Effects of the Peptide Leukotriene Receptor Antagonist ICI 198,615 on the In Vivo and In Vitro Changes in Guinea Pig Bladder Function Which Occur After Sensitization with Ovalbumin

1995 ◽  
Vol 154 (3) ◽  
pp. 1217-1221 ◽  
Author(s):  
Jeong Gu Lee ◽  
Robert M. Levin ◽  
Lev Krasnopolsky ◽  
Alan J. Wein ◽  
Penelope A. Longhurst
1989 ◽  
Vol 67 (9) ◽  
pp. 989-993 ◽  
Author(s):  
A. W. Ford-Hutchinson ◽  
Y. Girard ◽  
A. Lord ◽  
T. R. Jones ◽  
M. Cirino ◽  
...  

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.


1993 ◽  
Vol 235 (2-3) ◽  
pp. 211-219 ◽  
Author(s):  
Naoki Nakagawa ◽  
Takaaki Obata ◽  
Tadamasa Kobayashi ◽  
Yutaka Okada ◽  
Fumio Nambu ◽  
...  

1980 ◽  
Vol 48 (4) ◽  
pp. 613-618 ◽  
Author(s):  
J. M. Drazen ◽  
C. S. Venugopalan ◽  
M. W. Schneider

Effects of H2-receptor antagonism on the response to histamine was studied in the guinea pig in vivo and in vitro. The H2-receptor antagonist, metiamide (100 micro M), resulted in an enhanced histamine response in eight of eight parenchymal strips and in four of eight tracheal spirals. On the average the parenchymal strips were 20-fold more sensitive to histamine (P less than 0.001), whereas the tracheal spirals demonstrated an insignificant, 20%, increase in sensitivity after metiamide treatment. These results are consistent with the hypothesis that there are inhibitory H2-receptors in guinea pig airways and they predominate in the periphery. When we determined the effects of H2-antagonism on the histamine response in vivo we found that the histamine response was enhanced only in animals that had been treated with the beta-receptor antagonist propranolol. In these animals there was a mean 2.2-fold increase in histamine sensitivity. These results suggest that although there are inhibitory H2-receptors in the guinea pig lung, their role in modulating the in vivo response is much less than beta-adrenergic mechanisms.


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