Hypercalcaemic responses to 16,16-dimethyl prostaglandin E2, a stable prostaglandin E2 analogue in chicks

Abstract

Intravenous injection of 6·7–60 μg of a stable prostaglandin E₂ analogue, 16,16-dimethyl prostaglandin E₂, into 10-day-old chicks caused profound, long-lasting hypercalcaemia. Simultaneous i.v. loading with 50 μmol Ca/bird enhanced the peak response. The responses were accompanied by sedation and lowered skin temperature. Use of acute (simultaneous) ⁴⁵Ca labelling indicated that the hypercalcaemic responses were due primarily to inhibition of Ca exit from extracellular fluid pools, while chronic (6-day) ⁴⁵Ca labelling indicated a slower but distinct increase in mobilization of bone Ca pools.