title: B-type natriuretic peptide secretion following scuba diving.
abstract: OBJECTIVE
  To examine the neurohormonal effects of a scuba dive, focusing on the acute changes in the plasma concentrations of the different peptide fragments from the B-type natriuretic peptide (BNP) precursor.
  
  
  METHODS
  We studied 12 healthy scuba divers (mean age ± standard deviation: 44 ± 7 years; range: 34-55 years; BMI: 24.8 ± 2.8 kg/m(2)), who performed a 15-m depth dive in salt water, with a bottom time of 30 min. Blood samples for BNPs (pro-B-type natriuretic peptide [pro-BNP], BNP and aminoterminal pro-BNP) and catecholamines were measured in plasma before immersion, and after the dive. A continuous electrocardiographic recording was obtained during the entire protocol.
  
  
  RESULTS
  BNP, aminoterminal pro-BNP and pro-BNP plasma concentrations slightly, but significantly, increased after the scuba dive (18 ± 15 to 21 ± 11 ng/l, p = 0.020; 32 ± 19 to 38 ± 21 ng/l, p = 0.008; and 7.8 ± 1.6 to 10.3 ± 3.6 ng/l, p = 0.028, respectively) in parallel with norepinephrine concentration (743 ± 323 to 1163 ± 656 ng/l, p = 0.014), with no variations in total plasma proteins, hematocrit or osmolality. A persistent sinus tachycardia was observed during all phases of the dive.
  
  
  CONCLUSIONS
  A 15-m depth scuba dive induces an acute slight release of the different peptide fragments from the BNP precursor, likely through the stimulation of a constitutive secretory pathway promoted by adrenergic activation and cardiac chamber dilation.
authors.affiliation: Department of Cardiovascular Medicine, Fondazione G Monasterio, Pisa, Italy. passino@ifc.cnr.it
authors.forename: Claudio
authors.initials: C
authors.lastname: Passino
authors.forename: Enrico
authors.initials: E
authors.lastname: Franzino
authors.forename: Alberto
authors.initials: A
authors.lastname: Giannoni
authors.forename: Concetta
authors.initials: C
authors.lastname: Prontera
authors.forename: Jens Peter
authors.initials: JP
authors.lastname: Goetze
authors.forename: Michele
authors.initials: M
authors.lastname: Emdin
authors.forename: Aldo
authors.initials: A
authors.lastname: Clerico
mesh_terms: D000328:Adult; D004242:Diving / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain / Q000378:metabolism*; D018377:Neurotransmitter Agents / Q000378:metabolism; D009638:Norepinephrine / Q000378:metabolism
chemical_list: D018377:Neurotransmitter Agents; D020097:Natriuretic Peptide, Brain; D009638:Norepinephrine