Effects of D-Asp on LH and cGMP synthesis in isolated rat pituitary glands. Pituitary glands were incubated at 37°C for 60 min in a medium with Na-D-aspartate 0.1 or 1.0 mM and then LH and cGMP levels were determined in the total gland homogenate plus medium. The left panel shows that the increase of LH (LH synthesis) due to the action of the two concentrations of D-Asp versus the control (pituitary incubated without D-Asp): A, B (p < 0.001); a, b (p < 0.02). The right panel shows the total concentration of cGMP determined in the same samples as above obtained (cGMP synthesis): A, B and C, D(p < 0.001). Results are the mean ± SEM obtained from 5 individual experiments. Asterisks indicate that the difference in value between treated rats and control rats was significant at p < 0.0001, evaluated by one-way ANOVA.