Thyroid stimulating hormone test kit EIAgen

for thyroid diseasesalbuminglobulin

The EIAgen U-TSH Kit has been designed for the quantitative determination of human Thyroid Stimulating Hormone (TSH) in human serum or plasma. The standards are calibrated against WHO 2nd International Reference Preparation (IRP) for human TSH (80/558) (1). Introduction Thyroid-stimulating hormone (TSH), or thyrotrophin, is a glycoprotein with a molecular weight of about 28,000 secreted by the pituitary gland. TSH is composed of two subunits of approximately equal size, called a and b. Other hormones such as luteinizing hormone (lH) and follicle-stimulating hormone (FSH), both secreted by the pituitary, and chorionic gonadotrophin (hCG), produced by the placenta, have a subunits virtually identical to that of TSH, but there are important differences in their b subunits (2). These differences confer biological specificity on the complete molecules and allow them to be distinguished in immunoassays. Like the other glycoprotein hormones, TSH has a specific site of action which is the thyroid gland. Its main function is to regulate the release of thyroxine (T4) and the more biologically active triiodothyronine (T3), and to control different stages of their synthesis (4). These thyroid hormones circulate bound to thyroxine-binding globulin (TBG) and to a lesser extent, to albumin and pre-albumin. In their unbound form, they have widespread effects on other organ systems of the body, exerting a general control on the level of metabolic activity (6). They also exert negative feedback on the pituitary, inhibiting the release of TSH. Synthesis and release of TSH is stimulated by thyrotrophin-releasing hormone (TRH).