Summary
The metabolism of MnDPDP (manganese(II)N,N′-dipyridoxylethylenediamine-N,N′-diacetate-5,5′-bis(phosphate) was studied in dogs after intravenous infusion for 12.5 min with either 10, 30 or 100 μmol MnDPDP/kg b.w. HPLC analyses of plasma samples obtained 1, 5 and 30 min after the end of infusion revealed that MnDPDP was rapidly dephosphorylated to MnDPMP (manganese(II)N,N′-dipyridoxylethylenediamine-N,N′-diacetate-5-phosphate) and MnPLED (manganese(II)N,N′-dipyridoxylethylenediamine-N,N′-diacetate), with simultaneous transmetallation to the corresponding zinc metabolites ZnDPDP, ZnDPMP and ZnPLED. In the low-dose group, the parent compound MnDPDP was present at the lowest concentration compared to the metabolites at the first sampling time point, 1 min after the end of infusion, whereas MnPLED was the main metabolite. At 30 min post-infusion ZnPLED was the main metabolite. The medium- and high-dose groups showed a similar metabolic pattern. In the high-dose group, MnPLED was the main metabolite at all sampling time points. The estimated plasma half-life of total ligand was 20 min, and it was dose-independent with an apparent volume of distribution of 0.2 l/kg. The rate of dephosphorylation was similar to the rate of transmetallation, and both were dose-independent. However, calculations of the total Mn and Zn ligands indicated that the apparent plasma elimination was dose-dependant. The half-life for total Mn ligands which is a combination of both metabolism and elimination, were 10 and 20 min at 10 and 100 μmol/kg, respectively. The half-life for total Zn ligands which is the half-life for rate of formation of Zn ligands, were 40 and 65 min at 10 and 100 μmol/kg, respectively. No sex differences in metabolic pattern were observed in any of the three dosage groups.
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Normann P.T., Hals P-A. (1996): In vivo stability and excretion of gadodiamide (GdDTPA-BMA), a hydrophilic gadolinium complex used as a contrast enhancing agent for magnetic resonance imaging. Eur. J. Drug Metab. Pharmacokinet., 20, 307–313.
Weinmann H.J., Laniado M., Mutzel W. (1984): Pharmacokinetics of Gd-DTPA dimeglumine after intravenous injection into healthy volunteers. Physiol. Chem. Phys., 16, 167–172.
McLachlan S.J., Eaton S., Desimone D.N. (1992): Pharmacokinetic behavior of gadoteridol injection. Invest. Radiol., 27 (suppl. 1), 12–15.
Elizondo G., Fretz C.J., Stark D.D. et al. (1991): Preclinical evaluation of MnDPDP: new paramagnetic hepatobiliary contrast agent for MR imaging. Radiology, 178, 73–78.
Lim K.O., Stark D.D., Leese P.T., Pfefferbaum A., Rocklage S.M., Quay S.C. (1991): Hepatobiliary MR imaging: first human experience with MnDPDP. Radiology, 178, 79–82.
Rocklage S.M., Cacheris W.P., Quay S.C., Hahn F.E., Raymond K.N. (1989): Manganese(II) N,N′-dipyridoxylethylenediamine-N,N′-diacetate 5,5′-bis(phosphate). Synthesis and characterization of a paramagnetic chelate for magnetic resonance imaging enhancement. Inorg. Chem., 28, 477–485.
Rofsky N.M., Weinreb J.C., Bernardino M.E., Young S.W., Lee J.K.T., Noz M.E. (1993): Hepatocellular tumours: characterization with MnDPDP — enhanced MR imaging. Radiology, 188, 53–59.
Wolf G.L., Baum L. (1983): Cardiovascular toxicity and tissue proton T1 response to manganese injection in the dog and rabbit. Am. J. Radiol., 141, 193–197.
Jynge P., Brurok H., Asplund A. et al. (1995): Cardiovascular safety of MnDPDP: experience from ex vivo and in vivo animal experiments. In: Rinck P.A., Muller R.N. (Eds) New Developments in Contrast Agent Research. Mons, Belgium: Eur. Magn. Reson. Forum, 83–103.
Toft K.G., Kindberg G.M., Skotland T. (1997): Mangafodipir trisodium, a new contrast medium for magnetic resonance imaging: in vitro metabolism and protein binding studies in human blood. J. Pharm. Biomed. Anal., In press.
Grant D., Zech K., Holtz E. (1994): Biodistribution and in vivo stability of manganese dipyridoxyl diphosphate in relation to imaging efficacy. Invest. Radiol., 29 (suppl. 2), S249-S250.
Toft K.G., Friisk G.A., Skotland T. (1997): Mangafodipir trisodium, a new contrast medium for magnetic resonance imaging: detection and quantitation of the active compound and metabolites in human plasma by high performance liquid chromatography. J. Pharm. Biomed. Anal., In press.
Parisi A.F., Vallee B.L. (1970): Isolation of a zinc α2-macroglobulin from human serum. Biochemistry, 9, 2421–2426.
Normann P.T., Hustvedt S.O., Storflor H., Hals P-A. (1995): Preclinical safety and pharmacokinetic profile of gadodiamide injection. Clin. MRI, 5, 95–101.
Okazaki O., Kurata T., Yoshioka N., Hakusui H. (1996): Pharmacokinetics and stability of caldiamide sodium in rats. Arzneimittelforschung., 46, 79–83.
Toft K.G., Hustvedt S.O., Grant D. et al. (1997): Metabolism and pharmacokinetics of mangafodipir trisodium (MnDPDP) in man. Acta Radiol., In press.
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Toft, K.G., Hustvedt, S.O., Grant, D. et al. Metabolism of mangafodipir trisodium (MnDPDP), a new contrast medium for magnetic resonance imaging, in beagle dogs. European Journal of Drug Metabolism and Pharmacokinetics 22, 65–72 (1997). https://doi.org/10.1007/BF03189786
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DOI: https://doi.org/10.1007/BF03189786