L-649,923, Sodium (βS*, γR*)-4-(3-(4-acetyl-3-hydroxy-2-propylphenoxy)-propylthio)-γ-hydroxy-β-methylbenzenebutanoate, a selective, orally active leukotriene receptor antagonist

1986 ◽  
Vol 64 (8) ◽  
pp. 1068-1075 ◽  
Author(s):  
T. R. Jones ◽  
R. Young ◽  
E. Champion ◽  
L. Charette ◽  
D. Denis ◽  
...  
Keyword(s):  
Guinea Pig ◽  
Competitive Inhibition ◽  
Competitive Inhibitor ◽  
Plot Analysis ◽  
Prostaglandin F ◽  
Leukotriene Receptor ◽  
Orally Active ◽  
Intraduodenal Administration

L-649,923, Sodium (βs*, γR*)-4-(3-(4-acetyi-3-hydroxy-2-propylphenoxy)propylthio)-γ-hydroxy-β-methylbenzenebutanoate is a selective and competitive inhibitor of [3H]leukotriene D4 (Ki value of 400 nM) and to a lesser extent [3H]leukotriene C4 (Ki value of 8.6 μM) binding in guinea-pig lung homogenates. Functionally, it selectively antagonized contractions of guinea pig trachea induced by leukotriene C4, D4, E4, and F4 but not those induced by acetylcholine, histamine, serotonin, prostaglandin F2α, or U-44069 (stable endoperoxide analogue). Schild plot analysis indicated a competitive inhibition of contractions of guinea-pig ileum induced by leukotriene D4 (pA2 8.1) and contractions of guinea-pig trachea induced by leukotrienes E4 and F4 (pA2 7.1 and 6.9, respectively). In contrast, contractions of guinea-pig trachea induced by leukotrienes C4 (pA2 7.2; slope 0.6) and D4 (pA2 7.2; slope 0.7) were inhibited in a noncompetitive fashion. In vivo, intravenously administered L-649,923 selectively blocked bronchoconstriction induced in anesthetized guinea pigs by leukotriene C4 and D4 (ED50 values i.v. 0.38 and 0.26 mg/kg, respectively) but not that induced by histamine, arachidonic acid, serotonin, U-44069, or acetylcholine. Following intraduodenal administration, L-649,923, blocked leukotriene D4 induced bronchoconstriction (5 and 10 mg/kg). The present findings indicate that selective antagonists, such as L-649,923, may be useful for defining the role of leukotrienes in diseases such as bronchial asthma.

L-648,051, sodium 4-[3-(4-acetyl-3-hydroxy-2-propylphenoxy)-propylsulfonyl]-γ-oxo-benzenebutanoate: a leukotriene D4 receptor antagonist

1986 ◽  
Vol 64 (12) ◽  
pp. 1535-1542 ◽  
Author(s):  
T. R. Jones ◽  
Y. Guindon ◽  
R. Young ◽  
E. Champion ◽  
L. Charette ◽  
...  
Keyword(s):  
Guinea Pig ◽  
Competitive Inhibitor ◽  
Topical Agent ◽  
Guinea Pig Ileum ◽  
Leukotriene D4 ◽  
Plot Analysis ◽  
Prostaglandin F ◽  
D4 Receptor ◽  
Intraduodenal Administration

L-648,051, sodium 4-[3-(4-acetyl-3-hydroxy-2-propylphenoxy)propylsulfonyl]-γ-oxo-benzenebutanoate is a selective and competitive inhibitor of [3H]leukotriene D4 (KB value of 4.0 μM) and to a lesser extent [3H]leukotriene C4 (Ki value of 36.7 μM) binding in guinea pig lung homogenates. Functionally, it selectively antagonized contractions of guinea pig trachea induced by leukotrienes C4, D4, E4, and F4 in concentrations that did not antagonize contractions induced by acetylcholine, histamine, serotonin, prostaglandin F2α, or U-44069 (endoperoxide analogue). Schild plot analysis indicated that L-648,051 competitively antagonized contractions of guinea pig ileum induced by leukotriene D4 (pA2 7.7) and contractions of trachea induced by leukotrienes D4, E4, and F4 (pA2 7.3, 7.4, and 7.5, respectively). Contractions of guinea pig trachea induced by leukotriene C4 were inhibited in a noncompetitive fashion (Schild plot slope, 0.45). Developed contractions of trachea induced by the leukotrienes were rapidly reversed by L-648,051 > FPL-55712 > L-649,923. Intravenous L-648,051 selectively blocked bronchoconstriction induced in anaesthetized guinea pigs by intravenous leukotrienes C4, D4, and E4 but not that induced by arachidonic acid, serotonin, U-44069, or acetylcholine. The compound displayed poor activity following intraduodenal administration. The profile of activity for L-648,051 indicates that it may be a useful topical agent for studying the role of leukotrienes in diseases such as bronchial asthma.

Maintenance of tone, role of arachidonate metabolites, and effects of sensitization in guinea pig trachea

1986 ◽  
Vol 64 (8) ◽  
pp. 1096-1103 ◽  
Author(s):  
S. Mansour ◽  
E. E. Daniel
Keyword(s):  
Guinea Pig ◽  
Initial Level ◽  
Underlying Mechanism ◽  
Active Tension ◽  
Tone Production ◽  
High Tension ◽  
Prostaglandin F ◽  
Arachidonate Metabolites ◽  
Low Tension

A study was made of the mechanisms underlying production of resting active tension in guinea pig tracheal smooth muscle and the changes with active sensitization to ovalbumin. The same types of tissues were also analyzed as to their responses to arachidonate. Responses for each tissue were expressed in relation to a scale between zero active tension and maximum active tension in response to carbachol. A variety of selective and nonselective inhibitors of cyclooxygenase or 5-lipoxygenase were shown to affect active tension in a manner consistent with the conclusion that a cyclooxygenase product, probably prostaglandin F(PGF2α) and not thromboxanes was chiefly responsible. The inhibition of active tension produced by cyclooxygenase inhibition was shown to be related to the initial active tension, such that tissues with greater resting active tension had greater reductions in tone. No differences of major importance were found as to the mechanisms underlying tone production in control and sensitized tissues. The tension changes in response to exogenous arachidonate were also found to be dependent on the initial level of active tension; when this was low, tension increased, when it was high, tension decreased or did not change. Effects of inhibitors on these responses were again consistent with the conclusion that primarily excitant prostaglandins, not thromboxanes, were produced. Some suggestive evidence for production of excitatory and inhibitory nonprostaglandin metabolites was obtained. No difference of major importance between control and sensitized tissues was observed in the magnitude or underlying mechanism of production of active tension.

Pharmacology of MK-0591 (3-[1-(4-chlorobenzyl)-3-(t-butylthio)-5-(quinolin-2-yl-methoxy)-indol-2-yl]-2,2-dimethyl propanoic acid), a potent, orally active leukotriene biosynthesis inhibitor

1992 ◽  
Vol 70 (6) ◽  
pp. 799-807 ◽  
Author(s):  
C. Brideau ◽  
C. Chan ◽  
S. Charleson ◽  
D. Denis ◽  
J. F. Evans ◽  
...  
Keyword(s):  
Polymorphonuclear Leukocytes ◽  
Potent Inhibitor ◽  
Ex Vivo ◽  
Late Phase ◽  
Squirrel Monkeys ◽  
Propanoic Acid ◽  
Orally Active

MK-0591 (3-[1-(4-chlorobenzyl)-3-(t-butylthio)-5-(quinolin-2-yl-methoxy)-indol-2-yl]-2,2-dimethyl propanoic acid, previously L-686,708) is a potent inhibitor of leukotriene (LT) biosynthesis in intact human and elicited rat polymorphonuclear leukocytes (PMNLs) (IC50 values 3.1 and 6.1 nM, respectively) and in human, squirrel monkey, and rat whole blood (IC50 values 510, 69, and 9 nM, respectively). MK-0591 had no effect on rat 5-lipoxygenase. MK-0591 has a high affinity for 5-lipoxygenase activating protein (FLAP) as evidenced by an IC50 value of 1.6 nM in a FLAP binding assay and inhibition of the photoaffinity labelling of FLAP by two different photoaffinity ligands. Inhibition of activation of 5-lipoxygenase was shown through inhibition of the translocation of the enzyme from the cytosol to the membrane in human PMNLs. MK-0591 was a potent inhibitor of LT biosynthesis in vivo, first, following ex vivo challenge of blood obtained from treated rats and squirrel monkeys, second, in a rat pleurisy model, and, third, as monitored by inhibition of the urinary excretion of LTE4 in antigen-challenged allergic sheep. Inhibition of antigen-induced bronchoconstriction by MK-0591 was observed in inbred rats pretreated with methysergide, Ascaris-challenged squirrel monkeys, and Ascaris-challenged sheep (early and late phase response). These results indicate that MK-0591 is a potent inhibitor of LT biosynthesis both in vitro and in vivo indicating that the compound will be suitable for assessing the role of leukotrienes in pathological situations.Key words: leukotriene, 5-lipoxygenase, leukotriene inhibitor, bronchoconstriction, inflammation, 5-lipoxygenase activating protein.

Pharmacology of L-660,711 (MK-571): a novel potent and selective leukotriene D4 receptor antagonist

1989 ◽  
Vol 67 (1) ◽  
pp. 17-28 ◽  
Author(s):  
T. R. Jones ◽  
R. Zamboni ◽  
M. Belley ◽  
E. Champion ◽  
L. Charette ◽  
...  
Keyword(s):  
Guinea Pig ◽  
Receptor Antagonist ◽  
Guinea Pigs ◽  
Competitive Inhibitor ◽  
Dose Ratio ◽  
Leukotriene D4 ◽  
Small Component ◽  
Human Trachea ◽  
D4 Receptor ◽  
Orally Active

L-660,711 (3-(3-(2-(7-chloro-2-quinolinyl)ethenyl)phenyl) ((3-dimethyl amino-3-oxo propyl)thio)methyl)thio)propanoic acid is a potent and selective competitive inhibitor of [3H]leukotriene D4 binding in guinea pig (Ki value, 0.22 nM) and human (Ki value, 2.1 nM) lung membranes but is essentially inactive versus [3H]leukotriene C4 binding (IC50 value in guinea pig lung, 23 μM). Functionally it competitively antagonized contractions of guinea pig trachea and ileum induced by leukotriene (LT) D4 (respective pA2 values, 9.4 and 10.5) and LTE4 (respective pA2 values, 9.1 and 10.4) and contractions of human trachea induced by LTD4 (pA2 value, 8.5). L-660,711 (5.8 × 10−8 M) antagonized contractions of guinea pig trachea induced by LTC4 in the absence (dose ratio = 28) but not in the presence of 45 mM L-serine borate (dose ratio <2). L-660,711 (1.9 × 10−5 M) did not block contractions of guinea pig trachea induced by histamine, acetylcholine, 5-hydroxytryptamine, PGF2α, U-44069, or PGD2. In the presence of atropine, mepyramine, and indomethacin, L-660,711 (1.9 × 10−5 M) inhibited a small component of the response to antigen on guinea pig trachea but completely blocked anti-IgE-induced contractions of human trachea. L-660,711 (i.v.) antagonized bronchoconstriction induced in anesthetized guinea pigs by i.v. LTC4, LTD4, and LTE4 but did not block bronchoconstriction to arachidonic acid, U-44069, 5-hydroxytryptamine, histamine, or acetylcholine. Intraduodenal L-660,711 antagonized LTD4 (0.2–12.8 μg/kg) -induced bronchoconstriction in guinea pigs, and p. o. L-660,711 blocked LTD4- and Ascaris-induced bronchoconstriction in conscious squirrel monkeys and ovalbumin-induced bronchoconstriction in conscious sensitized rats treated with methysergide (3 μg/kg). The pharmacological profile of L-660,711 indicates that it is a potent, selective, orally active leukotriene receptor antagonist which is well suited to determine the role played by LTD4 and LTE4 in asthma and other pathophysiologic conditions.

scholarly journals The subcellular localization of di- and tri-peptide hydrolase activity in guinea-pig small intestine

1970 ◽  
Vol 120 (1) ◽  
pp. 195-203 ◽  
Author(s):  
T. J. Peters
Keyword(s):  
Guinea Pig ◽  
Brush Border ◽  
Soluble Fraction ◽  
Subcellular Fractionation ◽  
Border Region ◽  
Protein Digestion ◽  
Kinetic Assay ◽  
Brush Borders

1. Two different subcellular fractionation techniques were applied to guinea-pig intestinal mucosa and the composition of the brush borders prepared by the two methods were compared. 2. By using a kinetic assay system the subcellular distribution of activity against ten dipeptides and five tripeptides was studied. 3. Only small amounts (5–10%) of activity against dipeptides were found in the brush-border region, the enzymes being concentrated in the cytosol. 4. Significant amounts (10–60%) of activity against tripeptides were found in the brush border with the remainder largely present in the soluble fraction. 5. The relevance of these studies to the localization in vivo and the possible role of peptidases in protein digestion is discussed.

The pharmacology of L-670,596, a potent and selective thromboxane/prostaglandin endoperoxide receptor antagonist

1989 ◽  
Vol 67 (9) ◽  
pp. 989-993 ◽  
Author(s):  
A. W. Ford-Hutchinson ◽  
Y. Girard ◽  
A. Lord ◽  
T. R. Jones ◽  
M. Cirino ◽  
...  
Keyword(s):  
Platelet Aggregation ◽  
Guinea Pig ◽  
Receptor Antagonist ◽  
Competitive Inhibition ◽  
Ex Vivo ◽  
Platelet Rich Plasma ◽  
Prostaglandin Endoperoxide ◽  
Induced Aggregation

L-670,596 ((−)6,8-difluoro-9-p-methylsulfonyl benzyl-1,2,3,4-tetrahydrocarbazol-1-yl-acetic acid) has been shown to be a potent receptor antagonist as evidenced by the inhibition of the binding of 125I-labeled PTA-OH to human platelets (IC50, 5.5 × 10−9 M), inhibition of U-44069 induced aggregation of human platelet rich plasma (IC50, 1.1 × 10−7 M), and competitive inhibition of contractions of the guinea pig tracheal chain induced by U-44069 (pA2,9.0). The compound was also active in vivo as shown by inhibition of arachidonic acid and U-44069 induced bronchoconstriction in the guinea pig (ED50 values, 0.04 and 0.03 mg/kg i.v., respectively), U-44069 induced renal vasoconstriction in the pig (ED50, 0.02 mg/kg i.v.), and inhibition of ex vivo aggregation of rhesus monkey platelets to U-44069 (active 1–5 mg/kg p.o.). The selectivity of the compound was indicated by the failure to inhibit, first, ADP-induced human or primate platelet aggregation and, second, bronchoconstriction in the guinea pig in vivo and contraction of the guinea pig tracheal chain in vitro to a variety of agonists. It is concluded that L-670,596 is a potent, selective, orally active thromboxane A2/prostaglandin endoperoxide receptor antagonist.Key words: thromboxane A2, thromboxane antagonist, prostaglandin endoperoxides, platelet aggregation.

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