The effect of rapid cooling and culture on in vitro insulin release in cryopreserved rat islets of Langerhans.

It has been reported that isolated pancreatic islets are functionally viable following cryopreservation using fast cooling and that such conditions should be more efficient for the selective destruction of immunocompetent passenger lymphoid cells than techniques employing slow cooling. This study examines the effect of extended pre-freeze and post-thaw culture (72 hr) on the in vitro function of rapidly cooled (70 degrees C/min) rat islets of Langerhans. The viability of the islets was assessed by their ability to secrete insulin in response to stimulation by glucose and theophylline both statically during batch incubations and dynamically in a perifusion system. Extended tissue culture was found to be essential for the retention of insulin secretory function of rapidly cooled islets which showed slightly suppressed but comparable secretion indices compared with non-frozen cultured islets.