Accession Number : ADA297059

Title :   The Effects of Ricin on the Heart and Coronary Arteries.

Descriptive Note : Final rept.,

Corporate Author : OKLAHOMA UNIV OKLAHOMA CITY COLL OF MEDICINE

Personal Author(s) : Robinson, Casey P.

PDF Url : ADA297059

Report Date : 01 FEB 1995

Pagination or Media Count : 189

Abstract : Effects of ricin on rabbit heart, coronary arteries, and distribution of blood flow to various organs and tissues were investigated. Ricin increased cardiac output, and blood flow to most organs/tissues. Ricin was given 0.22 micrograms/kg and 48 hours later changes were determined. Ricin decreased sensitivities of coronary arteries to 5-HT- and histamine contractions, increased sensitivity to NE relaxations, increased maximal contractions, but did not alter ACh-induced relaxations. Ricin increased basal IP3 levels, but histamine stimulated IP3 levels and basal hydrolysis rates from IP2 to IP1 were depressed. In myocardium, ricin depressed cAMP and cGMP accumulation but not phosphoinositide hydrolysis. Heart rate, bipolar electrocardiograms, action potentials and beta adrenergic receptor number or affinity were not altered. Ricin reduced left ventricular compliance and decreased left ventricular developed pressure per balloon volume.

Descriptors :   *HEART RATE, *RICIN, *CORONARY ARTERIES, OUTPUT, CALCIUM, VOLUME, TISSUES(BIOLOGY), DISTRIBUTION, FACILITIES, ISOLATION, HANDLING, ACCUMULATION, HEART, CYCLIC COMPOUNDS, SENSE ORGANS, BLOOD CIRCULATION, BIPOLAR SYSTEMS, MICROSOMES, ORGANS(ANATOMY), RABBITS, SYMPATHETIC NERVOUS SYSTEM, ELECTROCARDIOGRAPHY, MYOCARDIUM, BALLOONS, HISTAMINE, NUCLEOTIDES, CARDIOVASCULAR AGENTS.

Subject Categories : Anatomy and Physiology

Distribution Statement : APPROVED FOR PUBLIC RELEASE