Highest concentration of potassium is seen in- (AIIMS NOV 2009)
I. The concentration of K+ in pancreatic juice is same as plasma i.e. around 4.5 mEq/L. Q
II. Liver bile contains 5-6 mEq/L whereas Gall Bladder bile has 12 mEq/L. Q
III. In ileum the concentration rises due to exchange of potassium with Na+ (K+ absorption also occurs). It normally is around 10-12 mEq/L.
IV. As it reaches rectum the conc. of K+ rises to 75 mEq/L Qdue to colonic secretion of K+.
V. Normal stool K+ excretion is 5-10 mEq a day Qand volume is 100-200 grams.
VI. Saliva contains 25-30 mEq/L at low flow rate Q& 15-20 mEq/L at high flow rate
VII. So max conc. is seen in stool Q or in colon Q but maximum levels or secretion is seen in saliva Q (since volume secreted is 1.5 L/day Q as compared to 100-200 ml of stool)