title: Exposure to high environmental temperature in the sauna does not change plasma indocyanine green (ICG) clearance in healthy subjects.
abstract: Indocyanine green (ICG) was given intravenously (0.5 mg kg-1) to seven healthy male volunteers in random order during a control session and a session in the sauna bath. The sauna bathing session consisted of three 10 min. stays in the sauna (temperature 85-95 degrees, relative humidity 25-30%), separated by two 5-min. periods of resting at 22 degrees. Blood samples were taken for 60 min. in order to calculate ICG plasma clearance (CI), volume of distribution (Vss) and elimination half-life (t1/2 beta). The mean +/- S.E.M. values of ICG plasma clearance, Vss and t1/2 beta for the control session and the sauna bathing session were 0.47 +/- 0.08 1 min.-1 versus 0.39 +/- 0.04 1 min.-1, 2.4 +/- 0.4 1 versus 2.3 +/- 0.2 1 and 3.9 +/- 0.3 min. versus 4.4 +/- 0.3 min., respectively. No statistically significant differences in the CI, t1/2 beta or Vss of ICG were detected between the control and sauna bathing sessions. The results suggest that short-term exposure to high ambient temperatures during sauna bathing does not affect hepatic blood flow. Consequently, short-term hyperthermia and associated changes in hepatic blood flow are assumed to have little, if any, effect on the hepatic clearance of drugs.
authors.affiliation: Department of Pharmacology and Toxicology, University of Helsinki, Finland.
authors.forename: J
authors.initials: J
authors.lastname: Vanakoski
authors.forename: J J
authors.initials: JJ
authors.lastname: Idänpään-Heikkilä
authors.forename: T
authors.initials: T
authors.lastname: Seppälä
mesh_terms: D000328:Adult; D001831:Body Temperature; D001835:Body Weight; D006358:Hot Temperature; D006801:Humans; D007208:Indocyanine Green / Q000493:pharmacokinetics*; D007275:Injections, Intravenous; D008102:Liver Circulation; D008297:Male; D029002:Steam Bath / Q000009:adverse effects
chemical_list: D007208:Indocyanine Green