Regulation of urinary phosphate excretion in camels

Urinary inorganic phosphorus (P) excretion was measured in 16 adult female non-pregnant, non-lactating daily watered camels. They were randomly divided into four groups of four animals. Groups 1, 2, and received either an i.v. infusion of phosphate or synthetic human parathyroid hormone (PTH) or PTH-related peptide (PTHrP), respectively. The fourth group was used as a control. Intravenous P loading induced a significant increase in phosphatemia and in P renal clearance. Both PTH and PTHrP increased calcemia and decreased phosphatemia. They had no significant effect on urinary calcium excretion, but they increased P renal clearance and phosphaturia. Thus, the regulation of urinary P excretion in normally watered camels looks similar to that already described in other ruminants.