Читать книгу Essential Endocrinology and Diabetes - Richard I. G. Holt - Страница 56

Historical experiments used radiolabelled hormones and isolated preparations of receptors to define two properties of binding (Box 3.2). The hormone–receptor interaction is both saturable (Figure 3.3) and reversible (Figure 3.4).

Using methodology similar to that for immunoassays (Chapter 4), constant amounts of labelled hormone and receptor preparations can be incubated with increasing, known amounts of unlabelled hormone for a specified time. Separating and measuring the receptor‐bound, labelled fraction allows curves to be plotted and mathematical modelling of the hormone (H)–receptor (R) interaction; e.g. whether it conforms to the equation H + R ⇆ HR. These types of experiment can also allow estimation of the number of hormone receptors present on each target cell.