Relaxant profile of synthetic atrial natriuretic factor on guinea-pig pulmonary tissues.

Synthetic atrial natriuretic factor (ANF) (3.22 X 10(-7)-9.67 X 10(-9) M) produced relaxation of the intrinsic and extrinsic tone of the guinea-pig trachea. ANF was more potent on the trachea as compared to the parenchyma of the guinea-pig. On the trachea ANF was a more potent relaxant of intrinsic tonus or contractions induced by methacholine as compared to contractions induced by leukotriene D4. When administered by aerosol to anesthetized spontaneously breathing guinea-pigs, ANF produced neither bronchodilation nor inhibition of bronchoconstriction induced by an aerosol of leukotriene D4.