The maintenance of functional activity in human isolated bronchus after cryopreservation

Cryopreservation has been successfully used in the in vitro study of pharmacological responses of animal tissues and, to a limited extent, of human tissue. In this study, we examined the effect of cryopreservation on reactivity of human bronchus which was stored for a period of up to 3 weeks. Thirty-two bronchial rings were obtained from each of four transplantation donors (four male, aged 32 +/- 15 years SD). Eight rings from each patient were studied on day 0 (the day of retrieval) and an additional eight on days 7, 14 and 21, after cryopreservation in 1.8 M dimethyl sulfoxide in 1 ml foetal bovine serum at -190 degrees C. On day 0, all tissues from all patients contracted in response to either histamine or carbachol or relaxed in response to isoprenaline or levcromakalim. There was no significant difference in the mean Tmax or pD2 values for any agonist on days 7, 14 and 21 when responses were compared with those obtained on day 0. The major change induced by cryopreservation was observed in the response to antigen. Tissues from three of the four donors contracted to the administration of Dermatophagoides pteronyssinus on day 0. However, when tissues from these same donors were studied on days 7, 14 and 21, they did not contract to this antigen. The results of this study indicate that human bronchial tissue may be successfully cryopreserved to maintain contractile and relaxant responses to various agonists. However, the response to antigen in tissues, which on day 0 of study were determined to be sensitized, was not present after cryopreservation.