Fig. 11. The effect of protein kinase A (PKA) antagonists on dopamine-induced glycoprotein secretion by the albumen glands of H. duryi. Albumen glands were preincubated with either 1 mmol l^-1 Rp-cAMP (A) or 10 µmol l^-1 H-89 (B) for 60 min and then dopamine (10 µmol l^-1) + Rp-cAMP or dopamine + H-89 were added to the albumen glands for an additional 20 min. Neither PKA antagonist had an affect on basal protein secretion nor did they suppress dopamine-stimulated protein secretion by the albumen glands. Abbreviations: CON, control; DA, dopamine; DA+Rp, dopamine + Rp-cAMP; H-89+DA, dopamine + H-89. Bars represent the mean ± S.E.M. of 6 samples (^*P<0.05, Tukey test).