Autonomic innervation to feline tracheal submucosal glands for mucus glycoprotein secretion

We examined the effect of electrical field stimulation (FS) on radiolabeled glycoconjugate released from feline tracheal isolated glands. Trichloroacetic acid precipitable [3H]-glycoconjugates released into the culture medium were counted, divided by the dry weight of sample, and data were expressed as percent of the release from the same animal that was unstimulated but otherwise received identical treatment. FS produced an increase in the glycoconjugate release that was dependent on the duration of stimulation, reaching a maximum response of 215% of nonstimulated sample for 30 min stimulation (10 Hz, 10 V). FS-evoked secretion was abolished by 10(-7) M tetrodotoxin but not altered by 10(-5) M hexamethonium. Atropine (10(-6) M) alone abolished the response to FS for 3 min or less. By contrast, a mixture of 10(-6) M atropine, 10(-5) M propranolol, and 10(-5) M phentolamine blocked only part of the response to FS for 15 min or more. The mixture of three antagonists reduced the response to FS for 30 min to 159% of control, which was significantly higher than control. Furthermore, 10(-6) M atropine, 10(-5) M propranolol, or 10(-5) M phentolamine significantly reduced the response to FS for 30 min to 162, 193, and 195%, respectively, from 215% of sample in the absence of blockers. Serotonin (10(-5) M) augmented FS-evoked response, which was abolished by 10(-6) M atropine or by 10(-5) M methysergide.(ABSTRACT TRUNCATED AT 250 WORDS)