ADVERSE CARDIOVASCULAR EFFECTS OF OXYTETRACYCLINE PREPARATIONS AND VEHICLES IN INTACT AWAKE CALVES

  • 1 January 1981
    • journal article
    • research article
    • Vol. 42  (8) , 1371-1377
Abstract
Comparisons were made of cardiovascular effects in intact, awake, previously instrumented calves given following oxytetracycline (OXY) preparations and components: polyvinylpyrrolidine vehicle (PVP), OXY HCl in PVP (OXY-PVP), OXY CHl (USP) in saline solution, propylene glycol, 77.8% (PG), propylene glycol vehicle (PGV) and OXY HCl in PGV (OXY-PGV). The 3 preparations containing PG significantly increased pulmonary arterial pressures and significantly decreased cardiac output and stroke volume. Aortic pressures and heart rates significantly decreased. Pulmonic and systemic resistances significantly increased. There were no direct effects measured on left ventricular contractility. Aqueous OXY caused no significant changes. The PVP preparation and vehicle caused no changes in pulmonary pressures, pulmonary resistance, cardiac output or stroke volume. Significant increases were observed in aortic pressure, heart rate and systemic resistance. Left ventricular contractility was not changed. PG-induced changes were a result of histamine release which did not depend on prior sensitization of the calves.