Intraglomerular mesangial cell
|Intraglomerular mesangial cell|
Renal corpuscle. The entire structure is the renal corpuscle. The blue structure (A) is the Bowman's capsule (2 and 3). The pink structure is the glomerulus with its capillaries. At the left, blood flows from the afferent areteriole (9), through the capillaries (10), and out the efferent arteriole (11). The mesangium is the pink structure inside the glomerulus between the capillaries (5a) and extending outside the glomerulus (5b).
There are five known functions of intraglomerular mesangial cells: structural support of glomerular capillaries, regulation of the glomerular filtration rate, mesangial matrix formation, phagocytosis, and monitoring of capillary lumen glucose concentration.
Intraglomerular mesangial cells have contractile activity. The initiation of contraction of mesangial cells is similar to that of smooth muscle. Contraction of mesangial cells is coupled with contraction of the basement membrane of the endothelium of glomerular capillaries. This causes a decrease in surface area of the basement membrane and thus a decreased glomerular filtration rate.
Intraglomerular mesangial cells phagocytize glomerular basal lamina components and immunoglobulins. They are an unusual example of phagocytic cells derived from smooth muscle and not monocytes. Intraglomerular mesangial cells aid neutrophils in removing other mesangial cells undergoing apoptosis, and other debris.
Intraglomerular mesangial cells monitor capillary lumen glucose concentration via processes sent into the capillary lumen.
- Junqueira L.C., Carneiro J. in Kelley R.O. (2003). Basic histology, 10. izdaja. New York, London, Toronto: Lange Medical Books McGraw-Hill.
- Histology image: 16006loa – Histology Learning System at Boston University