Effect of dibutyryl cyclic AMP and oestradiol on incorporation of [3H]leucine into the proteins of luminal fluid of the rat uterus.

An injection of 12-5 nmol dibutyryl cyclic AMP (dbcAMP) into each uterine horn of ovariectomized rats maintained on progesterone alone, enhanced incorporation of [3H]leucine into uterine luminal proteins. A value of 11-73 X 10(3) c.p.m. [3H]leucine incorporated/rat was found after injection of dbcAMP compared with 3-69 X 10(3) c.p.m./rat after injection of saline. An injection of 1-0 microgram oestradiol, in contrast, gave 58-05 X 10(3) c.p.m./rat. Electrophoretic analysis showed that the radioactively labelled proteins found after an injection of dbcAMP or oestradiol were qualitatively similar to those detected on day 5 of pregnancy, the day of blastocyst implantation. The nucleotide thus apparently elicits a uterine response similar to that observed after an injection of oestradiol.