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Updated: Jul 24, 2026
Hyperinsulinemic-Euglycemic Clamp in the Conscious Rat
Published on: February 7, 2011
Pulmonary vasodilation in the rat by insulin in vitro could indicate potential hazard for inhaled insulin
1Academic Department of Medicine, University of Hull, Hull, UK.
Aims/Hypothesis:
Hypoxic pulmonary vasoconstriction is an essential mechanism to prevent hypoxaemia in lung diseases. Insulin is known to be a systemic vasodilator but its effect on the pulmonary circulation is not known. Inhaled particulate insulin can generate locally high concentrations in the lung which could be physiologically important.
Methods:
We therefore studied the effects of insulin in vitro on isolated rat pulmonary artery in a small vessel myograph.
Results:
We have shown that pulmonary artery vasodilatation with insulin occurs in a dose-dependent manner. Pre-constriction with PGF2alpha can be abolished (105.7+/-2.9%, mean+/-SEM) and pre-constriction with hypoxia reduced (68.9+/-6.5%) by pharmacologically relevant concentrations of insulin. The characteristic phasic vasoconstriction by pulmonary vessel to hypoxia is substantially modified, resulting in sustained vasodilatation.
Conclusions/Interpretation:
These effects could be clinically important for patients using inhaled insulins who have acute or occult chronic lung disease.
