Immunostaining of VSNL1 and KCNJ5 highlighted the increase in the zG in the pigs fed a 14-day low sodium diet. The thickness of the zG layer is shown as a percentage of the total thickness of the adrenal cortex. The average of 6 measurements for each adrenal is shown (Panel A and B). CYP11B immunostaining shows the expansion of the zG layer is complemented by an increase in aldosterone synthase-positive cells in pigs on a low sodium diet (Panel C) and immunostaining for Ki67, a marker of cell proliferation, shows a significant increase in Ki67-positive cells in the zG layer on a low versus high sodium diet (Panel D). Bars represent mean ± SEM (n=3 per group), a Mann-Whitney test was used to detect differences. Circles, high sodium; triangles, low sodium diet. *p<0.05, ***p<0.001.