Myography of isolated blood vessels: Considerations for experimental design and combination with supplementary techniques

Abstract

The study of the mechanisms of regulation of vascular tone is an urgent task of modern science, since diseases of the cardiovascular system remain the main cause of reduction in the quality of life and mortality of the population. Myography (isometric and isobaric) of isolated blood vessels is one of the most physiologically relevant approaches to study the function of cells in the vessel wall. On the one hand, cell-cell interactions as well as mechanical stretch of the vessel wall remain preserved in myography studies, in contrast to studies on isolated cells, e.g., cell culture. On the other hand, in vitro studies in isolated vessels allow control of numerous parameters that are difficult to control in vivo. The aim of this review was to 1) discuss the specifics of experimental design and interpretation of data obtained by myography and 2) highlight the importance of the combined use of myography with various complementary techniques necessary for a deep understanding of vascular physiology.

Differences in vasomotor function of mesenteric arteries between Ossabaw minipigs with predisposition to metabolic syndrome and Göttingen minipigs

“…Ossabaw minipigs with a polygenic predisposition for the development of the metabolic syndrome, but without the diseased phenotype had smaller vessel diameter and higher baseline developed force of contraction in mesenteric arteries than Göttingen minipigs, without such predisposition. These differences suggest a higher active tension of the vascular smooth muscle cells at baseline ( 34 , 53 ) of the Ossabaw than Göttingen minipig arteries. Ossabaw minipig arteries were further characterized by more pronounced vasoconstriction to norepinephrine and less pronounced endothelium-dependent and endothelium-independent vasodilation than those from Göttingen minipigs.…”

“…Ossabaw minipig arteries were further characterized by more pronounced vasoconstriction to norepinephrine and less pronounced endothelium-dependent and endothelium-independent vasodilation than those from Göttingen minipigs. This again suggests that Ossabaw minipig arteries have a higher contractile state and thus higher vascular resistance ( 33 , 34 ). The lesser vasodilation to both, endogenous (endothelium-dependent) and exogenous (endothelium-independent) nitric oxide in Ossabaw than in Göttingen minipigs may indicate that endothelial dysfunction does not contribute quantitatively to the observed differences in vasomotor function between the two pig strains.…”

“…We used adult but still young pigs, and sex differences in vasomotor function result not only from genetic differences between the sexes but also from sex- and age-related changes in hormones ( 81 , 82 ). We determined the vessel diameter in the presence of calcium; the use of a calcium-free buffer would have allowed the determination of the vessel diameter in a completely relaxed state ( 34 ). We used only norepinephrine as a vasoconstrictor and only one endothelium-dependent and one endothelium-independent vasodilator.…”

“…The vessels were equilibrated for a further 30 min with frequent buffer changes. The baseline developed force of contraction was measured ( 33 , 34 ). Vasoconstriction was then repeatedly induced by depolarization of the vascular smooth muscle cell membrane with potassium chloride (KCl twice 0.6 × 10 −1 mol/L and twice 1.2 × 10 −1 mol/L over 5 min each).…”

“…The process of atherosclerosis is a generalized process affecting all vascular beds, which has been suggested to start in resistance arteries before changes in conduit arteries ( 31 , 32 ). We used mesenteric resistance arteries, as they are easily accessible and feature a high reproducibility in isometric force measurements ( 33 , 34 ). For comparison of in vitro vascular function between these minipig strains, we used pigs undergoing cardioprotection studies ( 35 – 37 ), in compliance with the replacement, refinement, and reduction, the “3R”, of animals in research ( 38 , 39 ).…”