TSH receptors in human thyroid tumours

To evaluate the binding of human TSH (h-TSH) to various human thyroid tumours using radio receptor assay technique, 26 thyroid tumour specimens were examined. Five specimens did not show displacement by stable h-TSH. A wide variation was observed in B0, non specific binding, affinity and capacity of TSH in all the tumours examined. The Scatchard analysis of the binding of h-TSH to thyroid membranes suggested the presence of the receptors in 57.7 per cent (15 of 26, Ka much greater than 10(9)) and more than one component in 46 per cent (12 of 26) of the tumours studied. There was no consistent pattern of the binding of TSH for thyroid tissue with respect to its pathology. However, with 35 pairs of observations log affinity appeared to be linearly related to log capacity with a slope -0.95, intercept 9.96 and r value -0.93.