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PHOSPHATE EXCRETION AND REABSORPTION IN THE CONSCIOUS DOG
Author(s) -
Summerill R. A.,
Lee K. E.
Publication year - 1985
Publication title -
quarterly journal of experimental physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.925
H-Index - 101
eISSN - 1469-445X
pISSN - 0144-8757
DOI - 10.1113/expphysiol.1985.sp002900
Subject(s) - reabsorption , chemistry , endocrinology , medicine , excretion , renal physiology , renal function , creatinine , phosphate , renal glucose reabsorption , kidney , biochemistry , biology , diabetes mellitus , type 2 diabetes mellitus
When normal conscious dogs were given small doses of (NH 4 ) 2 HPO 4 by stomach tube to increase their plasma PO 4 , the rate of excretion of PO 4 increased without change in creatinine clearance. After eating meat, increased PO 4 excretion was accompanied by increase in both creatinine caearance and plasma PO 4 . The calculated rate of tubular reabsorption of PO 4 did not change significantly after (NH 4 ) 2 HPO 4 administration, but there was a significant increase in PO 4 reabsorption after meat; in comparison there was no change in SO 4 reabsorption. Similarly, administration of certain amino acids, which caused an increase in creatinine clearance, also caused a significant increase in PO 4 reabsorption. Administration of SO 4 with PO 4 had no significant effect on PO 4 reabsorption. It appears from the results, that PO 4 has an apparent tubular maximum rate of reabsorption ( T m ) when plasma PO 4 alone is varied; but this T m is not a real maximum because PO 4 reabsorption increases above this value after the administration of meat or amino acids, both of which cause an increase in glomerular filtration rate. There is no evidence to suggest that there is any inhibition of PO 4 reabsorption by SO 4 or amino acids.