Insulin clearance by perfused rat lung

The clearance of insulin has been demonstrated in the perfused in situ rat lung. Porcine insulin added to the perfusion medium at 50 microunits/l was cleared at 6.3 U/h in lungs from fed animals, 6.1 U/h in fasted animals and 15.7 U/h in diabetic rat lungs. At a higher concentration of insulin (500 microunits/l) increased clearance was observed in lungs from both fed, fasted and diabetic animals, 33.0, 36.0 and 56.5 U/h respectively. It is suggested that the clearance of insulin by the lung is dependent on metabolic state of the animal.