Fluidics system for resolving concentration-dependent effects of dissolved gases on tissue metabolism

Oxygen (O₂) and other dissolved gases such as the gasotransmitters H₂S, CO, and NO affect cell metabolism and function. To evaluate effects of dissolved gases on processes in tissue, we developed a fluidics system that controls dissolved gases while simultaneously measuring parameters of electron transport, metabolism, and secretory function. We use pancreatic islets, retina, and liver from rodents to highlight its ability to assess effects of O₂ and H₂S. Protocols aimed at emulating hypoxia-reperfusion conditions resolved a previously unrecognized transient spike in O₂ consumption rate (OCR) following replenishment of O₂, and tissue-specific recovery of OCR following hypoxia. The system revealed both inhibitory and stimulatory effects of H₂S on insulin secretion rate from isolated islets. The unique ability of this new system to quantify metabolic state and cell function in response to precise changes in dissolved gases provides a powerful platform for cell physiologists to study a wide range of disease states.