for the monitoring of pulmonary mechanics a buxco pulmonary mechanics computer is used to calculate pulmonary resistance dynamic compliance and tidal volume from transpulmonary pressure and flow data respiratory rate heart rate and mean arterial blood pressure are also monitored the femoral vein is cannulated for the delivery of drugs pilocarpine nitrate 0 2 mg kg hr is than infused to induce a bronchospasm and salivary flow bunolol 0 5 mg kg i v is given 30 minutes prior to the pilocarpine to reduce the protein content hence the viscosity of the saliva salivary output is collected from a catheterized wharton 39 s duct at five minute intervals after salivation has stabilized 3 control collections are taken at 5 minute intervals followed by a series of cumulative i v doses of test compound 1 3 10 30 100 300 1000 3000 and 10 000 u03bcg kg that are injected every 5 minutes for 45 minutes the percent inhibition of both the bronchospasm and salivation are calculated for each dose with a return to pre pilocarpine resistance levels or cessation of salivation equal to a 100 inhibition utilizing this procedure the following results were obtained for representative compounds of the invention ______________________________________ str10 id sub 50 pulmo u03bcg kg nary broncho id sub 50 u03bcg kg selec r sub 1r sub 2 r sub 3 x y spasm salivation tivity ______________________________________h me h me me 114 421 3 7h me h me et 150 336 2 2h me h et et 111 510 4 6h h h me me 192 4147 22h h h.