INVESTIGATION OF THE EFFECTS OF HYPERTHYROIDISM ON RENAL-FUNCTION IN THE CAT

This study evaluated the effects of thyroxine on renal function in the cat, Baseline serum thyroxine (T-4) concentrations, clinicopathologic data (complete blood count [CBC], serum chemistry panel, urinalysis), and nuclear medicine determinations of glomerular filtration rate (GF R), effective renal plasma flow (ERPF), and effective renal blood flow (ERBF) were measured in 10 normal adult cats, Cats were then injected with thyroxine (T-4) (50 mu g/kg SQ) daily for 30 d to induce hyperth yroidism, Clinicopathologic and nuclear medicine studies were repeated at 30 d, Cats injected with thyroxine had significant increases in T- 4, GFR, and ERBF and significant declines in serum creatinine and bloo d urea nitrogen (BUN) values, Administration of high doses of exogenou s thyroxine to cats results in significant stimulation of renal functi on.