In situ perfusion of rat lungs: stability and effects of oxygen tension

Abstract

A new method for perfusion of rat lungs in situ was developed for metabolic studies. The pulmonary circulation was cannulated without contacting the lungs, which remained in the thoracic cage. Perfusion was continued for up to 4 h with Krebs-Henseleit bicarbonate buffer, equilibrated with 95% O2- 5% CO2 and containing 4.5% bovine serum albumin, 5.6 mM glucose, and levels of amino acids normally found in rat plasma. At an arterial pressure of 20 cmH2O flow remained constant (10.9 ml/min.100 g body wt) and appeared evenly distributed among the lobes. Tidal volume was 1 ml/100 g body wt (72/min); positive end-expiratory pressure was 2 cmH2O. The preparation remained stable and metabolically active for 4 h, as evidenced by a minimal decline in dry-to-wet weight ratio, constant levels of ATP and glycogen, a high ratio of glucose uptake to lactate production, and a linear rate of incorporation of [14C]phenylalanine into protein. The lungs were unaffected when perfusate oxygen was reduced to a more physiological level (20% O2-75% N2-5% CO2). In the presence of 95% N2-5% CO2 dry-to-wet weight ratio, ATP, glycogen, and amino acid incorporation decreased, while lactate production doubled.

NS1619-Induced Vasodilation is Enhanced and Differentially Mediated in Chronically Hypoxic Lungs

“…The heart and lungs were then trimmed free from the thorax and diaphragm, removed en bloc, and suspended. The pulmonary vasculature was continuously perfused at 7 ml/min with Earle's balanced salt solution, maintained at 37°C, and aerated with 95 % O 2 -5 % CO 2 [15] and 21 % O 2 /5 % CO 2 /74 % N 2 [16] for the normoxic and hypoxic lung preparations, respectively. Select experiments were repeated using 21 % O 2 /5 % CO 2 / 74 % N 2 aerated perfusate in normoxic lung preparations.…”

A comparison of nucleoside transport and metabolism in hypertensive and normotensive rats.

“…9 Briefly, a ligature was loosely placed around the pulmonary artery and aorta, and a second ligature was placed under the pulmonary artery and aorta and rotated under the heart to surround the pulmonary veins and left atrium. A PE-240 cannula with a flanged end was inserted at the base of the left ventricle and gently advanced through the mitral valve directly into the atrial appendage.…”

Isolated perfused lung preparation for studying altered gaseous environments.

“…The me-FIGURE 1. Schematic of isolated perfused lung preparation with numbers indicating various components: (1) 02-CO2 mixture; (2) humidifier; (3) respirator; (4) organ and blood reservoir; (5) bubble trap and pressure dampener; (6) to pulmonary artery; (7) sample port; (8) …”

“…Although other species can be used, our technique is devised for the laboratory rat; partly because much of the data on tissue metabolism is derived from the rat. In particular, the rat lung has been studied in detail (2,5,9,10,14,15,(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27).…”

“…Mean ± SEa Glucose, ,umole/hr-g dry lung Lactate, ,umole/hr-g dry lung aThese data were obtained from lungs ventilated with 95% 02-5% CO2 and perfused with Krebs-Henseleit bicarbonate buffer for 1 to 2 hr (2,16,17,22). Flow rates ranged from 10 to 15 mL/min and ventilation ranged between 30 and 60 cycles/min.…”