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

Intravenous injection of 6.7-60 micrograms of 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 mumol 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.