Fig. 5

Blood estrogen decreases after meals and activation of gastric acid secretion decreases gastric estrogen production in females. (a) and (b) Eight-week-old female rats in the metestrous phase were deprived of food for 12 h. (a) Rats were fed ND ad libitum for 30 min (from − 0.5 to 0 h, bars). Blood TG, FFA, glucose, and E2 levels in the tail vein were measured before (−0.5) and at 0, 1, 2, 3, 4, and 5 h after feeding (red). Data from ND-fed male rats in Fig. 1a were plotted for comparison (blue). (b) Rats were fed ND ad libitum for 30 min. Blood TG, FFA, glucose, and E2 levels in the tail vein and blood E2 levels in the portal vein were measured 2 h after feeding (blue). Fasted rats were used as control “pre-fed” rats (brown). (c) Comparison of blood E2 levels in the portal vein of male (Fig. 1d) and female rats. (d) Female rats aged 11 to 15 weeks in the metestrous phase were deprived of food for 4 h. Isolated gastric gland epithelia were cultured with testosterone (20 nM) and C12-FFA (500 µM), either alone or in the presence of gastrin (100 pg/ml), histamine (100 pg/ml), glucagon (40 pg/ml), GLP-1 (3 pg/ml), LPZ (1 nM), or insulin (100 pg/ml). Their relative E2 production levels, compared to those without hormones or LPZ, were determined. Data are represented as mean ± s.d. n = 8. (a–c) P values were determined by a two-sided Student’s t-test between the indicated data sets. (d) P values, compared to the control hormone-free samples, were determined by Steel’s multiple comparison test (**P < 0.005). Raw data and actual P values are provided in Supplementary Data 5.