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Updated: May 1, 2026
Author Spotlight: Advancing Human Cardiac Anatomy Through Multi-Scale Analysis of Hearts
Published on: June 28, 2024
Three-dimensional microvasculature in rat and human hearts using a non-injection Ca2+-ATPase method on thick and
Amaiak Chilingaryan1, Amayak M Chilingaryan2, Mikhail Chilingaryan2
11Department of Biology,Occidental College,1600 Campus Road,Los Angeles,CA 90041,USA.
Insights
A new non-injection staining method visualizes the microvascular bed in thick heart tissue sections. This technique clearly differentiates arterioles, venules, and capillaries, aiding cardiovascular research.
Area of Science:
- Cardiovascular Biology
- Histology
- Biochemistry
Background:
- Specific staining of myocardial microvasculature in thick sections is currently unavailable.
- Distinguishing between arterioles, venules, and capillaries in rat and human myocardium is challenging.
Purpose of the Study:
- To develop a novel non-injection staining technique for visualizing the microvascular bed (MVB) in thick myocardial sections.
- To enable specific differentiation of microvessels (arterioles, venules, capillaries) in human and rat heart tissue.
Main Methods:
- A non-injection technique utilizing phosphatase (ATPase) activity at high pH (10.5-11.5).
- Precipitation of released phosphate with calcium ions, converted to lead sulfide for visualization.
- Application to formalin-fixed human and rat myocardium, and human pericardium in thick (60-100 µm) and ultra-thick (300-500 µm) sections.
Main Results:
- Clear visualization of arterioles, venules, capillaries, and precapillaries in thick and ultra-thick myocardial sections.
- Specific staining of arteriolar smooth muscle cells, allowing differentiation from venular beds.
- Stained microvasculature visualized against an unstained background of muscle and connective tissue.
Conclusions:
- The described non-injection method effectively stains the myocardial microvascular bed in thick sections.
- This technique allows for precise differentiation of various microvessel types, including arterioles and venules.
- The method is valuable for studies of coronary microcirculation, cardiovascular pathology, and pharmacology.
Abstract:
Currently there are no methods available for staining rat and human myocardial microvasculature on thick sections that would allow for specific staining and differentiation of arterioles, venules, and capillaries. A non-injection technique is described that allows for labeling of the microvascular bed (MVB) in formalin-fixed pieces of the myocardium from humans and the white rat Rattus norvegicus, as well as human full-mount pericardium. Vessel staining is based on the activity of phosphatases (ATPases) and the precipitation of the released phosphate with calcium ions at high pH (pH 10.5-11.5). The resulting precipitate subsequently is converted to black or brown lead sulfide. The specificity of this reaction to vessels of the MVB allows arterioles, venules, capillaries, and pre- and postcapillaries to be clearly visualized in thick (60-100 µm) and ultra-thick (300-500 µm) sections against an unstained background of muscle and connective tissue. In addition, smooth muscle cells of arterioles are also stained allowing for differentiation between arteriolar and venular beds. These observations have not been reported in rat or human myocardium using other methods. This procedure should benefit studies of coronary microcirculation in experimental and pathological conditions, as well as in pharmacological investigations.
