Abstract: The present invention provides methods for treating inflammation in the lungs of a subject in need of such treatment, comprising the step of administering an effective amount of a composition comprising b-nicotinamide adenine dinucleotide to the subject. Also provided is a method of increasing integrity of a vascular barrier in a subject, comprising the step of contacting one or both of human P2Y1 receptors or P2Y11 receptors in the subject with an amount of a composition comprising beta-nicotinamide adenine dinucleotide effective to activate the receptors; wherein activation thereof increases the integrity of the vascular barrier in the subject.