Effects of duration of pressure overload on the reversibility of impaired coronary autoregulation in rats

Fumitoshi Sato, Shogen Isoyama, Tamotsu Takishima

Research output: Contribution to journalArticlepeer-review

4 Citations (Scopus)

Abstract

The aim of this study was to determine the effects of duration of pressure overload on the reversibility of impaired coronary autoregulation in hypertropied hearts. The experiments were performed on 38 anesthetized male Wistar rats aged 6 to 8 weeks. The ascending aorta was banded for 4 or 10 weeks, then in some rats the bands were removed for 4 weeks. We estimated coronary hemodynamics in a model consisting of isolated non-working hearts perfused with Tyrode's solution containing bovine red blood cells and serum albumin. Myocardial mass increased significantly in 4 and 10-week banded groups compared to controls. Four weeks after debanding in 4- and 10-week banded groups, the value returned to that of controls. Autoregulation gain was significantly lower in banded groups than in controls in the range between 50 and 100 mmHg of coronary perfusion pressure. Although the gain normalized in the debanded group after 4 weeks of banding, the value in the debanded groups after 10 weeks of banding remained less than zero between 25 and 150 mmHg of perfusion pressure. In transient flow response to a stepwise increase of perfusion pressure within the autoregulatory range, promptly increased flow was followed by more rapid and greater decrease in controls than in banded groups. The flow response regressed in the debanded group after 4 weeks of banding, while it remained unchanged in the debanded group after 10 weeks of banding. Thus, duration of pressure overload alters the regression of impaired coronary autoregulation in cardiac hypertrophy.

Original languageEnglish
Pages (from-to)131-143
Number of pages13
JournalInternational Journal of Cardiology
Volume37
Issue number2
DOIs
Publication statusPublished - 1992 Nov

Keywords

  • Aortic constriction
  • Coronary circulation
  • Hypertrophy
  • Isolated heart
  • Regression

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine

Fingerprint

Dive into the research topics of 'Effects of duration of pressure overload on the reversibility of impaired coronary autoregulation in rats'. Together they form a unique fingerprint.

Cite this