic activity of myosin.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Biochemical and Biophysical Research Communications
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
