title: Luminal purinergic regulatory mechanisms of tracheal ciliary beat frequency.
abstract: To investigate the modulation of tracheal ciliary beat frequency (CBFt) by purine nucleotides and nucleosides acting on luminal receptors, aerosolized ATP, GTP, AMP-PNP, GMP-PNP, adenosine, and guanosine were each administered separately to the tracheal lumen in eucapnically ventilated, barbiturate-anesthetized beagles. Four studies were conducted in each of seven dogs from a cohort of eight dogs. The CBFt responses were measured on the right lateral surface of the mid-trachea using heterodyne mode correlation analysis laser light scattering. Aerosolized 10(-6) M and 10(-5) M ATP stimulated CBFt from the baseline of 5.9 +/- 1.4 Hz to maxima of 12.1 +/- 1.4 Hz and 13.3 +/- 1.6 Hz, respectively, while the same corresponding ATP-analogue (AMP-PNP) concentrations stimulated baseline CBFt to maxima of 12.7 +/- 4.1 Hz and 18.1 +/- 2.1 Hz, respectively. Similarly, 10(-6) M and 10(-5) M GTP stimulated baseline CBFt to maxima of 14.8 +/- 1.1 Hz and 12.8 +/- 4.6 Hz, respectively. The corresponding GTP-analogue (GMP-PNP) concentrations stimulated CBFt to maxima of 14.5 +/- 2.1 Hz and 18.8 +/- 4.4 Hz, respectively. Prior delivery of 10(-5) M adenosine reduced all these nucleotide-induced stimulatory responses. Prior delivery of 10(-5) guanosine partially reduced the GTP- and the GMP-PNP-induced stimulatory responses. These data demonstrate that nucleotides and nucleosides modulate CBFt through specific P2 and P1 purinergic receptors on the luminal surface, thus providing a direct mechanism within the airways to enhance the transport of mucus.
authors.affiliation: Department of Medicine, University of Illinois, Chicago 60612.
authors.forename: L B
authors.initials: LB
authors.lastname: Wong
authors.forename: D B
authors.initials: DB
authors.lastname: Yeates
mesh_terms: D000241:Adenosine / Q000494:pharmacology; D000255:Adenosine Triphosphate / Q000494:pharmacology; D000266:Adenylyl Imidodiphosphate / Q000494:pharmacology; D000336:Aerosols; D000818:Animals; D002923:Cilia / Q000187:drug effects / Q000502:physiology*; D004285:Dogs; D006160:Guanosine Triphosphate / Q000494:pharmacology; D006165:Guanylyl Imidodiphosphate / Q000494:pharmacology; D013997:Time Factors; D014132:Trachea / Q000502:physiology*
chemical_list: D000336:Aerosols; D000266:Adenylyl Imidodiphosphate; D006165:Guanylyl Imidodiphosphate; D006160:Guanosine Triphosphate; D000255:Adenosine Triphosphate; D000241:Adenosine