Intussusception is a widespread phenomenon that occurs in the vascular systems of all species and organs investigated so far. Some essential characteristics, which distinguish it from sprouting, are discussed in the following sections.
Intussusceptive Microvascular Growth Is Achieved with a Low Rate of Endothelial Proliferation
Our own morphometric investigations on the lung and CAM, as well as data from the literature, indicate that the intussusceptive process is associated with low endothelial proliferation. This means that capillary beds growing by intussuception achieve their rapid expansion by redistributing the preexisting total endothelial cell volume by thinning and spreading of the cytoplasmic leaflets. This was confirmed by our comparative studies of different organs before and after the onset of intussusception, as well as by reports in the literature [3-5, 8, 9].
Capillaries Formed by Intussusception Are Less Leaky
Intussusception is characterized by physiological levels of vascular transpermeability. This is an essential condition for uncompromised tissue and organ function. This important benefit could be the reason why after the formation of the primary capillary plexus by vasculogenesis or sprouting, additional vascular growth and remodeling during both embryonic development and postnatal life occurs by intussusception. The low transpermeability could furthermore be an essential factor for the resistance to chemotherapy treatment in tumors growing predominantly by intussusception .
Intussusception Is Energetically and Metabolically More Cost Effective
In contrast to sprouting, massive cell proliferation, extensive basement membrane degradation, and invasion of the surrounding tissue is not required in intussusception. Intussusception represents a phenomenally simple angiogenic mechanism possessing a high morphogenic potential and plasticity, and which is simultaneously energetically and metabolically more economical. This would explain why intussusceptive microvascular growth is triggered immediately after the formation of the primitive capillary plexus by vasculogenesis or sprouting.
Was this article helpful?
This ebook provides an introductory explanation of the workings of the human body, with an effort to draw connections between the body systems and explain their interdependencies. A framework for the book is homeostasis and how the body maintains balance within each system. This is intended as a first introduction to physiology for a college-level course.