Pericyte

A pericyte, also known as Rouget cell [Rouget, CMB (1879). "Sur la contractilité capillaires sanguins. Comptes rendus de l’Académie des" "Sciences" 88: 916–918] or mural cell, is a mesenchymal-like cell, associated with the walls of small blood vessels. As a relatively undifferentiated cell, it serves to support these vessels, but it can differentiate into a fibroblast, smooth muscle cell, or macrophage as well if required. In order to migrate into the interstitium, the pericyte has to break the barrier, formed by the basement membrane, which can be accomplished by fusion with the membrane. They are important in blood brain barrier stability as well as angiogenesis. They have been implicated in blood flow regulation at the capillary level. Their expression of smooth muscule actin (SMA) and desmin, two proteins found in smooth muscle cells, and their adherence to the endovascular cells makes them very strong candidates for blood flow regulators in the microvasculature. Hemangiopericytoma is a malignant vascular tumor.

Pericytes express the enzyme, Aldose reductase, which is implicated in the development of diabetic retinopathy. Excess glucose is shunted down the polyol pathway and sorbitol accumulates. This osmotically active metabolite damages the pericytes in the retinal vessels resulting in the symptoms characterizing diabetic retinopathy.

References

* Rhodin, JA (1968). "Ultrastructure of mammalian venous capillaries, venules, and small collecting veins" " J Ultrastruct Res" 25(5): 452–500

* Sims, DE (1991). "Recent advances in pericyte biology. Implications for health and disease" "Can J Cardiol" 7(10): 431–443

ee also

* Hemangiopericytoma
* Mural cell
* Mesoangioblast
* Diabetic retinopathy caused by death of pericytes

External links

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* [http://www.udel.edu/Biology/Wags/histopage/illuspage/icv/icv17.gifDiagram at udel.edu]