Mesangial cells
Cellulae mesangiales
Also known as: intraglomerular mesangium, mesangium, lacis cells, Goormaghtigh cells
Contractile, phagocytic, smooth-muscle-like cells with surrounding matrix that support the glomerular capillary loops; extraglomerular (lacis) mesangial cells form part of the juxtaglomerular apparatus.
Overview
Intraglomerular mesangial cells sit between the capillary loops, inside the GBM but not covered by endothelium on all sides. They (1) provide structural support, (2) contract in response to angiotensin II, ADH, endothelin and thromboxane (reducing filtration surface area and Kf) or relax with ANP and prostaglandins, (3) phagocytose and clear macromolecules and immune complexes trapped in the filter, and (4) secrete mesangial matrix, cytokines and growth factors.
Extraglomerular mesangial (lacis/Goormaghtigh) cells fill the angle between the afferent and efferent arterioles and the macula densa; they are gap-junction coupled to JG cells and mesangial cells and are thought to relay macula densa signals.
- Location
Glomerular mesangium (between capillary loops) and extraglomerular region at the vascular pole.
Function
- Structural support of capillary loops
- Regulate filtration surface (Kf) by contraction
- Phagocytose immune complexes and debris
- Secrete matrix and mediators
- Signal transmission within the JGA (lacis cells)
Clinical significance
IgA nephropathy
IgA1 immune complexes deposit in the mesangium → mesangial proliferation and episodic haematuria 1–3 days after a URTI (contrast post-streptococcal GN at 1–3 weeks). The commonest primary glomerulonephritis worldwide.
Diabetic nodules
Mesangial matrix expansion forms nodular Kimmelstiel–Wilson lesions in diabetic nephropathy.
Compiled from standard anatomy and physiology references — see the Urinary System sources. For education only; not medical advice.