TY - JOUR
T1 - The effects of chronic vitamin D deficiency on the skeleton in the adult rabbit
AU - Brommage, R.
AU - Miller, S. C.
AU - Langman, C. B.
AU - Bouillon, R.
AU - Smith, R.
AU - Bourdeau, J. E.
N1 - Funding Information:
Acknowledgments : 'Ibis study was supported by a NIH New Investigator Research Award AM37154/AR38784 (R . Brommage) . N1H grants AM35985 (JEB) . DE06007 (SCM) and DK3682I (CBL), U .S . Department of Energy Contract DEAC0276EY00119 (SCM) and by grant number 3 .0029 .85 from the Belgian National "Fonds voor Wetenschappclijk Ondcrzoek" (R . Bouillon) and was performed during the tenure of an Established investigator-ship from the American Heart Association and with funds contributed in part by the Chicago Heart Association (JEB) . The technical assistance of A,L . Theisen . J . . McNeill, N . Knutsen, and W. Coopmans is gratefully acknowledged . Secretarial assistance was provided by R . Sage and R .B . Beckman.
PY - 1988
Y1 - 1988
N2 - Albino rabbits were fed a 1.0% Ca, 0.5% P, vitamin D-deficient diet for 11.7 to 31.3 mo. Control rabbits were fed either this diet with the addition of 2.2 units/gm of vitamin D3 or a standard laboratory rabbit ration. Serum levels of 25-OH-D and 1,25-(OH)2D were both undetectable in all vitamin D-deficient rabbits but were present at levels typically found in other species in the control rabbits. Vitamin D deficiency resulted in elevated serum PTH values but did not produce significant changes in serum Ca levels, femur length, femur ash weight to body weight ratio, or tibial breaking strength. The vitamin D-deficient rabbits could be readily separated into two distinct subgroups. Four of these rabbits were normo-phosphatemic (P = 3.7 ± 0.4 mg/dl) whereas the other five were severely hypophosphatemic (P = 0.8 ± 0.2 mg/dl). During the last 10 days of the study the control and normo-phosphatemic vitamin D-deficient rabbits were in positive Ca and zero P balance. The hypophosphatemic vitamin D-deficient rabbits were in zero Ca and negative P balance. This negative P balance resulted from a net intestinal secretion, as urinary P excretion was negligible. Femur ash weight as a percentage of dry weight was decreased in hypophosphatemic but not the normophosphatemic vitamin D-deficient rabbits. Histomorphometric analyses indicated the bones from the normophosphatemic vitamin D-deficient rabbits were normal. In contrast, vertebral trabecular bone from the hypophosphatemic rabbits contained large amounts of osteoid that was not mineralizing, as indicated by a failure to take up the fluorescent label calcein. Similarly, tibial cortical bone from these rabbits was also not mineralizing properly and contained localized areas of high porosity near the endosteal surface. These results indicate that, on a 1.0% Ca, 0.5% P diet, chronic vitamin D deficiency in the adult rabbit results in intestinal P malabsorption with a resulting renal P conservation. Although some vitamin D-deficient rabbits are able to maintain normal serum P levels, in other rabbits serum P levels fall dramatically. The resulting hypophos-phatemia in these rabbits leads to inadequate skeletal mineralization and the classical signs of osteomalacia.
AB - Albino rabbits were fed a 1.0% Ca, 0.5% P, vitamin D-deficient diet for 11.7 to 31.3 mo. Control rabbits were fed either this diet with the addition of 2.2 units/gm of vitamin D3 or a standard laboratory rabbit ration. Serum levels of 25-OH-D and 1,25-(OH)2D were both undetectable in all vitamin D-deficient rabbits but were present at levels typically found in other species in the control rabbits. Vitamin D deficiency resulted in elevated serum PTH values but did not produce significant changes in serum Ca levels, femur length, femur ash weight to body weight ratio, or tibial breaking strength. The vitamin D-deficient rabbits could be readily separated into two distinct subgroups. Four of these rabbits were normo-phosphatemic (P = 3.7 ± 0.4 mg/dl) whereas the other five were severely hypophosphatemic (P = 0.8 ± 0.2 mg/dl). During the last 10 days of the study the control and normo-phosphatemic vitamin D-deficient rabbits were in positive Ca and zero P balance. The hypophosphatemic vitamin D-deficient rabbits were in zero Ca and negative P balance. This negative P balance resulted from a net intestinal secretion, as urinary P excretion was negligible. Femur ash weight as a percentage of dry weight was decreased in hypophosphatemic but not the normophosphatemic vitamin D-deficient rabbits. Histomorphometric analyses indicated the bones from the normophosphatemic vitamin D-deficient rabbits were normal. In contrast, vertebral trabecular bone from the hypophosphatemic rabbits contained large amounts of osteoid that was not mineralizing, as indicated by a failure to take up the fluorescent label calcein. Similarly, tibial cortical bone from these rabbits was also not mineralizing properly and contained localized areas of high porosity near the endosteal surface. These results indicate that, on a 1.0% Ca, 0.5% P diet, chronic vitamin D deficiency in the adult rabbit results in intestinal P malabsorption with a resulting renal P conservation. Although some vitamin D-deficient rabbits are able to maintain normal serum P levels, in other rabbits serum P levels fall dramatically. The resulting hypophos-phatemia in these rabbits leads to inadequate skeletal mineralization and the classical signs of osteomalacia.
KW - Bone histomorphometry
KW - Ca balance
KW - Osteomalacia
KW - P balance
KW - Rabbit
KW - Vitamin D deficiency
UR - http://www.scopus.com/inward/record.url?scp=0023755605&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0023755605&partnerID=8YFLogxK
U2 - 10.1016/8756-3282(88)90002-6
DO - 10.1016/8756-3282(88)90002-6
M3 - Article
C2 - 3166829
AN - SCOPUS:0023755605
SN - 8756-3282
VL - 9
SP - 131
EP - 139
JO - Bone
JF - Bone
IS - 3
ER -
