Page 53 - Fluid, Electrolyte, and Acid-Base Disorders in Small Animal Practice

42 APPLIED PHYSIOLOGY

which is found in the mitochondria of the proximal tubular 12. Dunn MJ. Nonsteroidal antiinflammatory drugs and renal
cells. Calcitriol interacts with its high-affinity receptor (the function. Annu Rev Med 1984;35:411.
vitamin D receptor [VDR]) in target tissues forming a 13. Ebert BL, Bunn HF. Regulation of the erythropoietin
gene. Blood 1999;94:1864–77.
ligand-activated transcription factor that travels to the
14. Eschbach JW, Egrie J, Downing M, et al. Correction of ane-
nucleus of the cell and interacts with specific DNA mia of end-stage renal disease with recombinant human
sequences in vitamin D-responsive genes. erythropoietin. N Engl J Med 1987;316:73–8.
The activity of the 1a-hydroxylase system is closely 15. Fenton RA. Essential role of vasopressin-regulated urea
transport processes in the mammalian kidney. Pflugers Arch
regulated by PTH, calcium, phosphate, and calcitriol itself,
2009;458:169–77.
which exerts negative feedback inhibition on 1a-hydroxy-
16. Fettman MJ, Allen TA, Wilke WL, et al. Single-injection
lase. Hypocalcemia and PTH stimulate calcitriol synthesis. method for evaluation of renal function with 14 C-inulin
3
There is an inverse relationship between calcium and H-tetraethylammonium bromide in dogs and cats.
concentrations and the activity of the 1a-hydroxylase Am J Vet Res 1985;46:482.
17. Finco DR. Simultaneous determination of phenolsul-
enzyme system that may arise directly or may be secondary
fonphthalein excretion and endogenous creatinine clearance
tochangesinthesecretionofPTHinresponsetoalterations in the normal dog. J Am Vet Med Assoc 1971;159:336.
in serum calcium concentration. Some evidence exists to 18. Finco DR, Barsanti JA. Mechanism of urinary excretion of
supportadirectsuppressiveeffectofcalciumon1a-hydrox- creatinine by the cat. Am J Vet Res 1982;43:2207.
4
ylase activity in proximal tubular cells. The 1a-hydroxylase 19. Finco DR, Brown SA, Crowell WA, et al. Exogenous creat-
inine clearance as a measure of glomerular filtration rate in
enzyme system is stimulated by hypophosphatemia and
dogs with reduced renal mass. Am J Vet Res 1991;52:1029.
inhibited by hyperphosphatemia. 20. Finco DR, Coulter DB, Barsanti JA. Simple, accurate
The major effects of 1,25-dihydroxycholecalciferol method for clinical estimation of glomerular filtration rate
(calcitriol) are increased intestinal absorption of calcium in the dog. Am J Vet Res 1981;42:1874.
and phosphate, a permissive effect on PTH-mediated 21. Finco DR, Duncan JR. Evaluation of blood urea nitrogen
bone resorption of calcium and phosphate, and negative and serum creatinine concentrations as indicators of renal
dysfunction: a study of 111 cases and a review of related lit-
feedback control on PTH synthesis and secretion by erature. J Am Vet Med Assoc 1976;168:593.
the parathyroid glands. The actions of vitamin D are 22. Finco DR, Tabaru H, Brown SA, et al. Endogenous creati-
discussed in more detail in Chapter 6. nine clearance measurement of glomerular filtration rate in
dogs. Am J Vet Res 1993;54:1575.
23. Fried W. Erythropoietin and erythropoiesis. Exp Hematol
2009;37:1007–15.
REFERENCES 24. Hardy RM, Osborne CA. Water deprivation test in the dog:
Maximal normal values. J Am Vet Med Assoc 1979;174:479.
1. Avison MJ, Gullans SR, Ogino T, et al. Measurement of 25. Jamison RJ. The renal concentrating mechanism. Kidney
Na-K coupling ratio of Na-K ATPase in rabbit proximal Int 1987;32(Suppl. 21):S43.
tubules. Am J Physiol 1987;253:C126. 26. Jamison RL, Maffly RH. The urinary concentrating mech-
2. Berliner RW. Mechanisms of urine concentration. Kidney anism. N Engl J Med 1976;295:1059.
Int 1982;22:202. 27. Keyes JL, Swanson RE. Dependence of glucose Tm on
3. Biber J, Hernando N, Forster I, et al. Regulation of phos- GFR and tubular volume. Am J Physiol 1971;221:1.
phate transport in proximal tubules. Pflugers Arch 28. King LG, Giger U, Diserens D, et al. Anemia of chronic
2009;458:39–52. renal failure in dogs. J Vet Intern Med 1992;6:264–70.
4. Bland R, Walker EA, Hughes SV, et al. Constitutive expres- 29. Kokko JP. The role of the collecting duct in urinary concen-
sion of 25-hydroxyvitamin D3-1 alpha-hydroxylase in a tration. Kidney Int 1987;31:606.
transformed human proximal tubule cell line: evidence 30. Kokko JP, Rector Jr FC. Countercurrent multiplication sys-
for direct regulation of vitamin D metabolism by calcium. tem without active transport in inner medulla. Kidney Int
Endocrinology 1999;140:2027–34. 1972;2:214.
5. Bovee KC, Joyce T. Clinical evaluation of glomerular func- 31. Koushanpour E, Kriz W. Renal physiology: principles,
tion: 24-hour creatinine clearance in dogs. J Am Vet Med structure, and function. New York: Springer-Verlag; 1986.
Assoc 1979;174:488. 32. Kruth SA, Cowgill LD. Renal glucose transport in the cat
6. Bro ¨er S. Amino acid transport across mammalian intestinal (abstract). Proc Am Coll Vet Intern Med 1982;78:1982.
and renal epithelia. Physiol Rev 2008;88:249–86. 33. Levitin H, Goodman A, Pigeon G, et al. Composition of
7. Brown SA. Determinants of glomerular ultrafiltration in the renal medulla during water diuresis. J Clin Invest
cats. Am J Vet Res 1993;54:970. 1962;41:1145.
8. Bulger RE. Composition of renal medullary tissue. Kidney 34. MacLeod JN, Tetreault JW, Lorschy KAS, et al. Expression
Int 1987;31:557. and bioactivity of recombinant canine erythropoietin. Am J
9. Chandhoke PS, Saidel CM, Knepper MA. Role of inner Vet Res 1998;59:1144–8.
medullary collecting duct NaCl transport in urinary 35. Maxwell PH, Ferguson DJP, Nicholls LG, et al. Sites of
concentration. Am J Physiol 1985;249:F688. erythropoietin production. Kidney Int 1997;51:393.
10. Clive DM, Stoff JS. Renal syndromes associated with nonste- 36. Navar LG, Bell PD, Crowell WA, et al. Evaluation of the
roidalantiinflammatorydrugs.NEnglJMed1984;310:563. single nephron glomerular filtration coefficient in the
11. Cowgill LD, James KM, Levy JK, et al. Use of recombinant dog. Kidney Int 1977;12:137.
human erythropoietin for the management of anemia in 37. O’Grady SM, Palfrey HC, Field M. Characteristics and
dogs and cats with renal failure. J Am Vet Med Assoc function of Na-K-2Cl cotransport in epithelial tissues.
1998;212:521–8. Am J Physiol 1987;253:C177.