PMID- 10063720
OWN - NLM
STAT- MEDLINE
DCOM- 19990316
LR  - 20181201
IS  - 0578-1337 (Print)
IS  - 0578-1337 (Linking)
VI  - 62
IP  - 2
DP  - 1999 Feb
TI  - Inhibitory effects of Woodward's reagent K on carrier-mediated anion transport in 
      rabbit intestinal brush border membrane vesicles.
PG  - 98-106
AB  - BACKGROUND: Woodward's reagent K (N-ethyl-5-phenylisoxazolium 3'-sulfonate) is a 
      negatively charged reagent that covalently and irreversibly modifies 
      carboxyl-containing amino acid residues. Under conditions of an outwardly 
      directed hydroxide (OH.) gradient (pHin > pHout), folate uptake by jejunal brush 
      border membrane (BBM) vesicles is mediated by a folate:OH. exchanger or a 
      phenomenologically indistinguishable proton (H+):folate cotransporter. Under 
      these pH conditions, Woodward's reagent K rapidly inhibits folate uptake in a 
      pH-, temperature- and concentration-dependent manner. METHODS: Rabbit BBM 
      vesicles were prepared using the divalent cation precipitation method. Vesicle 
      uptake of 3H-folate was measured by a rapid filtration technique. Radioactivity 
      was gauged using a liquid scintillation counter. RESULTS: The initial rate of OH. 
      gradient-stimulated folate uptake remained linear in the presence or absence of 
      Woodward's reagent K, suggesting that Woodward's reagent K inhibition is not 
      secondary to more rapid dissipation of the transmembrane pH gradient. Woodward's 
      reagent K also inhibited other modes of transport mediated by the folate carrier, 
      3H-folate:folate exchanger, ileal sulfate (SO)4(2):OH. exchanger, but neither 
      sodium (Na+):glucose, Na+:SO4(2.) nor Na(+):alanine cotransporters, were 
      inhibited by 3 mM Woodward's reagent K. CONCLUSIONS: The inhibition of intestinal 
      anion exchangers by Woodward's reagent K suggests a critical role for carboxyl 
      group--containing amino acids in these transport processes.
FAU - Tam, T N
AU  - Tam TN
AD  - Department of Medicine, Veterans General Hospital-Taipei, Taiwan, ROC.
FAU - Schron, C M
AU  - Schron CM
LA  - eng
PT  - Journal Article
PL  - China (Republic : 1949- )
TA  - Zhonghua Yi Xue Za Zhi (Taipei)
JT  - Zhonghua yi xue za zhi = Chinese medical journal; Free China ed
JID - 0005327
RN  - 0 (Isoxazoles)
RN  - 3BN309R76H (N-ethyl-5-phenylisoxazolium-3'-sulfonate)
RN  - 935E97BOY8 (Folic Acid)
RN  - Q1O6DSW23R (4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid)
SB  - IM
MH  - 4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid/pharmacology
MH  - Animals
MH  - Folic Acid/*metabolism
MH  - Hydrogen-Ion Concentration
MH  - Intestinal Mucosa/metabolism
MH  - Intestines/*drug effects/ultrastructure
MH  - Ion Transport/drug effects
MH  - Isoxazoles/*pharmacology
MH  - Male
MH  - Microvilli/drug effects/metabolism
MH  - Rabbits
MH  - Temperature
EDAT- 1999/03/04 00:00
MHDA- 1999/03/04 00:01
CRDT- 1999/03/04 00:00
PHST- 1999/03/04 00:00 [pubmed]
PHST- 1999/03/04 00:01 [medline]
PHST- 1999/03/04 00:00 [entrez]
PST - ppublish
SO  - Zhonghua Yi Xue Za Zhi (Taipei). 1999 Feb;62(2):98-106.