Contractility of isolated cardiac muscle obtained from normotensive and treated or untreated hypertensive rat hearts : effects of inotropic agents

• Main Author: Amanam, Mary Bassey
• Format: Others
• Published: Scholarly Commons 1982
• Subjects: Hypertension; Myocardium; Heart Diseases; Chemotherapy; Rats; Medicine and Health Sciences; Pharmacy and Pharmaceutical Sciences
• Online Access: https://scholarlycommons.pacific.edu/uop_etds/459; https://scholarlycommons.pacific.edu/cgi/viewcontent.cgi?article=1458&context=uop_etds

In the present study, the contractility of isolated cardiac muscle obtained from normotensive and treated or untreated hypertensive rat hearts were investigated. The effects of inotropic agents were also explored • Some SHRs were subjected to chronic antihypertensive treatment. After their blood pressure had been lowered, positive and negative inotropic agents were used to study the papillary muscles. The effects of acidosis, increased extracellular calcium, hypoxia, and reoxygenation on the isolated papillary muscles obtained from their hearts were studied. The same was done for isolated cardiac muscles that were removed from WKYs and SHRs. Isoproterenol in the absence or presence of propranolol was also used to investigate the contractility of SHRs and WKYs. Clonidine, alpha-methyldopa, and verapamil all reduced the blood pressures of SHRs which were on chronic antihypertensive therapy. When propranolol was added to the muscle bath, the developed tension of the SHRs was significantly higher than that of the WKYs by 13.1% (p