Abstract
To provide an integrated assessment of changes in systolic and diastolic function in diabetic rats, we measured conscious hemodynamics and performed ex vivo analysis of left ventricular passive-elastic properties. Rats given streptozotocin (STZ) 65 mg/kg i.v. (n = 14) were compared with untreated agematched controls (n = 15) and rats treated with insulin after administration of STZ (H = 11). After 7 d, diabetic rats exhibited decreases in heart rate and peak developed left ventricular (LV) pressure during aortic occlusion. After 26 d of diabetes there were significant decreases in resting LV systolic pressure, developed pressure, and maximal +dP/dt, whereas LV end-diastolic pressure increased and the time constant of LV relaxation was prolonged. The passive LV pressure-volume relationship was progressively shifted away from the pressure axis, and the overall chamber stiffness constant was decreased. However, "operating chamber stiffness" calculated at end-diastolic pressure was increased at 7 d, and unchanged at 26 d. LV cavity/wall volume and end-diastolic volume were increased after 26 d of diabetes. Myocardial stiffness was unchanged at both time intervals. All of the above abnormalities were reversed by the administration of insulin. We conclude that the hemodynamic and passive-elastic changes that occur in diabetic rats represent an early dilated cardiomyopathy which is reversible with insulin.
Original language | English (US) |
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Pages (from-to) | 481-488 |
Number of pages | 8 |
Journal | Journal of Clinical Investigation |
Volume | 86 |
Issue number | 2 |
DOIs | |
State | Published - Aug 1990 |
Keywords
- Diabetes
- Diastole
- Passive-elastic
- Systolic function
- Ventricular relaxation
ASJC Scopus subject areas
- General Medicine