A robust cardiac slicing approach was developed for optical mapping of transmural gradients in transmembrane potential (Vm ) and intracellular Ca2+ transient (CaT) of murine heart. Significant transmural gradients in Vm and CaT were observed in the left ventricle. Frequency-dependent action potentials and CaT alternans were observed in all ventricular regions with rapid pacing, with significantly greater incidence in the endocardium than epicardium. The observations demonstrate the feasibility of our new approach to cardiac slicing for systematic analysis of intrinsic transmural and regional gradients in Vm and CaT.
Transmural and regional gradients in membrane potential and Ca2+ transient in the murine heart are largely unexplored. Here, we developed and validated a robust approach which combines transverse ultra-thin cardiac slices and high resolution optical mapping to enable systematic analysis of transmural and regional gradients in transmembrane potential (Vm ) and intracellular Ca2+ transient (CaT) across the entire murine ventricles. The voltage dye RH237 or Ca2+ dye Rhod-2 AM were loaded through the coronary circulation using a Langendorff perfusion system. Short-axis slices (300 μm thick) were prepared from the entire ventricles (from the apex to the base) by using a high-precision vibratome. Action potentials (APs) and CaTs were recorded with optical mapping during steady-state baseline and rapid pacing. Significant transmural gradients in Vm and CaT were observed in the left ventricle, with longer AP duration (APD50 and APD75 ) and CaT duration (CaTD50 and CaTD75 ) in the endocardium compared with that in the epicardium. No significant regional gradients were observed along the apico-basal axis of the left ventricle. Interventricular gradients were detected with significantly shorter APD50 , APD75 and CaTD50 in the right ventricle compared with left ventricle and ventricular septum. During rapid pacing, AP and CaT alternans were observed in most ventricular regions, with significantly greater incidence in the endocardium in comparison with epicardium. In conclusion, these observations demonstrate the feasibility of our new approach to cardiac slicing for systematic analysis of intrinsic transmural and regional gradients in Vm and CaT in murine ventricular tissue.
This research output has an Altmetric Attention Score of 4. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 10 December 2024.
All research outputs
#11,982,413
of 34,526,284 outputs
Outputs from Journal of Physiology
#4,912
of 12,289 outputs
Outputs of similar age
#148,772
of 373,459 outputs
Outputs of similar age from Journal of Physiology
#88
of 182 outputs
Altmetric has tracked 34,526,284 research outputs across all sources so far. This one has received more attention than most of these and is in the 64th percentile.
So far Altmetric has tracked 12,289 research outputs from this source. They typically receive a lot more attention than average, with a mean Attention Score of 12.4. This one has gotten more attention than average, scoring higher than 58% of its peers.
Older research outputs will score higher simply because they've had more time to accumulate mentions. To account for age we can compare this Altmetric Attention Score to the 373,459 tracked outputs that were published within six weeks on either side of this one in any source. This one has gotten more attention than average, scoring higher than 59% of its contemporaries.
We're also able to compare this research output to 182 others from the same source and published within six weeks on either side of this one. This one is in the 49th percentile – i.e., 49% of its contemporaries scored the same or lower than it.
