title: Human G protein beta3 subunit variant does not alter hypercarbic or hypoxic ventilatory response.
abstract: Hypercarbic respiratory drive is mainly determined by PCO(2) and pH with activity of the intracellular Na+/H+ exchanger (NHE) playing an important role in maintaining intracellular pH and respiratory drive. Because NHE activity varies with genetically different G-protein beta3 subunits (GNB3) (C/T polymorphism at nucleotide position 825) different genotypes might alter respiratory regulation. To test the hypothesis that short-term ventilatory responses vary with different GNB3 healthy volunteers with different genotypes (CC, TC, TT) were exposed to either hyperoxic hypercarbia (n=33) or to isocapnic hypoxia (n=31), respectively. There was no difference between CC, TC, and TT genotypes in hypercarbic and hypoxic respiratory drive when assessed as the ratio of minute ventilation over endexpiratory PCO(2) changes (DeltaV.E/DeltaPETCO(2)), maximal tolerable PETCO(2), and ratio of changes in ventilation over arterial haemoglobin desaturation (DeltaV.E/DeltaSO(2)), respectively. Thus, short-term hypercarbic and hypoxic ventilatory drive do not differ between individuals with genotypes encoding different GNB3. Whilst respiratory control may still be influenced by G-protein aberration, other mechanisms seem to have a more important role in controlling ventilation.
authors.affiliation: Abteilung für Anästhesiologie und Intensivmedizin, Universitätsklinikum Essen, Hufeland Strasse 55, D-45122 Essen, Germany.
authors.forename: H J
authors.initials: HJ
authors.lastname: Exner
authors.forename: H
authors.initials: H
authors.lastname: Groeben
authors.forename: D
authors.initials: D
authors.lastname: Rosskopf
authors.forename: W
authors.initials: W
authors.lastname: Siffert
authors.forename: J
authors.initials: J
authors.lastname: Peters
mesh_terms: D005838:Genotype; D020962:Heterotrimeric GTP-Binding Proteins / Q000235:genetics / Q000502:physiology*; D006801:Humans; D006935:Hypercapnia / Q000235:genetics / Q000503:physiopathology*; D000860:Hypoxia / Q000235:genetics / Q000503:physiopathology*; D008297:Male; D010641:Phenotype; D011110:Polymorphism, Genetic / Q000502:physiology; D012119:Respiration; D015656:Respiratory Mechanics
chemical_list: D020962:Heterotrimeric GTP-Binding Proteins