Document Type

Article

Publication Date

2026

Publication Title

Vascular Pharmacology

Volume

163

Pages

107615

DOI

10.1016/j.vph.2026.107615

Abstract

The human lung normally accommodates exercise-induced cardiac output increases mainly via recruitment of non-concomitantly perfused pulmonary capillaries. Recruitment is detectable by measuring the first-pass transpulmonary metabolism of ³H-benzoyl-Phe-Ala-Pro, providing an estimate of functional capillary surface area (FCSA). Pulmonary arterial hypertension (PAH) results from luminal narrowing of small precapillary arterioles, reducing downstream perfused FCSA. We hypothesized that exercising PAH patients would not be able to recruit FCSA normally. We studied two patients with severe PAH. Despite exercising to maximal dyspnea, neither could recruit FCSA. These limited data are the first direct measurements of FCSA in exercising PAH patients.

Rights

© 2026 The Authors

This is an open access article under the Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0) License.

Data Availability

Article states: "The data that have been used are confidential."

Original Publication Citation

Langleben, D., Orfanos, S. E., Fox, B. D., Giovinazzo, M., Kaddis, M., & Catravas, J. D. (2026). Decreased exercise-induced pulmonary capillary recruitment in pulmonary arterial hypertension. Vascular Pharmacology, 163, Article 107615. https://doi.org/10.1016/j.vph.2026.107615

ORCID

0000-0002-5098-295X (Catravas)

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