• Open Access

Effect of Experimental Hypothyroidism on Glomerular Filtration Rate and Plasma Creatinine Concentration in Dogs

Authors

  • D.L. Panciera,

    1. Department of Small Animal Clinical Sciences, Virginia-Maryland Regional College of Veterinary Medicine, Virginia Tech, Blacksburg, VA
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  • H.P. Lefebvre

    1. Department of Clinical Sciences and UMR 181 INRA, ENVT Experimental Physiopathology and Toxicology, National Veterinary School, Toulouse, France
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  • This study was performed at the Virginia-Maryland Regional College of Veterinary Medicine, Virginia Tech, Blacksburg, VA. Reported in part as an abstract at the 2008 ECVIM-CA Congress, Ghent, Belgium.

Corresponding author: David Panciera, Department of Small Animal Clinical Sciences, Virginia-Maryland Regional College of Veterinary Medicine, Virginia Tech, Blacksburg, VA; e-mail: panciera@vt.edu.

Abstract

Background: Hypothyroidism affects renal function in a manner opposite the effects of hyperthyroidism.

Objective: To evaluate the effects of experimentally induced hypothyroidism on glomerular filtration rate (GFR) and basal plasma creatinine concentration in dogs.

Animals: Sixteen anestrous, female dogs.

Methods: Hypothyroidism was induced by administration of 131I in 8 dogs, and 8 healthy euthyroid dogs acted as controls. Exogenous plasma creatinine clearance (an estimate of GFR) was measured in all dogs before (control period) and 43–50 weeks after induction of hypothyroidism (posttreatment period). Other pharmacokinetic parameters of creatinine were also determined.

Results: No significant difference was observed for basal plasma creatinine concentration and creatinine clearance between control and hypothyroid dogs in the control period. In the posttreatment period, mean ± SD creatinine clearance in the hypothyroid group (2.13 ± 0.48 mL/min/kg) was lower (P < .001) than that of the control group (3.20 ± 0.42 mL/kg/min). Nevertheless, basal plasma creatinine concentrations were not significantly different between the hypothyroid and control groups (0.74 ± 0.18 versus 0.70 ± 0.08 mg/dL, respectively) because endogenous production of creatinine was decreased in hypothyroid dogs (22 ± 3 versus 32 ± 5 mg/kg/d, P=.001).

Conclusion and Clinical Importance: Hypothyroidism causes a substantial decrease in GFR without altering plasma creatinine concentrations, indicating that GFR evaluation is needed to identify renal dysfunction in such patients.

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