45Ca uptake in tooth germs: effects of parathormone, calcitonin and propranolol.

Tooth germs harvested from 6-day-old rats were incubated in a 45Ca-containing medium for 6 hours. The addition of PTH consistently stimulated the increase in 45Ca uptake, while calcitonin significantly reduced both the PTH-stimulated incorporation and the spontaneous one. Dibutyrul CAMP (3.5 mM) had no effects. Propranolol significantly inhibited the spontaneous and stimulated 45Ca uptake. Results obtained support the concept that the two hormones have a clear influence on calcium entering the tooth germs in full calcification process probably by early membrane effect.