Stimulation of α receptors leads to:

  Vasoconstriction

decrease in gut motility uterus contraction

decrease in pancreatic exocrine secretion

Cholera toxin: activates G protein, which activates adenylate cyclase. Elevated cAMP results in unrestricted chloride secretion from villous crypts.

Iron is absorbed in upper small intestine. Iron absorption is increased with ascorbic acid. The sulfate form contains more elemental iron per dosage unit than gluconate.