Retinal Changes in Magnesium-deficient Rats

• Published in: Experimental eye research Vol. 72; no. 1; pp. 23 - 32
• Main Authors: Gong, Huaqing, Amemiya, Tsugio, Takaya, Kenichi
• Format: Journal Article
• Language: English
• Published: London Elsevier Ltd 01.01.2001; Elsevier
• Subjects: Animals; Biological and medical sciences; Calcium - blood; electron microscopy; Eye and associated structures. Visual pathways and centers. Vision; Female; Fundamental and applied biological sciences. Psychology; magnesium; Magnesium - blood; magnesium deficiency; Magnesium Deficiency - blood; Magnesium Deficiency - pathology; Male; Microscopy, Electron; Necrosis; Pigment Epithelium of Eye - pathology; rat; Rats; Rats, Wistar; retina; Retina - pathology; secondary ion mass spectrometry microscopy; Spectrometry, Mass, Secondary Ion; Vertebrates: nervous system and sense organs; electron microscopy; magnesium; rat; magnesium deficiency; retina; secondary ion mass spectrometry microscopy; Eye; Visual system; Trace element; Vertebrata; Mammalia; Rat; Deficiency; Rodentia; Retina; Magnesium
• ISSN: 0014-4835; 1096-0007
• DOI: 10.1006/exer.2000.0928

The purpose of the present study is to investigate the retina in magnesium (Mg) deficiency and elucidate the local functions of trace elements. After delivery, mother Wistar Kyoto rats were fed a low Mg diet containing 0.1mg Mg per 100g diet with all other nutrients and distilled and deionized water. Infant rats were suckled by their mother rats for 21 days and then fed the same Mg-deficient diet. Control mother rats were fed commercial rat pellets containing 24mg Mg per 100g diet and all other nutrients. The retinas were examined by electron microscopy and secondary ion mass spectrometry (SIMS) microscopy at 6 weeks of age. In the Mg-deficient rats serum Mg levels were significantly lower and calcium (Ca) levels higher than in the control rats. The retinas of Mg-deficient rats showed multifocal necrosis in the pigment epithelial cells; photoreceptor cell outer segments were deformed near the necrotic cells, and some pigment epithelial cells contained many lamellar bodies. Many photoreceptor cell nuclei showed pyknotic (apoptosis-like) changes. SIMS images showed lower Mg concentration throughout the retina of the Mg-deficient rats, and the ratio of Ca to Mg concentration was significantly higher than in the control rats. Mg deficiency induces multifocal necrosis in the retinal pigment epithelial cells and pyknotic (apoptosis-like) changes in the photoreceptor cell nuclei. The changes in Mg-deficient retinas may be due to an imbalance in the distribution of Mg and Ca trace elements.