Accession Number:

ADA277272

Title:

The Effects of Ricin on the Heart and Coronary Arteries

Descriptive Note:

Interim rept. 11 Jan 1993-10 Jan 1994

Corporate Author:

OKLAHOMA UNIV HEALTH SCIENCES CENTER OKLAHOMA CITY

Personal Author(s):

Report Date:

1994-01-20

Pagination or Media Count:

69.0

Abstract:

The effects of giving rabbits a minimal lethal dose 0.22 ugkg of ricin on their hearts and coronary arteries were investigated. Ricin did not alter the time to peak tension of the papillary muscle and its contraction duration, or frequency responses. The EC50 for force development of the papillary muscle in the presence of Bay K 8644 was increased by ricin. Ricin did not alter the resting membrane potential, action potential amplitude, action potential duration, overshoot potential, the effective refractory period, or the maximal dvdt of Phase 0 of papillary muscle but increased monoamine oxidase activity of papillary muscle. The number and affinity of beta receptors and oxygen consumption in the heart were not altered. Ricin did not alter heart rate, P-R interval, or QRS duration of the ECG, but decreased compliance of the isolated heart. Neither isoproterenol- nor phenylephrine-stimulated left ventricular developed pressure, dpdt or -dpdt were changed. Ricin increased the EC50 for contractions of coronary artery to serotonin and histamine with or without endothelium present. It decreased the EC50 for relaxations of the coronary artery to norepinephrine, but not acetylcholine. Thus, ricin alters coronary artery function, and reduces diastolic and systolic function of the heart. Ricin, Ricin in the heart, Ricin in coronary arteries, Ricin on blood vessels, Heart, BL2, BD, RA IV, Lab animals

Subject Categories:

  • Biochemistry
  • Anatomy and Physiology

Distribution Statement:

APPROVED FOR PUBLIC RELEASE