Function of cryopreserved pig aortas.
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.
Rendal
E
E
Cryobiology Unit, Complejo Hospitalario Juan Canalejo, Carretera del Pasaje s/n, Hospital Teresa Herrera, 15006 La Coruña, Spain. Esther_Rendal@canalejo.org
Rodríguez
M
M
Martínez
M V
MV
Fernández
R O
RO
Sánchez
J
J
Segura
R
R
Bermúdez
T
T
Matheu
G
G
Filgueira
P
P
Pértega
S
S
Andión
C
C
D000818:Animals; D001011:Aorta / Q000473:pathology / Q000503:physiopathology*; D015925:Cryopreservation; D004730:Endothelium, Vascular / Q000473:pathology / Q000503:physiopathology; D013552:Swine; D014661:Vasoconstriction; D014664:Vasodilation