FIGURE 3 .

Effects of butyrate on the tight junction assembly and AMPK activation in Caco-2 cell monolayers after calcium switch. (A) After incubation in a low-calcium medium for 16 h, cell monolayers were switched to a regular calcium medium alone or with 2 mmol/L of butyrate, or with 0.5 mmol/L of AICAR. Values are means + SE, n = 5. *Different from control at that time, P ≤ 0.05. B. Total cell lysates from untreated cells or those treated with 2 mmol/L of butyrate at indicated calcium-switch time points were subjected to immunoblotting for pAMPK, total AMPK, and actin with specific antibodies. (C) AMPK activity was expressed as the ratio of the phosphorylated form of the protein to total protein. Values are means + SE, n = 8. *Different from control at that time, P ≤ 0.05.