An ACTH-induced renal glomerular lesion in the mouse: immunofluorescence microscopy

Area of Science:

• Nephrology
• Immunology
• Endocrinology

Background:

• Adrenocorticotropic hormone (ACTH) is known to induce glomerular lesions.
• The precise mechanisms and locations of plasma protein deposition in these lesions are not fully understood.

Purpose of the Study:

• To investigate the deposition patterns of plasma proteins, specifically immunoglobulins (IgG, IgM), complement (C3), and albumin, in ACTH-induced glomerular lesions in mice.
• To explore the potential role of the juxtaglomerular apparatus (JGA) in plasma protein handling within the kidney.

Main Methods:

• Mice were treated with ACTH to induce glomerular lesions.
• Kidney tissues were examined using light microscopy and immunofluorescence microscopy.
• Immunofluorescence staining was performed for IgG, IgM, C3, and albumin.

Main Results:

• Light microscopy confirmed typical ACTH-induced glomerular lesions.
• Immunofluorescence revealed intense IgG and IgM staining in the extraglomerular mesangium (EGM) and Bowman's space.
• Accumulation of C3 and albumin was observed in the EGM, Bowman's space, and glomerular tuft, with patterns similar but less frequent in control mice.

Conclusions:

• ACTH treatment in mice leads to increased accumulation of plasma proteins within the JGA.
• These findings suggest a potential role for the JGA in the clearance of plasma proteins from the glomerulus and/or directly from circulation.