title: Variations of intestinal calcium absorption in adult frogs (Rana esculenta). Effect of lysine.
abstract: Intestinal calcium absorption was investigated in an adult frog (Rana esculenta) by injecting a CaCl2 solution containing 45Ca into the lumen. The 45Ca absorption coefficient in the proximal loop was higher than in the distal loop, only when the CaCl2 solution was left for 4 h. This coefficient increased both in the proximal and distal loops when a 4-h treatment was substituted for a 1-h treatment. The coefficient increased in the whole intestine during the first 2 h of treatment (1 h: 21%; 2 h: 55%) and remained stable afterwards in our experimental conditions. The intestinal calcium absorption increase occurred early in the presence of L-lysine (100 mM), since the coefficient already reached its maximum value (52%) after a 1-h treatment.
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism*; D007408:Intestinal Absorption / Q000187:drug effects*; D008239:Lysine / Q000494:pharmacology*; D011893:Rana esculenta
chemical_list: D008239:Lysine; D002118:Calcium