Optimization of resting tension for wire myography in male rat pulmonary arteries

Rira Choi, Roshini Narayanan, Sandeep Jandu, William Savage, Sara Kang, Bulouere Wodu, Kavitha Nandakumar, Lakshmi Santhanam, Jochen Steppan

Research output: Contribution to journalArticlepeer-review

Abstract

Wire myography to test vasomotor functions of blood vessels ex-vivo are well-established for the systemic circulation, however, there is no consensus on protocols for pulmonary arteries. We created a standardized wire myography protocol for healthy rat PAs and validated this in a pulmonary hypertension (PH) model. Vessels stretched to higher initial tensions (5.0, 7.5 and 10.0 mN) exhibited a uniform response to phenylephrine, a larger dynamic range, and lower EC50 values. The endothelium-mediated relaxation showed that moderate tensions (7.5 and 10.0 mN) produced robust responses with higher maximum relaxation and lower EC50 values. For endothelium independent responses, the higher initial tension groups had lower and more consistent EC50 values than the lower initial tension groups. Pulmonary arteries from rats with PH were more responsive to vasoactive drugs when subjected to a higher initial tension. Notably, vessels in the PH group subjected to 15.0 mN exhibited high dynamic ranges in contractile and relaxation responses without tearing. Lastly, we observed attenuated cholinergic responses in these vessels—consistent with endothelial dysfunction in PH. Therefore, a moderate initial tension of 7.5–10.0 mN is optimal for healthy rat pulmonary arteries and a higher initial tension of 15.0 mN is optimal for pulmonary arteries from animals with PH.

Original languageEnglish (US)
Article numbere15911
JournalPhysiological Reports
Volume12
Issue number1
DOIs
StatePublished - Jan 2024

Keywords

  • protocol
  • pulmonary arterial hypertension
  • pulmonary hypertension
  • remodeling
  • vascular stiffness
  • wire myography

ASJC Scopus subject areas

  • Physiology
  • Physiology (medical)

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