Effects of RYGB, BMT and sham surgery on gut hormone co-localization in islets 8 weeks post-experimental intervention.

(A) Representative islet images showing PYY (red) with glucagon & somatostatin (green), GLP-1 (red) with glucagon (green). Nuclei are demonstrated using DAPI staining (blue). Quantification of co-localization of PYY with (B) glucagon and (C) somatostatin, and (D) GLP-1 with glucagon are also shown. Arrows indicate cells that are positive for both PYY and glucagon or somatostatin, and GLP-1 with glucagon. Normal SD rats are included for comparison. Values are mean ± SEM (n = 4) with statistical significance evaluated using one-way ANOVA. *p<0.05, **p<0.01, ***p<0.001 compared to sham rats. Analyses carried out on 60–80 islets per group.</p

Effects of RYGB, BMT and sham surgery on PYY positive cell distribution in the ileum of ZDSD rat intestine.

(A) Representative images showing PYY (green); arrows indicate PYY positive cells. Nuclei are demonstrated using DAPI staining (blue). (B) number of PYY positive cells per mm2 of ileum, (C) number of PYY positive cells per mm2 of crypt and (D) number of PYY positive cells per mm2 of villi analyzed in ileum sections. Normal SD rats are included for comparison. Values are mean ± SEM (n = 4) with statistical significance evaluated using one-way ANOVA. *p<0.05, ***p<0.001 compared to sham. Analyses carried out on ~200 cells per group.</p

Summary of results and their possible biological significance after RYGB surgery.

Summary of results and their possible biological significance after RYGB surgery.</p

Effects of RYGB, BMT and sham surgery on body weight and non-fasting plasma glucose of ZDSD rats.

(A) % Weight change at 8-weeks post-intervention (B) Plasma glucose at 8-weeks post-intervention. Normal SD rats are included for comparison. Values are mean ± SEM (n = 4) with statistical significance evaluated using one-way ANOVA. *p<0.05, **p<0.01, ***p<0.001 compared to sham operated rats.</p

Effects of RYGB, BMT and sham surgery on islet morphology and architecture 8 weeks post-experimental intervention in ZDSD rats.

(A) Size distribution (% of islets analyzed), (B) islet circularity–reports degree of roundness where 1.0 corresponds to a perfect circle, (C) islet area, (D) beta- cell area, (E) alpha-cell area, (F) beta- cell / alpha -cell ratio (area), (G) percentage of beta- cells (per total islet cells), (H) percentage of alpha-cells (per total islet cells), (I) PYY cell area and (J) delta-cell area, were determined using the ‘closed polygon’ and ‘multi-point’ tool in Olympus CellˆF analysis software. Normal SD rats are included for comparison. (K) Representative images of islets showing insulin (red), glucagon (green). Nuclei are demonstrated using DAPI staining (blue). Values are mean ± SEM (n = 4) with statistical significance evaluated using one-way ANOVA. *p<0.05, **p<0.01, ***p<0.001 compared to sham rats. Analyses carried out on 60–80 islets per group.</p

Effects of RYGB, BMT and sham surgery on GLP-1 positive cell distribution in the ileum of ZDSD rat intestine.

(A) Representative images showing GLP-1 (green); arrows indicate GLP-1 positive cells. Nuclei are demonstrated using DAPI staining (blue). (B) number of GLP-1 positive cells per mm2 of ileum, (C) number of GLP-1 positive cells per mm2 of crypt and (D) number of GLP-1 positive cells per mm2 of villi analyzed in ileum sections. Normal SD rats are included for comparison. Values are mean ± SEM (n = 4) with statistical significance evaluated using one-way ANOVA. **p<0.01 compared to sham rats. Analyses carried out on ~200 cells per group.</p

Effects of RYGB, BMT and sham surgery on ileal hormone content in ZDSD rats.

(A) Ileal PYY content (pg/mg protein), (B) ileal GLP-1 content (nmol/mg protein) and (C) ileal GIP content (pg/mg protein). Normal SD rats are included for comparison. Values are mean ± SEM (n = 4) with statistical significance evaluated using one-way ANOVA. *p<0.05, ***p<0.001 compared to sham.</p

Effects of RYGB, BMT and sham surgery on beta- cell proliferation and apoptosis in ZDSD rats.

(A) Representative images showing insulin (red) with Ki-67 TUNEL (green). Nuclei are demonstrated using DAPI staining (blue). (B) beta- cell proliferation frequency expressed as a percentage of beta- cells analyzed (C) beta- cell apoptosis frequency expressed as a percentage of beta- cells analyzed. Normal SD rats are included for comparison. Arrows indicate TUNEL and Ki-67 positive cells. Values are mean ± SEM (n = 4) with statistical significance evaluated using one-way ANOVA. *p<0.05, ***p<0.001 compared to sham rats. Analyses carried out on 60–80 islets per group.</p

Effects of RYGB, BMT and sham surgery on GIP positive cell distribution in the ileum of ZDSD rats.

(A) Representative images showing GIP (green); arrows indicate GIP positive cells. Nuclei are demonstrated using DAPI staining (blue). (B) number of GIP positive cells per mm2 of ileum, (C) number of GIP positive cells per mm2 of crypt and (D) number of GIP positive cells per mm2 of villi analyzed in ileum sections. Normal SD rats are included for comparison. Values are mean ± SEM (n = 4) with statistical significance evaluated using one-way ANOVA. *p<0.05 compared to sham rats. Analyses carried out on ~200 cells per group.</p

Target, host and source of primary and secondary antibodies employed for immunofluorescent islet histology studies.

Target, host and source of primary and secondary antibodies employed for immunofluorescent islet histology studies.</p