Comparative study of the pulmonary effects of intravenous XXXX and other bronchoconstrictors in anaesthetized @entity840 .

@entity1439 @entity3858 @entity6839 @entity4443 @entity840 @entity1426 @entity8765 @entity619 @entity3543 @entity3897 @entity112 @entity3352 @entity934
Pulmonary responses to intravenous @entity4443 C4, D4 and E4 administered as a bolus injection and by continuous infusion were studied in anesthetized @entity840 . LTD4, LTC4 and LTE4 (respective ED50 of 0.21 +/- .1, 0.64 +/- .2 and 2.0 +/- .1 microgram kg-1) produced dose-dependent increases in insufflation pressure when given as a bolus injection to anesthetized @entity840 (Konzett-R  ssler). Bronchoconstriction was antagonized by @entity1439 (50-200 micrograms kg-1), and @entity3352 (50-200 micrograms kg-1) but was not significantly altered by @entity8765 (1.0 mg kg-1), @entity3858 (0.1 mg kg-1), intal (10 mg kg-1) @entity3543 (5 mg kg-1) or @entity619 (10 mg kg-1). The beta adrenoceptor blocker, @entity6839 (5 micrograms kg-1) produced a significantly greater potentiation of the responses to the @entity4443 than to @entity1426 , @entity112 and @entity934 . Responses to bolus injection of LTE4 but not LTD4 or LTC4 were partially antagonized by @entity3897 (100 micrograms kg-1) and bilateral vagotomy. In experiments of a different design, continuous infusion of LTD4 and LTE4 (2.8-3.2 micrograms kg-1 min-1) into @entity3352 -treated animals produced slowly developing increases in pulmonary resistance and decreases in compliance. The increase in resistance produced by LTE4 and LTD4 was partly reversed by intravenous @entity1439 (1.0 mg kg-1) and @entity3897 (100 micrograms kg-1) but was almost completely reversed by @entity1439 (3 - 10 mg kg-1). These findings indicate that @entity4443 can produce bronchoconstriction in @entity840 through cyclooxygenase-dependent and cyclooxygenase independent mechanisms both of which are blocked by @entity1439 . Cholinergic mechanisms are involved in the mediation of part of the response to bolus injection of LTE4 as well as a small part of the initial response to continuous infusion of LTD4 and LTE4. Intrinsic beta adrenoceptor activation serves to down modulate responses to the @entity4443 to a greater extent than responses to @entity1426 , @entity112 and @entity934 .
