An isotopic study of oxalate excretion in sheep.
Intravenously injected 14C labelled oxalate was rapidly removed from the blood stream via the kidney in 2 sheep, 75% being cleared within 8 h. Mean daily urinary oxalate excretions over 5 days were 21-2 and 27-5 mg and the derived plasma oxalate concentrations were 52-6 and 74-4 mug/100 ml, respectively. Oxalate was both filtered and secreted by the renal tubule with oxalate/inulin ratios varying from 1-11 to 1-57 in 6 normal sheep. A large increase in calcium excretion induced by calcium borogluconate infusion over 5 days was accompanied by a small but consistent increase in urinary oxalate excretion relative to calcium. Oxalate in blood was to be found mainly in the plasma, there being a small (8%) proporation within erythrocytes. This is lower than that reported for man, and yet in its excretion of oxalate via the kidney the sheep appears to closely resemble man and dog.
D000818:Animals; D002118:Calcium / Q000378:metabolism; D004912:Erythrocytes / Q000032:analysis; D005260:Female; D005919:Glomerular Filtration Rate; D007668:Kidney / Q000378:metabolism; D010070:Oxalates / Q000097:blood / Q000378:metabolism* / Q000652:urine; D012756:Sheep / Q000097:blood / Q000378:metabolism* / Q000652:urine
D010070:Oxalates; D002118:Calcium