ABSTRACT
Selected cardiovascular and renal functions were measured for 5 hours in conscious, chair-restrained, female rhesus macaques (Macaca mulatta) after IV (0.05 and 1.0 mg/kg) or oral (1.0 mg/kg) administration of staphylococcal enterotoxin B (SEB). Cardiovascular functions, renal hemodynamics, and renal metabolism were also studied between 6 and 11 hours after IV SEB inoculation. Oral SEB produced few changes in cardiorenal functions. In contrast, IV SEB produced hypotension, tachycardia, increased total peripheral and renal vascular resistance, and decreased cardiac and renal functions. The early significant (P less than 0.05) renal depression was not associated with hypotension (mean arterial blood pressure greater than 100 mm of Hg). However, all measured renal functions except extraction ratio of PAH were positively correlated with decreased blood pressure (r = 0.52 - 0.71) in the later phase of SEB toxemia. It is concluded that the kidney is one of the organs affected by IV SEB. Renal impairment may partially contribute to death during SEB enterotoxemia in macaques.
Subject(s)
Enterotoxins/toxicity , Heart/physiopathology , Kidney/physiopathology , Macaca mulatta , Macaca , Monkey Diseases/physiopathology , Staphylococcus , Animals , Cardiac Output , Enterotoxins/administration & dosage , Female , Haplorhini , Heart Rate , Kidney/blood supply , Kidney Concentrating Ability , Regional Blood FlowABSTRACT
Certain cardiovascular and hepatic functions were measured for a period of 6 to 14 hours in conscious, chaired, male rhesus macaques given (intravenously (IV) or orally) staphylococcal enterotoxin B (SEB). In macaques orally given SEB (1 mg/kg), there was little change in the cardiovascular variables. The half-life of injected indocyanine green was apparently prolonged in macaques given SEB as compared with that in the controls. However, in macaques given SEB (0.05 or 1.0 mg/kg) by IV injection, there were tachycardia, increase in arterial resistance, and decreases in blood pressure, cardiac output, stroke volume, cardiac work, mean cardiac power, and central blood volume. In addition, mean transit time from caudal vena cava to ascending aorta was prolonged and a simultaneous reduction of hepatic removal of indocyanine green occurred.
Subject(s)
Cardiovascular System/physiopathology , Enterotoxins/toxicity , Liver/metabolism , Macaca mulatta , Macaca , Staphylococcus aureus , Administration, Oral , Animals , Blood Pressure , Cardiac Output , Enterotoxins/administration & dosage , Haplorhini , Heart Rate , Indocyanine Green/metabolism , Injections, Intravenous , Male , Monkey Diseases/metabolism , Monkey Diseases/physiopathology , Vascular ResistanceABSTRACT
The effects of virus input multiplicity and of tissue cell concentration upon the growth of Rift Valley fever virus in L cells (Earle) were determined. The titers obtained in suspension cultures with cells obtained from two separate laboratories were significantly different. With both monolayer culture and suspension culture systems, a virus input multiplicity of 2.5 resulted in the greatest proliferation of virus. Optimal viral yields were obtained in suspension cultures containing 4 x 10(5) tissue cells per ml of suspension.
