The Effects of Photobiomodulation Therapy on Porcine Islet Insulin Secretion

Xenotransplantation of porcine islets to human recipients has been investigated as a potential cure for type 1 diabetes. However, the porcine islets have poor insulin secretion capacity compared with human islets. The objective of this study was to evaluate the effect of photobiomodulation therapy (PBMT) in insulin secretion on isolated porcine islets. Eight pancreata were harvested from crossbred market porcine and the islets were isolated from the pancreas. The isolated islets were treated with PBMT (wavelength: 633 nm and dosages: 0.0, 15.6, and 31.3 J/cm²) followed by 30-min incubation in low (3.0 mM) or high (16.7 mM) glucose. The relative percentage differences on insulin secretion between three dosages were compared in low and high glucose, respectively. Insulin secretion was higher in samples exposed to 15.6 J/cm² PBMT in low glucose (p < 0.05), but not in high glucose. When evaluating sex differences, male islets had higher insulin secretion by 15.6 J/cm² PBMT in low glucose compared with females (p < 0.05). No significant differences were seen in high glucose. When compared within the control groups (0.0 J/cm² PBMT), the relative changes on insulin secretion in high glucose was significantly higher on male islets (p < 0.05), but not on female islets. PBMT may increase insulin secretion on isolated porcine islets in basal condition, but it may not improve islets' glucose responsiveness to secrete insulin. Male porcine islets may respond to PBMT and glucose stimuli better than female islets on insulin secretion.