Long Term Objective: To understand the nature, sites and mechanisms of how sex hormones regulate cardiac myofilament activity.
Short Term Objectives: The proposed research focuses on:
a. the sites and mechanisms of cardiac myofilament Ca2+ hypersensitivity modified by ovarian sex hormone deprivation.
b. the sites and mechanisms of action of ovarian sex hormones in regulating maximum cardiac myofilament ATPase activity.
c. the significance of male sex hormones in cardiac myofilament Ca2+ activation in hormone-deprived and hormone-overloaded conditions.
The specific objectives for this proposal are:
Aim #1 To determine the adaptive alterations in SR Ca2+ uptake activity in the heart of ovariectomized rats complicated with diabetes.
Aim #2 To determine the significance of cross-bridge kinetics in regulating cardiac myofilament activity in ovariectomized rats complicated with diabetes.
Aim #3 To determine the mechanical contractile properties of cardiac muscle fiber prepared from castrated and high testosterone rats.
Aim #4 To determine the relations of cardiac hypertrophy induced in high plasma testosterone rats to the SR Ca2+ uptake function.
Aim #5 To determine the signaling component, physiologic or pathologic pathway, that involves in testosterone-induced cardiac hypertrophy.
