FK-506 is a
It is a macrolide antibiotic FK-506 is commonly known as Tacrolimus. Tacrolimus is a macrolide antibiotic produced by streptomyces tsukubaensis. Tacrolimus acts as imnmunosuppressant by acting against calcineurin. The other calcineurin inhibitor is cyclosporine. Calcineurin inhibitors Calcineurin inhibitors are perhaps the most effective immuno-suppressive drugs in routine use. Role of calcineurin Calcineurin acts as a intracellular signal transductor. Once the T cell receptors are activated, signals are sent to the nucleus through the calcineurin, for the transcription of cytokine genes. This leads to production of IL-2 along with other interleukins. Interleukin-2 and other cytokines leads to the proliferation of cellular and humoral immunity. Calcineurin inhibitors, inhibitins the calcineurin. Mechanism of action of cyclosporin Cyclosporin enters the target cells and binds to a cytoplasmic protein called cyclophilin --> the complex then binds to and inactivates calcineurin -- decreased production of IL-2 --)decreased immune response. Tacrolimus The mechanism of action is almost similar to cyclosporine. The slight difference is that it binds to different cycoplasnzic protein which is FKBP, but the subsequent steps are same i.e. inhibition of calcineurin --4 decreased production of IL-2 -1 decreased immune response. More on Tacrolimus It is 10 times more potent than cyclosporine. Because of more potent action it is also suitable for suppressing acute rejection that has set in. It is paiculary valuable in liver transplantation because its absorption is not dependent on bile. It has the same toxicity profile as cyclosporine.
>It is a macrolide antibiotic
>Immunoglobulin antibody
>Non depolarising muscle relaxant
>Opioid analgesic