Measurement of growth and resorption of bone in rats fed meat diet

Abstract

Different coloured, fluorescent bone-s~eking chemicals, viz., tetracycline, Alizarin Red S, and DCAF, have been administered sequentially to weanling rats and the rate of formation and resorption of bone measured from hard-ground cross sections of the upper third of the diaphysis of the fenmr. On a meat diet, bodily growth is significantly restricted for the first week and then recovery occurs. While bones grow they fail to mineralize normMly and rapidly become fragile and rarefied. Resorption of bone is at first slow, then accelerates for a period of 2--3 weeks to about 15 t~/day and then slows again. While the rate of bone formation is reduced relative to normal bone, resorption proceeds at approximately two to three times the rate of bone growth. Microradiographic studies confirm that while resorption occurs on the endosteal margin and formation proceeds on the periostcal aspect of meat fed Ca-deficient rats, new bone is less calcified than that in control animals. Key words':Divers agents chimiques, color6s, fluorcseents et se localisant dans les os, ~ savoir la tdtraeyclinc, l'alazazine rouge Set le DCAF, ont 6t6 administr6 en sdric s des rats sevr6s ct on mesur6 le taux de la formation et de la r6sorption osseuse sur les coupes transversales du tiers sup6rieur de la diaphyse. Ici la formation osseuse p6riostale s'effeetue progressivement avec pen de changement endost6al. Avec Mimentation carn6e, la croissancc des rats est significativcment restreinte pendant la premib, re semaine, mais se rdtablit ensuite. Bien qu'il y air croissance des os, ceux-ci ne se min6ralisent pas normalement ct ils dcviennent rapidement fragiles et amincis. ],a r6sorption osseuse est lente d'abord, puis s'aeeelbre pendant 2--3 semaines pour atteindre un taux de 15 tx par jour, aprbs quoi elle se rMentit de nouveau. Bien que le taux de formation osseuse soit r6duit, en comparaison avec celui des os normaux, la r6sorption s'effectue environ deux g trois fois plus rapidement que la eroissance osseuse. Des 6tudes microradiographiques sur des rats g r6gime earn6 mais carenc6s en cMcium ont permis la constatation suivante: tandis que la r6sorption s'effectue i~ la marge endost6ale et que la formation osseuse a lieu sur l'aspect pgriost6M, la matibre osseusc nouvellement form6e est moins calcifi6e que ehez les t@mins, Einige farbige, fhmreszierende, knochensuchende Chemikalien, z. B. Tetraeyelin, AlazarinRot S und CDAF, wurden nacheinander an entw6hnten Ratten verabreicht, worauf man die Knoehenbildungs-und Knochenresorptionswerte an hartgeschliffenen Sehnitten des oberen Drittels der Diaphyse gemessen hat. Hier finder fortsehreitend periostale Knochenbildung start, mit geringer Ver~nderung des Endosteums. Bei FleischdiS~t wird das KSrperwaehstum w~hrend der ersten Woche erheblich beschriinkt; danach aber normalisiert es sieh wieder. Obwohl die Knoehen noch wachsen, zeigen sie keine normMe Mineralisierung und werden sehnell zerbreehlieh und diinn. Die Knochenresorption ist anfangs langsam, dann beschleunigt For reprints: Prof. E. Storey,

Lithium inhibition of bone mineralization and osteoid formation.

“…Our cointrol value for the periosteal mineralization rate, 3.57+0.43 gnm/day, correlates with the value of 3.2 ,tm/dav reported by previous investigators as the periosteal f'ormation rate in the femur of rats of similar weight (22). Subsequent studies by others with the rat tibia have reported periosteal and endosteal formation rates of 6.0 ,um/day and 2.9…”

“…The discrepancies in the reported bone mineralization rates in rats (22)(23)(24)(25) are most likely a result of differences in the experimental conditions, the weights and ages of the animals, and the bones studied. Both the rat tibia and f'emur are complicated by structural asymmetry and cortical drift (25)(26).…”

Fruit and vegetable consumption and skeletal health: is there a positive link?

“…Suprisingly, only a very small number of studies have focused attention with respect to bone health on populations consuming a diet highly dependent on animal foods, particularly that of meat (Hammond & Storey 1970). Mazess & Mather (1974) examined the bone mineral content of forearm bones in a population sample of Eskimo natives living off the north coast of Alaska.…”

“…While some studies published prior to 1990 found bone mineral mass to be higher in vegetarians, the five most recent studies carried out in the last decade have suggested no differences in bone mass between vegetarians and omnivores. Suprisingly, only a very small number of studies have focused attention with respect to bone health on populations consuming a diet highly dependent on animal foods, particularly that of meat (Hammond & Storey 1970). Mazess & Mather (1974) examined the bone mineral content of forearm bones in a population sample of Eskimo natives living off the north coast of Alaska.…”

Vollautomatische Herstellung von Knochenschliffen bei exakter Dickeneinstellung

“…1954[Kropp. , 1956Friend and Smith, 1964;Strndström, 1966;Hammond andStorey, 1972: Mc Queen et al. 1972;Holmstrand, 1975: Malcolm, 1975: Eger.…”