PT - JOURNAL ARTICLE AU - Martin, U AU - Doerge, L AU - Stegmeier, K AU - Müller-Beckmann, B TI - Influence of the degree of renal dysfunction on the pharmacokinetic properties of the novel recombinant plasminogen activator reteplase in rats. DP - 1996 Mar 01 TA - Drug Metabolism and Disposition PG - 288--292 VI - 24 IP - 3 4099 - http://dmd.aspetjournals.org/content/24/3/288.short 4100 - http://dmd.aspetjournals.org/content/24/3/288.full SO - Drug Metab Dispos1996 Mar 01; 24 AB - Reteplase (drug code: BM 06.022) is an unglycosylated recombinant plasminogen activator variant derived from human tissue-type plasminogen activator. The main metabolic organs of reteplase are the kidneys, liver, and blood, whereas human tissue-type plasminogen activator is predominantly cleared by the liver. Recent studies showed that reteplase plasma concentrations were significantly increased in severe acute renal failure. The purpose of the present study was to evaluate whether the degree of renal failure influences the pharmacokinetic properties of reteplase. Subacute renal failure in rats was induced by bilateral 1-hr clamping of the renal arteries and recovery for 3 or 6 days. Acute renal failure was induced by bilateral surgical nephrectomy. Renal function was assessed by inulin clearance. The plasma concentration of functionally active reteplase was measured by an indirect spectrophotometric assay. Reteplase was administered as a double-bolus intravenous injection of 140 + 140 kU/kg, 30 min apart. In comparison with sham surgery, 1-hr clamping plus recovery for 6 days had the least effect on inulin clearance, followed by clamping and recovery for 3 days and bilateral nephrectomy (20.2 +/- 1.8 vs. 13.0 +/- 1.3, 8.3 +/- 0.8, and 3.1 +/- 0.2 ml center dot min-1 center dot kg-1, p < 0.01). Total plasma clearance of reteplase was significantly reduced, compared with sham surgery after 1-hr clamping plus 3-day recovery and bilateral nephrectomy (3.65 +/- 0.26 vs. 2.6 +/- 0.23 and 2.18 +/- 0.14 ml center dot min-1 center dot kg-1, p < 0.05 and p < 0.01, respectively), but not after 1-hr clamping plus 6-day recovery (3.33 +/- 0.34 ml center dot min-1 center dot kg-1, NS vs. sham surgery). There was a significant (p < 0.0001) linear correlation (r = 0.713) between the decrease of inulin clearance and the decrease of reteplase clearance. These data indicate that slight impairment of renal function does not significantly influence pharmacokinetic properties of reteplase, whereas severe renal dysfunction does.