IL-6 increases airway resistance in the rat

The effect of angiotensin-converting enzyme inhibition by captopril on respiratory mechanics in healthy rats

“…The values of respiratory mechanics parameters here measured and calculated are similar to those previously obtained in analogous experiments performed in different laboratories 16,22,24,30,31 . Our finding of reduced R min,rs as an effect of ACE inhibition ( Figure 4) confirms that angiotensin exerts a bronchoconstrictor effect even in basal conditions [3][4][5] , suggesting that it may play a role in the modulation of airway calibre in healthy mammals.…”

“…Static pressure-volume relationships were assumed to be linear up to an inflation volume of 3 mL. This measurement is in agreement with published data showing essentially linear pressure-volume relationships for the rat respiratory system within this volume range 16,24,26,31 . The validity of this assumption has also been confirmed experimentally by the essentially linear pressure-volume relationships observed during static inflations performed for H y,rs measurements up to a total inflation volume of 5 mL (see below).…”

“…It has been shown that it is increased as an effect of increased lung blood volume and flow 31 , in inflamed lung tissue 24,33,34 , and decreased as an effect of body warming 16 , but it is not influenced by oestrous cycle in the rat 35 . Here, a possible effect of basal angiotensin plasma concentration on stress relaxation is hypothesised.…”

“…24 and related references). This excludes the possibility that any observed alterations were due to a timerelated effect.…”

“…The work of breathing (WOB rs ) values were calculated as previously described 16,24,25 , and outlined in Figure 2. Static pressure-volume relationships were assumed to be linear up to an inflation volume of 3 mL.…”