title: Endocrine regulation of subcutaneous fat metabolism during cold exposure in humans.
abstract: Increased oxidation of carbohydrates and free fatty acids is a well-known phenomenon during cold stress. Nevertheless, sources of the fuels used have not been fully clarified as yet. Thus, the aim of our study was to evaluate the effect of acute cold exposure on lipid and carbohydrate metabolism in human subcutaneous adipose tissue and to identify the possible regulatory mechanisms involved. Ten volunteers were exposed for 30 min to an ambient temperature of 4 degrees C. Interstitial metabolism was assessed with the aid of the microdialysis technique. Lipolysis intensity was evaluated from changes of glycerol concentration in plasma and in dialysate. Cold exposure induced a significant increase of glycerol concentration both in plasma (by 199 +/- 16%, p < 0.01) and in dialysate (by 308 +/- 58%, p < 0.001). No changes in glucose concentration were found whether in plasma or in the dialysate. Ethanol concentration in dialysate increased (148 +/- 15%, p < 0.01), indicating a slower blood flow in the subcutaneous region. Plasma concentrations of various gluco- and/or lipid-regulatory hormones remained unaffected by the cold exposure, except for norepinephrine, which rose about threefold (309 +/- 41%, p < 0.001). The data indicate an important role for subcutaneous adipose tissue in mobilization of free fatty acids during cold exposure. This process seems to be regulated by the sympathetic nervous system, whereas hormones involved in the regulation of lipid metabolism, such as epinephrine, insulin, cortisol, and growth hormone, may play a less significant role-at least under the conditions studied.
authors.affiliation: Institute of Experimental Endocrinology, Slovak Academy of Sciences, Bratislava, Slovak Republic. ueenjkos@savba.sk
authors.forename: Juraj
authors.initials: J
authors.lastname: Koska
authors.forename: Lucia
authors.initials: L
authors.lastname: Ksinantova
authors.forename: Elena
authors.initials: E
authors.lastname: Seböková
authors.forename: Richard
authors.initials: R
authors.lastname: Kvetnansky
authors.forename: Iwar
authors.initials: I
authors.lastname: Klimes
authors.forename: George
authors.initials: G
authors.lastname: Chrousos
authors.forename: Karel
authors.initials: K
authors.lastname: Pacak
mesh_terms: D000273:Adipose Tissue / Q000378:metabolism*; D000328:Adult; D001786:Blood Glucose / Q000032:analysis; D004702:Endocrine Glands / Q000502:physiology*; D005260:Female; D005990:Glycerol / Q000097:blood; D006728:Hormones / Q000097:blood; D006801:Humans; D008297:Male
chemical_list: D001786:Blood Glucose; D006728:Hormones; D005990:Glycerol