Ullrich, Karl J. published the artcileLuminal transport step of para-aminohippurate (PAH). Transport from PAH-loaded proximal tubular cells into the tubular lumen of the rat kidney in vivo, COA of Formula: C13H8Cl2O4S, the main research area is luminal transport aminohippurate rat kidney; benzoate transport inhibition aminohippurate lumen kidney; uricosuric compound transport inhibition aminohippurate kidney.
Proximal tubular cells were loaded for 10 s with [3H]para-aminohippurate ([3H]PAH) by microperfusing the peritubular capillaries with Ringer solution containing 0.05 mmol/l PAH. Immediately thereafter [3H]PAH influx from cells into a column of equilibrium solution injected into the oil-filled tubular lumen was measured by re-aspirating the fluid after 1-10 s of contact time. The rise of luminal PAH concentration within 2 s of contact time was almost linear, reaching a luminal / capillary concentration ratio of 1.6 after 2 s and of 3.2 after 5 s. The 2-s PAH concentration ratio was not changed when different maneuvers were applied to depolarize proximal tubular cells. Also, the 2-s PAH concentration ratio was not influenced by varying the luminal pH from 6.0 to 8.0 or the luminal Cl- concentration from zero to 134 mmol/l or when either 5 mmol/l urate or 25 mmol/l lactate was in the luminal perfusate. A decrease in the 2-s PAH concentration ratio, i.e. trans-inhibition, was observed when 25 or 50 mmol/l HCO3-(-50%) was in the luminal perfusate. Trans-inhibition was also seen with 5 mmol/l of the following substituted benzoates: 2-hydroxybenzoate (-58%), 2-methoxybenzoate (-46%), 2-hydroxybenzoate acetyl ester (-36%), 2-hydroxy-3,5-dinitrobenzoate (-48%), 3,5-dichlorobenzoate (-49%), and 2,3,5-trichlorobenzoate (-45%). No effect was seen with benzoate, 3-hydroxybenzoate, 2-chlorobenzoate, 2-nitrobenzoate, 2,5-dinitrobenzoate, 3-sulfamoylbenzoate and 4-sulfamoylbenzoate. However, analogs of the latter 2 compounds possessing 2 addnl. side groups, such as furosemide and piretanide, or a hydrophobic moiety, such as probenecid, were inhibitory (by -62, -41 and -49% resp.). Phenoxyacetate had no effect; however, it inhibited if in addition it had 3 chloro groups, as in 2,4,5-trichlorophenoxyacetate (-71%) or a hydrophobic carbamoyl side group, as in mersalylic acid (salyrgan, -75%). Benzene-sulfonate trans-inhibited (-33%), as did phenolsulfonphthalein (phenol red, -39%) and sulfofluorescein (-55%). However, the trans-inhibitory effect of the corresponding carboxy compounds was absent (phenolphthalein) or weaker (fluorescein, -42%). The trans-inhibitory effect of the uricosurics ethacrynic acid (-53%), tienilic acid (-55%) indacrinone (-72%) and benzbromarone (-42%) could be attributed to 2 chloro or bromo side groups on the benzene ring. Other trans-inhibiting uricosuric substances were indomethacin (-42%), sulfinpyrazone (-38%), losartan (-80%) its metabolite EXP 3174 (-55%), and AA 193 (-65%). These organic acids, with pKa values between 2.8 and 4.9, possess chloro and sulfin groups, as well as heterocyclic 5-ring and hydrophobic ring or chain areas. No significant effect was seen with 5 mmol/l PAH, 2-oxo-glutarate, DIDS, cGMP, prostaglandin E2, cortisol, benzylamiloride, pyrazinoic acid, and 25 mmol/l lactate. Our data indicate that in situ the secretory luminal PAH transport proceeds in a nonrheogenic fashion, per exclusionem by anion exchange. The observed trans-inhibition of PAH secretion seems to correlate with the affinity for the luminal PAH transporter and, for uricosuric substances, with their uricosuric potency.
Pfluegers Archiv published new progress about Biological transport. 40180-04-9 belongs to class benzothiophene, name is 2-(2,3-Dichloro-4-(thiophene-2-carbonyl)phenoxy)acetic acid, and the molecular formula is C13H8Cl2O4S, COA of Formula: C13H8Cl2O4S.
Referemce:
Benzothiophene – Wikipedia,
Benzothiophene | C8H6S – PubChem