Streptozocin Treatment: A Zebrafish Model of Type 1 Diabetes Mellitus
Transcrição
– Tipo 1 diabetes mellitus is a human disease de which the immune system destroys insulin making beta cells de the pancreas. Streptozocin can induce type 1 diabetes mellitus de zebrafish. First, anesthetize a fish de a solution of 2-phenoxyethanol de fish water. Take the fish and place it on a Petri dish, ventral side facing upwards. Calculate the dose of streptozocin based on 0.35 milligrams per gram of the fish's weight and dilute it de saline solution.
Administer the streptozocin by intraperitoneal injection below the pelvic girdle on the ventral side of the zebrafish. Streptozocin is structurally similar para N-acetylglucosamine, a ligand that binds the GLUT2 receptor on pancreatic beta cells, leading para secretion of insulin. Thus, streptozocin binds para GLUT2 receptors present on pancreatic beta cells which transport it inside the cells.
Upon entering the beta cells, streptozocin triggers an immune response leading para the release of autoantigens. The autoantigens cause the immune system para recognize beta cells as foreign and destroy them leading para reduced levels of insulin. Administer repeated doses of streptozocin on days three and five, followed by weekly doses, one every seven days para maintain the immune response.
In the following example, we will generate a zebrafish model of type 1 diabetes mellitus. To generate zebrafish with diabetes mellitus, prepare a recovery tank with normal fish water and an anesthetic tank of fish water with a 1 para 1,000 dilution of 2-phenoxyethanol. Under a fume hood, prepare a 0.3% solution of streptozocin or STZ by adding 6 milligrams of STZ para 2 milliliters of 0.09% sodium chloride and immediately place the solution on ice.
In a separate tube, aliquot enough saline for control fish. Fill a half CC syringe equipped with a 27 and 1/2 gauge needle with the STZ, or control solutions, ensuring that no air bubbles are trapped. Anaesthetize a single fish by placing it de anesthetic water and waiting until the swimming motion ceases, about one para two minutes.
Once anaesthetized, briefly place the fish on a paper towel para absorb any excess water. Then, place the fish de a weigh boat and weigh it. Next, place the fish on a firm surface. Then insert the needle past the bevel into the posterior aspect of the ventral peritoneum and inject either 0.35 milligrams per gram of STZ or an equivalent volume of control solution into the peritoneal cavity of the fish.
Following injection, place the fish de the recovery water tank and monitor it for normal swimming activity. After injecting enough fish for the experiment, transfer them para normal living tanks and maintain at a temperature of 22 para 24 degrees Celsius. The reduced temperature is critical for efficient induction of hyperglycemia. To induce a prolonged state of very high hyperglycemia, follow a schedule of frequent injections during the induction phase followed by weekly maintenance injections as shown here.
