Effect of relatively long-term hypomagnesemia on the chondro-osseous features of the rat vertebrae.
Cartilage and bone in the lumbar vertebrae of magnesium-deficient (LoMg) rats were studied after 4 and 8 weeks of Mg restriction. LoMg animals receiving 0.03% Mg intake had significantly reduced serum Mg levels compared to controls (receiving 0.2% Mg) at both 4 weeks [0.66 +/- 0.06 mg% mean +/- SE (n = 10)] and 8 weeks [0.74 +/- 0.02 mg% (n = 3)] of study. Mean width of the vertebral growth plate was significantly decreased in LoMg animals at 4 weeks [54.7 +/- 3.5 microns (n = 9) vs. control 68.0 +/- 3.0 microns (n = 6)] and 8 weeks [39.5 +/- 2.8 microns (n = 3) vs. control 57.5 +/- 3.6 microns (n = 3)]. The mean number of cells/cartilage column in the growth plate was also less at 4 weeks [5.8 +/- 0.18 (n = 5) vs. control 7.2 +/- 0.19 (n = 5)] and 8 weeks [4.9 +/- 0.19 (n = 3) vs. control 6.2 +/- 0.08 (n = 3)]. A significant proportion of LoMg animals possessed decreased pericolumnar diastase-PAS reactivity at 4 and 8 weeks of study; this indicates a decrease in cartilage glycoprotein content during Mg deficiency. Quantitative histomorphometric analysis determined that vertebral trabecular bone possessed significantly decreased percentage of osteoid surface (2.49 +/- 0.54 vs. control 6.98 +/- 2.8) and significantly decreased percentage of osteoid area (0.18 +/- 0.05 vs. control 0.82 +/- 0.38) after 4 weeks of Mg deficiency. These findings document significant alterations in both bone and cartilage histologic features following relatively long-term Mg deficiency.
Gruber
H E
HE
Baxter Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, Carolinas Medical Center, Charlotte, N.C. 28232.
Massry
S G
SG
Brautbar
N
N
D000818:Animals; D002118:Calcium / Q000097:blood; D002356:Cartilage / Q000737:chemistry / Q000473:pathology*; D006023:Glycoproteins / Q000032:analysis; D006132:Growth Plate / Q000473:pathology; D008159:Lumbar Vertebrae / Q000473:pathology*; D008274:Magnesium / Q000097:blood*; D008275:Magnesium Deficiency / Q000378:metabolism / Q000473:pathology*; D008297:Male; D010503:Periodic Acid-Schiff Reaction; D010758:Phosphorus / Q000097:blood; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors
D006023:Glycoproteins; D010758:Phosphorus; D008274:Magnesium; D002118:Calcium