home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
The Arsenal Files 6
/
The Arsenal Files 6 (Arsenal Computer).ISO
/
health
/
med9603.zip
/
M9630334.TXT
< prev
next >
Wrap
Text File
|
1996-02-27
|
3KB
|
45 lines
Document 0334
DOCN M9630334
TI Oral absorption of anti-AIDS nucleoside analogues. 1. Intestinal
transport of didanosine in rat and rabbit preparations.
DT 9603
AU Sinko PJ; Hu P; Waclawski AP; Patel NR; Department of Pharmaceutics,
College of Pharmacy, Rutgers; University, Piscataway, NJ 08855, USA.
SO J Pharm Sci. 1995 Aug;84(8):959-65. Unique Identifier : AIDSLINE
MED/96010379
AB The intestinal transport of didanosine (ddl), a nucleoside analog used
in the treatment of human immunodeficiency virus (HIV) infection, was
characterized using in situ and in vitro techniques. The zero-trans
uptake of ddl in rat intestinal brush border membrane vesicles (BBMV)
was linear over the range of 1 microM to 50 mM, ruling out a significant
carrier-mediated absorption component. The lack of carrier-mediated
transport was confirmed in a second species (rabbit). In order to
quantitate the convective (Pconv) and diffusive (Pdiff) components of
ddl intestinal permeability, the steady state wall permeability (P*w)
was determined using an established perfusion technique in rats. Even
though baseline P*w (pH 6.5, 290 mosm/kg, no modulator) and fluid
absorption results were similar to those of furosemide, the ratios
(ddl:furosemide) of Pdiff and phi, the sieving coefficient, were 0.31:1
and 1.70:1, respectively, demonstrating that ddl's Pdiff is low and
Pconv is high relative to furosemide's, suggesting significant
paracellular absorption of ddl. The apparent diffusive absorptive
clearances (P'app) of ddl and furosemide were determined in BBMV, which
lack functional tight junctions, and the ratios (ddl:furosemide) of
P'app in rat and rabbit were 0.23:1 and 0.24:1, respectively. The BBMV
results demonstrate that the majority of ddl intestinal transport does
not occur by passive membrane diffusion, confirming the single pass
intestinal perfusion (SPIP) findings. The results of these studies
suggest that ddl is transported by nonfacilitated membrane and
paracellular diffusion with paracellular transport being responsible for
the majority of ddl absorption from the intestine.
DE Animal Antiviral Agents/*PHARMACOKINETICS Biological Availability
Didanosine/*PHARMACOKINETICS Diffusion Diuretics,
Sulfamyl/PHARMACOLOGY Female Furosemide/PHARMACOLOGY Human HIV/*DRUG
EFFECTS In Vitro Intestinal Absorption Male Microvilli/METABOLISM
Permeability Rabbits Rats Rats, Sprague-Dawley Support, Non-U.S.
Gov't Support, U.S. Gov't, P.H.S. JOURNAL ARTICLE
SOURCE: National Library of Medicine. NOTICE: This material may be
protected by Copyright Law (Title 17, U.S.Code).