Metabolic alkalosis decreases bone calcium efflux by suppressing
osteoclasts and stimulating osteoblasts.
Bushinsky, David A.
Nephrology Unit, Department of Medicine University of Rochester
School of Medicine, Rochester, NY 14642
APStracts 3:0047F, 1996.
In vivo and in vitro evidence indicates that metabolic acidosis, which
may occur prior to complete excretion of end products of metabolism,
increases urinary calcium excretion. The additional urinary calcium
is almost certainly derived from bone mineral. Neutralization of this
daily acid load, through the provision of base, decreases calcium
excretion suggesting that alkali may influence bone calcium
accretion. To determine if metabolic alkalosis alters net calcium
efflux (JCa+) from bone and bone cell function we cultured neonatal
mouse calvariae for 48 h in either control medium (pH nearly equal to
7.4, [HCO3-] nearly equal to 24), medium simulating mild alkalosis
(pH nearly equal to 7.5, [HCO3-]=31) or severe alkalosis (pH nearly
equal to 7.6, [HCO3-] nearly equal to 39) and measured JCa+ and the
release of osteoclastic [beta]-glucuronidase and osteoblastic
collagen synthesis.
Received 28 February 1996; accepted in final form 28 February
1996.
APS Manuscript Number F375-5.
Article publication pending Am. J. Physiol. (Renal Fluid Electrolyte
Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 20 March 96