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The Langendorff Heart
Published in John H. McNeill, Measurement of Cardiac Function, 2020
The Langendorff heart preparation is one of the earliest models of an isolated organ, used by physiologists and pharmacologists to investigate function and the effect of different agents on an isolated tissue. This preparation was first described by O. Langendorff in 1895.1 The procedure is based on perfusing an isolated heart through the aorta (retrograde) with an oxygenated physiological buffer. The resulting retrograde perfusion pressure closes the aortic valve, facilitating the perfusion of the coronary blood vessels located at the base of the aorta. As the heart is a highly vascularized organ, the physiological buffer eventually gains access to all cells within the heart. Since the heart requires a steady supply of oxygen and metabolic energy for its normal functioning, it is crucial to rapidly extract the organ from the chest cavity without an episode of ischemia, prevent occlusion of the coronary arteries with blood clots, and rapidly supply the organ with a highly oxygenated physiological buffer.
Cardiovascular and hemodynamic consequences of recombinant placental growth factor administration in Guinea pigs
Published in Hypertension in Pregnancy, 2022
Adelene Y. Tan, Ken Kearney, Courtney Jenkins, S. Ananth Karumanchi, Walter Bee, Paul Kussie
Consistent with previous studies, recombinant PlGF infusions acutely reduced blood pressure in Guinea pigs; the BP reduction occurred within minutes and lasted from 14 to over 24 hours depending on the dose. A compensatory increase in HR followed the blood pressure change, suggesting a baroreflex response. To rule out any direct effect on the heart, the ex vivo Langendorff heart preparation was used and found no cardiac changes. Together these results suggest that the PlGF activity is restricted to blood vessels. In the Langendorff heart preparation, the increase in perfusion flow following administration of PlGF is evidence of dilation of the coronary arteries. There was no dose-dependency across groups, indicating a saturable pharmacodynamic response. There were no other functional changes associated with the increase in perfusion flow. Additional studies with lower doses of PlGF will needed to assess a dose–response relationship.