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Responses of the osteocyte lining cell complex the bone cell unit to calcitonin

1980; Pergamon Press; Volume: 2; Issue: 2 Linguagem: Inglês

10.1016/0221-8747(80)90007-7

1878-061X

J. L. Matthews, R. V. Talmage, R. Doppelt,

Vitamin D Research Studies

Abstract A calcium phosphate complex forms in the lacunar and canalicular spaces following calcitonin administration. This complex is demonstrated morphologically by potassium pyroantimonate fixation or by incubation of tissue in aqueous medium for up to 9 days. This latter treatment results in a transformation of the calcium phosphate complex and free ions to mineral crystals. Specimens viewed with transmission electron microscopy at 15 minutes after hormone administration show a maximal presence of this complex. By 30 minutes post-hormone and post-incubation the amount of mineral crystals observed is reduced to a minimal amount. The amount of this complex observed at 1 and 2 hours after calcitonin then increases. Incubation of the 30 minutes post-hormone specimens in an acidic medium enhances conversion to crystals while incubation in a basic medium is without effect. This observation confirms that available electrolytes and other necessary elements are present at the 30 minutes post-calcitonin period, but an acid milieu is necessary to achieve crystal formation. The presence of the complex is dependent upon calcitonin, as control incubated specimens did not produce the mineral crystals. The complex is thus presumed to reflect changes in the bone fluid resulting from calcitonin action on the adjacent bone cells. In addition, marked changes in lining cell configuration as shown with both SEM and TEM consistently accompanied calcitonin administration.