AJP - Cell Physiology, Vol 236, Issue 5 244-C248, Copyright © 1979 by American Physiological Society
Blood:bone disequilibrium. III. Linkage between cell energetics and Ca fluxes
W. F. Neuman, M. W. Neuman and C. R. Myers
Specially designed Ussing chambers were used for the quantitation of fluxes
of Ca2+ and lactate ions to and from viable calvaria taken from 2- to
3-day-old rat pups and young adult mice. The latter in vitro support Ca2+
levels comparable to plasma levels in vivo. The effects of various
metabolic inhibitors and parathyroid hormone were studied. The results
support previous findings that Ca influx into bone is a passive
concentration-dependent process not significantly affected by alterations
in the energy status of the bone cells. In large measure, the efflux from
bone also appears to be passive. However, significant alterations in the
calcium levels supported by efflux from bone were observed as acute effects
of metabolic inhibitors. Part of the metabolically derived efflux may be
attributed to acid production (aerobic glycolysis). However, part must be
ascribed to cellular activities not yet defined.
