Title: A Simple Method for Normalization of Aortic Contractility.

Authors: Jin, Lexiao; Lipinski, Alexandra; Conklin, Daniel J

Published In J Vasc Res, (2018)

Abstract: Vascular contractile function changes in proliferative vascular diseases, e.g. atherosclerosis, and is documented using isolated blood vessels; yet, many laboratories differ in their approach to quantification. Some use raw values (e.g., mg, mN); others use a "percentage of control agonist" approach; and others normalize by blood vessel characteristic, e.g. length, mass, etc. A lack of uniformity limits direct comparison of contractility outcomes. To address this limitation, we developed a simple 2-step normalization method: (1) measure blood vessel segment length (mm), area (mm2) and calculate volume (mm3); then, (2) normalize isometric contraction (mN) by segment length and volume. Normalized aortic contractions but not raw values were statistically different between normal chow and high-fat diet-fed mice, supporting the practical utility and general applicability of normalization. It is recommended that aortic contractions be normalized to segment length and/or volume to reduce variability, enhance efficiency, and to foster universal comparisons across isometric myography platforms, laboratories, and experimental settings.

PubMed ID: 29975955

MeSH Terms: Animals; Aorta, Thoracic/drug effects; Aorta, Thoracic/pathology; Aorta, Thoracic/physiopathology*; Diet, High-Fat; Disease Models, Animal; Dose-Response Relationship, Drug; In Vitro Techniques; Isometric Contraction*/drug effects; Male; Mice, Inbred C57BL; Myography/methods; Myography/standards*; Proof of Concept Study; Rats, Transgenic; Receptors, LDL/deficiency; Receptors, LDL/genetics; Reproducibility of Results; Vasoconstriction*/drug effects; Vasoconstrictor Agents/pharmacology