Receptor structure and function: an exploratory approach using the thyrotropin receptor as a vehicle.

The purpose of this chapter is not to present the final or even correct model of TSH receptor structure and function. Rather, the current speculative model presented is used to open the door to a more broad view of the receptor problem and controversy as it has evolved today. Questions of how we define a receptor are clearly very much in flux and much more difficult than initially considered when a chemical approach is taken. Numerous binding components will be described and their relevance to the physiologic state will be debated. Some will be clearly erroneous in concept--yet the very debate and data will open new ideas and approaches other than repetitive membrane binding or response measurements. The remainder of this book will explore numerous other aspects of receptor structure, regulation and function. The reader may be disturbed by the complexity and extrapolations of data and the weakness of the models. The reader should, however, remember that the receptor is the key link of the cell to its environment. The complexities of this linkage are evident in our continued concern with knowledge of the mechanisms our bodily senses utilize. The controversy that will exist is evident in the arguments we have today over the agents in our environment which affect us and the mechanisms of these effects. It is hoped that this chapter and book will provide both the desire and some reference to follow and review the data in all receptor fields as they emerge in the next several years.