title: Function of cryopreserved pig aortas.
abstract: OBJECTIVE
  This paper analyzes the influence of storage in the gas phase or liquid phase on grafts, together with the thawing method (15 degrees C/min or 100 degrees C/min) on the postthawing activity of pig cryopreserved arterial grafts (aortas).
  
  
  METHODS
  Obtainment of arterial grafts (aortas) was from pigs with an ischemic time not greater than 2 h. Each aorta was divided into five fragments and assigned randomly to one control group of fresh aorta and four groups of cryopreserved aortas: group 1: gas phase/slow thawing; group 2: gas phase/rapid thawing; group 3: liquid phase/slow thawing; and group 4: liquid phase/rapid thawing. After the incubation in antibiotic solution, the cryopreservation in RPMI medium +10% DMSO was carried out and the level of cooling used was a reduction of 1 degrees C/min. The contraction and relaxation responses of the fresh and frozen/thawed arteries were carried out in organ baths.
  
  
  RESULTS
  After thawing, the sensitivity to various agonists and maximal responses to the endothelium-dependent and independent relaxant agents were decreased. The maximal responses to the tested vasoconstrictors (KCl and noradrenaline) were, respectively, 13% and 24% of the responses obtained in unfrozen aortas. The endothelium-independent relaxant responses to sodium nitroprusside (SNP) were reduced and important reductions of the endothelium-dependent relaxant responses to acetylcholine were produced.
  
  
  CONCLUSIONS
  The cryopreservation of pig aortas under the conditions used in this study led to a decrease in the contractility of the pig aortas, as well as a decrease in the endothelium-independent relaxant responses. On the other hand, no apparent preservation of the endothelium-dependent relaxant responses was observed.
authors.affiliation: Cryobiology Unit, Complejo Hospitalario Juan Canalejo, Carretera del Pasaje s/n, Hospital Teresa Herrera, 15006 La Coruña, Spain. Esther_Rendal@canalejo.org
authors.forename: E
authors.initials: E
authors.lastname: Rendal
authors.forename: M
authors.initials: M
authors.lastname: Rodríguez
authors.forename: M V
authors.initials: MV
authors.lastname: Martínez
authors.forename: R O
authors.initials: RO
authors.lastname: Fernández
authors.forename: J
authors.initials: J
authors.lastname: Sánchez
authors.forename: R
authors.initials: R
authors.lastname: Segura
authors.forename: T
authors.initials: T
authors.lastname: Bermúdez
authors.forename: G
authors.initials: G
authors.lastname: Matheu
authors.forename: P
authors.initials: P
authors.lastname: Filgueira
authors.forename: S
authors.initials: S
authors.lastname: Pértega
authors.forename: C
authors.initials: C
authors.lastname: Andión
mesh_terms: D000818:Animals; D001011:Aorta / Q000473:pathology / Q000503:physiopathology*; D015925:Cryopreservation; D004730:Endothelium, Vascular / Q000473:pathology / Q000503:physiopathology; D013552:Swine; D014661:Vasoconstriction; D014664:Vasodilation