Protein metabolism of the rat uterus during the oestrous cycle, pregnancy and pseudopregnancy, and as affected by an anti-implantation compounds, ICI 46,474.

Abstract

Incorporation of tritiated leucine into uterine protein was examined during the estrus cycle early pregnancy and pseudopregnancy. The effects of an antiimplantation compound ICI 46474 (trans-1-(rho-beta dimethylaminothoxyphenyl)-12 diphenyl but-1-ene) were also examined. No significant variation in the protein content of the uterine tissue occurred during the estrus cycle. There was a highly significant (p< .002) increase in the rate of incorporation of radioactive leucine into uterine protein during metestrus and diestrus. Incorporation of tritiated leucine into uterine protein showed a large increase on Days 3 and 4 of pseudopregnancy. .1 mg/kg ICI 46474 given on Day 2 reduced the size of the implantation sites measured on Day 9. A dose of .2 mg/kg inhibited implantation completely. In the group receiving .05 mg/kg ICI 46474 the radioactivity of the acid soluable pool decreased significantly (p< .05) as it also did in the control. The uptake of tritiated leucine was elevated in all groups on Day 3 followed by a decreased on Day 4. The decrease was greatest during treatment with .20 mg/kg.