FIGURE 2.

Impaired butyrate transport across the proximal colon epithelium in the SHR. A, Butyrate levels in the cecum, proximal and distal colon of adult WKY and SHR. Fecal samples were collected at indicated segments of the intestine, and subjected to HPLC for measurement of butyrate levels. One-way ANOVA was performed with Sidak’s multiple comparison test. *P < 0.05, ^†P < 0.01, ^‡P < 0.001. B, Decrease in butyrate levels in proximal colon relative to cecum of adult WKY and SHR. Unpaired t-test P = 0.1. C, Butyrate absorption in the proximal colon of adult WKY and SHR. Proximal colon was isolated from adult WKY and SHR and mounted in the Ussing chamber. Krebs buffer containing 40 mmol/L butyrate was applied on the apical side of the proximal colon. One hour following the incubation, butyrate levels in both apical and basolateral solutions were determined by LC-MS. “Used” butyrate represents the difference between total butyrate initially applied to the chamber and the butyrate levels in the apical and basolateral solutions. *P < 0.05 in unpaired t-test. D, Short circuit current measurements (Isc) show no difference in proximal colon ionic transport between WKY and SHR at baseline and upon addition of butyrate. The black arrow indicates addition of butyrate to the apical side of proximal colon