²⁸Mg STUDIES IN MAGNESIUM‐DEFICIENT ANIMALS

Abstract

The first investigators to succeed in producing magnesium (Mg) deficiency experimentally were Orent and his coworkers,' who reported in 1934 that the rats used for their study showed a depletion of bone magnesium. Subsequent investigators2 have reported that the soft-tissue content of magnesium is not appreciably altered even in severe deficiency. When zsMg became available several years ago, we made a preliminary study of the dynamics of magnesium transfer in the tissues of rabbits maintained on a Mg-deficient diet for 30 days.3 The results of this study are reviewed in the present report, which also describes subsequent studies made in rabbits maintained on a diet extremely low in magnesium for four to six weeks. In addition to studying changes in blood constituents in such animals, we have done some preliminary in vitro studies on the intestinal transfer of magnesium in Mg-deficient and normal rabbits. THE EXTERNAL BALANCE AND Mg, STUDY Material and MethodsAdult male domestic rabbits were placed in individual stainless steel metabolism cages and were given unrestricted quantities of tap water containing 0.6 milliequivalent (mEq) of magnesium per liter. The basal diet used for rats by Mackenzie and Mackenzie4 was supplemented by the salt mixture of Hubbell and his coworkers,5 except that the magnesium salts were omitted. The composition of this diet, which contains 6.6 mEq of magnesium per kilogram, has been described previously.The z8 Mg was received as MgCI2 in concentrated HCI; the specific activity was on the order of 8-10 pc/mEq. The concentration of magnesium in the solution injected was 0.4 mEq/ml, and each injection contained 2 mEq.The procedures for collecting the samples for the external balance study, for measuring the exchangeable magnesium content ( Mge), and for assaying radioactivity have been described previ~usly.~ The magnesium concentration in urine and serum6 and in tissues7 was determined by a modification of the molybdivanadate method for phosphate.In the statistical analyses, the t test* was used to determine the significance either of the mean differences or of the differences between group means. A P of <0.01 was considered significant.This experiment was conducted as follows. During a control period of three days the eight rabbits in the test group were fed a balanced stock diet of compressed pellets, containing 172 mEq of magnesium per kilogram. Base-line data for body weight. serum magnesium concentration, and urinary excretion of 144

Relations physiologiques entre le magnésum et l'os

“…Le magnésium osseux est moins mobilisable chez le rat adulte que chez le jeune. Ainsi, Smith et Nisbet (1968,1972) (Kruse, Orent et McCollum, 1932 ;Orent, Kruse et McCollum, 1934 ;Tufts et Greenberg, 1938 (Chiemchaisri et Phillips, 1963), le veau (Blaxter, Rook et McDonald, 1954 ;Larvor et ai., 1964), le lapin (Aikawa et David, 1969), le porc (Miller et ai., 1965aet 19656), le poulain (Harrington, 1975, la poule (Cox et Sell, 1967), et la souris (Nielsen, 1973 Forbes, 1961 ;Blaxter, 1956 ;Lai, Singer et Armstrong, 1975 (Blaxter, 1956), le porc (Miller et al,1965a et (Blaxter, 1956) Belanger,1967 ;Hunt et Belanger,1972 ;Bogoroch et Belanger, 1975). Smith et Nisbet (1968,1972) Rayssiguier, 1977 : rat ; Anast, 1974 : homme ; Heaton,1964 : rat), mais tous les résultats ne concordent pas sur ce point : parfois la parathyroïdectomie est sans effet sur la magnésémie ou le magnésium osseux (Larvor et Durlach, 1971 (1963,1964,1965 (Sorensen, Hindberg et Bank-Mikkelsen, 1971 .…”

Magnesium and Bone Disease

“…There is a large body of literature dealing with experi mental magnesium deficiency in livestock [68], rats [1-4, 44, 54,69-92], mice [93], dogs [94,95], guinea pigs [96,97], horses [98], chicks [99,100] and rabbits [4,101).…”

Ψευδαργυρος Και Μαγνησιον Εις Τον Καρκινον Του Παγκρεατος

“…Καρδιακοί διαταραχαί ώς κα'ι νεφρολιθίασις είναι άλλα συνεπακόλουθα τής ένδειας μαγνησίου. Ό Aikawa (1969) (Waterlow 1976), ή έλκωτική κωλϊτις, ή νόσος TOÜ Crohn, ή έκτομή ικανού τμήματος έντερου, ή δυσλειτουργία είλεοστομίας, ή παρατεταμένη διούρησις, ό χρόνιος αλκοολισμός (Flink et al 1957), ή στεατόρροια, ή εντατική χορήγησις αλάτων ασβεστίου, τά διουρητικά του τύπου τής θειαζίδης καί φουροσεμίδης (Editorial 1975), ή χορήγησις μετεγχειρητικώς υγρών μέ μικράν περιεκτικό τητα εις μαγνήσιον (Editorial 1967), ενδοκρινικοί διαταραχαί (ύπεραλδοστερονισμός, διαβητική όξέωσις), νεφρικά νοσήματα (πυελονεφρϊτις, σπειραματονεφρίτις) (Wacker καί Parisi 1968 (β)) κακοήθη όστεολυτικά νεοπλάσματα κ.λ.π.…”