Specific 5α-Dihydrotestosterone Receptors in Human Gingiva

Abstract

The cytoplasm of normal human male and female gingiva contains a receptor capable of specifically binding 5α-dihydrotestosterone (DHT). This binding has a high affinity for DHT (K_d, ~2.2 × 10⁻⁹ M) and a low capacity (~190 fmol/mg protein). The binding is extremely heat sensitive and exhibits a pattern of competition similar to that obtained with DHT receptors from other target tissues. The demonstration of a specific DHT receptor in human gingiva provides the first direct biochemical evidence that this tissue may function as a target organ for androgens. There was no correlation between the K_d in normal tissue and gingival hyperplasia or between the K_d or number of binding sites and the age or sex of the patient. However, there was a significant difference (P < 0.0005) between the amount of DHT-binding sites per mg protein in normal tissue as compared to gingival hyperplasia (drugs or pregnancy).