title: Inhibition of histamine-induced bronchoconstriction in Guinea pig and Swine by pulsed electrical vagus nerve stimulation.
abstract: Objective. Smooth muscle help regulate the diameter of the airways and their constriction can contribute to the pathology of acute asthma attacks. This study sought to determine if applying a specific electrical signal to the vagus nerve (VN) could minimize histamine-induced bronchoconstriction. Methods. Sixteen guinea pigs and three swine were anesthetized and had bipolar electrodes positioned on the cervical VNs. After the animals stabilized, i.v. histamine was titrated to elicit a moderate 2-4 cm H(2) O increase in pulmonary inflation pressure (Ppi). Histamine was then dosed with or without concurrent low voltage VN stimulation. Results. The peak change in Ppi following a histamine challenge was reduced in the guinea pig by VN stimulation (3.4 ± 0.4 vs. 2.1 ± 0.2 cm H(2) O, p < 0.001). The results were confirmed in a limited study in swine and indicate VN treatment is applicable to larger animals. Conclusion. This study suggests that VN stimulation can reduce bronchoconstriction and may prove useful as a rescue therapy in the treatment of acute asthma.
authors.affiliation: Electrocore LLC, Morris Plains, NJ, USA;              Department of Anesthesiology and Critical Care Medicine, Johns Hopkins Medical Institutions, Baltimore, MD, USA; and              Department of Anesthesiology, Columbia University, New York, NY, USA.
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Hoffmann
authors.forename: Steven
authors.initials: S
authors.lastname: Mendez
authors.forename: Peter
authors.initials: P
authors.lastname: Staats
authors.forename: Charles W
authors.initials: CW
authors.lastname: Emala
authors.forename: Puyun
authors.initials: P
authors.lastname: Guo