K. Sawai et al., RENAL DISPOSITION CHARACTERISTICS OF OLIGONUCLEOTIDES MODIFIED AT TERMINAL LINKAGES IN THE PERFUSED RAT-KIDNEY, Antisense research and development, 5(4), 1995, pp. 279-287
Citations number
56
Categorie Soggetti
Medicine, Research & Experimental","Biothechnology & Applied Migrobiology
To clarify the renal disposition characteristics of oligonucleotides a
t the organ level, the renal handling of model end-capped oligonucleot
ides, 3'-methoxyethylamine 5'-biotin-decathymidylic acid containing ph
osphoramidate modifications at 3'- and 5'-terminal internucleoside lin
kages (T-10) and its phosphorothioate (Ts(10)), were studied in the pe
rfused rat kidney. In a single-pass indicator dilution experiment, ven
ous outflow and urinary excretion patterns and tissue accumulation of
radiolabeled oligonucleotides were evaluated under filtering or nonfil
tering conditions. No significant binding to bovine serum albumin (BSA
) in the perfusate was observed for T-10, whereas more than 90% of Ts(
10) bound to BSA. The steady-state distribution volume of T-10 calcula
ted from the venous outflow pattern was larger than that of inulin, wh
ich corresponds to the extracellular volume of the kidney, whereas the
distribution volume of Ts(10) was larger than that of BSA (the intrav
ascular volume). These results suggested their interaction with the va
scular wall, Rapid urinary excretion was observed for T-10, similar to
inulin used as a marker of golmerular filtration rate. On the other h
and, urinary excretion of Ts(10) was greatly restricted due to its hig
h binding ability (>90%) to BSA in the perfusate. A significant amount
of T-10 and Ts(10) was accumulated in the kidney (T-10, 1.8% of injec
ted dose; Ts(10), 1.3%) compared with inulin (0.2%) and BSA (<0.1%). T
he accumulation of these oligonucleotides was ascribed to both tubular
reabsorption and uptake from the capillary side. In addition, the upt
ake of T-10 from the capillary side was significantly inhibited by sim
ultaneous injection of dextran sulfate, suggesting that the oligonucle
otide was taken up as an anionic molecule. These findings will be usef
ul information for the development of delivery systems for antisense o
ligonucleotides.