E0030151

metadata only access

Not Applicable (or Unknown)

スイトウ イショク ニヨル トウニョウビョウ チリョウ ニカンスル キソテキ ケンキュウ : トクニ スイトウ ソシキ ホゾンホウ ノ ケントウ

Basic studies on pancreatic transplantation for reversal of diabetes : preservation of pancreatic islets

Japanese (日本語)

Medical journal of Kobe University

45(4)

595-605

1984-06

Transplantation of pancreatic tissues has been recognized as one of the radical therapeutic measurements for insulin-dependent diabetes. Therefore, prior preservation of the tissues to transplantation in diabetics is desired to accumulate their sufficient number and match histocompatibility. In the present study the cryopreservation of pancreatic tissues and islets was evaluated in terms of insulin release and synthesis and protein synthesis. Moreover, an intraperitoneal allotransplantation of frozen-thawed pancreatic tissues was studied in streptozotocin-induced diabetic rats. Syrian golden hamster insulinoma cells (In-lll cells) were cultured in RPMI-1640 for 2 days. In the absence and presence of 1.3 mM theophylline, insulin released were 1.42±0.11 and 4.09±0.29ng/10^6 cells 2 days, respectively. These cells after immersion in 10% dimethylsulfoxide (Me_2S0) were program-frozen to -80℃ at a cooling rate of 1℃/min or 0.5℃/min to -40℃ subsequently at 3℃/min to -80℃ with a program-freezer. Insulin released from these frozen-thawed cells were 2.81±0.23 and 10.91±1.05ng/10^6 cells 2 days at the cooling rate of 1℃/min, and 4.18±0.31 and 16,77±0.78ng/10^6 cells 2 days at 0.5℃/min in the absence and presence of 1.3mM theophylline, respectively. At both cooling rates the insulin release was enhanced significantly in the presence of theophylline compared with that in its absence. Frozen-thawed rat pancreatic islets released extraordinarily abundunt insulin even in 3.3 mM glucose compared with non-frozen islets. However, the additional procedures of pre-freezing and post-thawing culture as well as stepwise dilution of Me2SO lowered this enormous insulin release down to the level induced by the non-frozen islets. Furthermore, the islets after these procedures released 1.6 times as much insulin in the presence of 16.7mM glucose as in 3.3mM glucose. Frozen-thawed pancreatic tissues and isolated islets were incubated with 3H-Ieucine for 2 hours. 3^H-Ieucine incorporations into perchloric acid precipitable and anti-insulin antibody-polyethyleneglycol precipitable fractions in both types of the preparations were not different from those of the corresponding non-frozen controls. Therefore. it was suggested that protein and insulin biosynthesis of frozen-thawed tisssues and islets were not impared by the present freezing-thawing procedure. The streptozotocin-induced diabetic rats with fasting plasma glucose of 477.4±34.1mg/dl showed the significant reduction of the glucose level to 262.7±32.8 and 286.0±41.4mg/dl 1 week and 4weeks after the intraperitoneal transplantation of frozen-thawed pancreatic tissues, respectively. From the present investigation the slow cooling rate seemed to be favourable for the maintenance of pancreatic endocrine cell function. However, even at such cooling rate the islet cell function of insulin release was still defective. And it was indicated that pre-freezig, post-thawing culture and stepwise dilution of cryoprotective agent were useful for maintenance of not only secretory but also biosynthetic function. Since a perfect maintenance of the pancreatic tissue function was not yet obtained in the present procedure albeit the requirement of a long-term cryopreservation of the tissue, further investigations on the more sophisticated method of the preservation are needed to establish the pancreatic transplantation for the radical treatment of clinical diabetes.

pancreatic islets

紀要論文