[Effect of tyrosine on progesterone production by perifused rat large and small corpus luteal cells].

The effect of tyrosine on progesterone production by rat large and small luteal cells was studied by perifusion method. The large and small luteal cells were separated by sucrose density gradient centrifugation. After pre-perifusion for 1 h the effluent from the perifused large or small cells was separately collected at 10 min intervals by a fraction collector. Progesterone content of each sample was measured by RIA. Results showed that the basal progesterone production by large luteal cells was 2-fold more than that of the small ones. However, the suppressive effect of tyrosine on hCG- induced progesterone production was more pronounced in small luteal cells. These differences may be due to the fact that small luteal cells uptake more 3H- tyrosine.