Effect of Alpha-adrenergic Stimulation on Mucus Secretion and on Ion Transport in Cat Trachea in Vitro

In cat trachea mounted in Ussing chambers, we studied the effects of an alpha-adrenergic agonist on mucus secretion measured with 35S bound to sulfated glycoproteins, and on fluxes of Na+ and Cl- ions measured with 22Na and 36Cl, under open-circuit conditions. Phenylephrine (10(-5) M), increased bound 35S-secretion by 147 +/- 24% (mean +/- SE, n = 13), increased JCl-S yields L from 2.54 +/- 0.23 to 7.40 +/- 1.19 microEq/cm2/h (n = 6), and increased JNaS yields L from 1.75 +/- 0.36 to 7.25 +/- 1.10 microEq/cm2/h (n = 6), it decreased 4Cl--L yields S from 2.69 +/- 0.41 to 2.46 +/- 0.41 microEq/cm2/h, but did not change JNa+L yields S. The stimulatory effects of (10(-5) M) phenylephrine were prevented by (10(-5) M) phentolamine, but were unaffected by (10(-5) M) propranolol. In contrast, (10(-5) M) terbutaline, a beta 2-adrenergic agonist, only increased bound 35S secretion by 43 +/- 7% (n = 22) and only increased JCl-S yields L from 3.76 +/- 0.46 to 4.55 +/- 0.41 microEq/cm2/h (n = 6); it did not change the other fluxes. These findings indicate that alpha-adrenergic stimulation causes secretion of sulfated glycoproteins and ion-mediated movement of water into the cat trachea.