Maintenance of insulin release from pancreatic islets stored in the cold for up to 5 weeks.

Abstract

A B S T R A C T Insulin content and release were measured from hand-dissected pancreatic islets from noninbred ob/ob mice after 1-5 wk storage in tissue culture medium 199 at various temperatures and glucose concentrations.After storage of islets for 1 wk at 37°, 22°, or 80C in 18 mM glucose medium and preincubation with 1 mM glucose, glucose-stimulated insulin release during the subsequent incubation was only 20-35% of that of fresh islets. The addition of a 4-h period at 370C with 18 mM glucose between the cold storage and perincubation restored glucose-stimulated insulin release from 80C-stored islets to fresh-islet levels. Release throughout the 1-18 mM glucose range was strikingly parallel to that of fresh islets. Exposure of fresh islets to the same 4-h period increased basal release but did not affect maximal release.When islets were stored at 80C with 18 mM glucose for more than 1 wk, a short period at 370C every week was necessary for maintenance of release. After 5 wk of this procedure, glucose-stimulated insulin release was one-third that of fresh islets, or similar to that of islets stored for only 1 wk at 370C. Storage at 80C for 1 wk with 3 mM glucose, or continuously for 3 or 5 wk with 18 mM glucose, maintained islet insulin content, whereas release was lost.Thus, glucose-stimulated insulin release is best maintained by storage of pancreatic islets in tissue culture medium with a high concentration of glucose at 80C with short weekly periods at 370C.

Insulin and Glucagon Secretion from Rat Islets Maintained in a Tissue Culture-Perifusion System

“…This phenomenon has been observed previously by Frankel et al, 8 who used a static culture system, and Rabinovitch et al, 9 who used static cultures subsequently transferred to a perifusion system for study. The cause for this decrease in secretory rate of insulin from cultured islets is unknown.…”

Cyclic Adenosine-3′,5′ -monophosphate Stimulates Islet B Cell Replication in Neonatal Rat Pancreatic Monolayer Cultures

“…Measurement of cAMP levels in the cultures revealed dissociations between effects on B cell replication and insulin release. Thus, addition of 0.1 mM IBMX, or 0.1 nM cholera toxin, to 5.6 mM glucose produced slightly greater increases in cAMP levels and B cell replication than did 16.7 mM glucose, whereas insulin release was increased significantly more with 16 (15-20 mM) has been shown to increase glucose metabolism (1, 2), insulin release and content (3)(4)(5)(6), and insulin biosynthesis (7), and also to improve the survival (6) and to stimulate the replication (8)(9)(10)(11) of islet B cells. Glucose has also been reported to stimulate adenylate cyclase (5,12) and to increase cyclic adenosine-3',5'-monophosphate (cAMP) levels (13) Green ancd Taylor (26).…”

Collagenase Isolation and ⁴⁵Ca Efflux Studies of Human Islets of Langerhans

“…The yield obtained with present methods for islet isolation is therefore insuffi cient for healing diabetes by transplantation. Previous investigations have suggested two possible ways to circumvent the problem of the low yield; the use of several donors and long-term storage [7,9,20,24] or repeated transplantation [18]. The separation of pancreatic islets from collagenasedigested pancreas by sedimentation through Percoll at unit gravity might also obviate the problem of the low yield; this method by its simplicity being suitable for large-scale islet isolation [5].…”

“…18-24 h elapsed between islet isola tion and the efflux experiments. Since during this time the islets were stored at room temperature or in a refrigerator, they were allowed to recover at 37 °C for 2-4 h [9] before the experiments.…”