CLASSIFICATION AND NOMENCLATURE OF SOMATOSTATIN RECEPTORS

There is considerable controversy about the classification acid nomenc lature of somatostatin receptors. To date, five distinct receptor gene s have been cloned and named chronologically according to their respec tive publication dates, but two were unfortunately given the same appe llation (SSTR(4)). Consensually, a nomenclature for the recombinant re ceptors has been agreed according to IUPHAR guidelines (sst(1), sst(2) , sst(3), sst(4) and sst(5)). However, a more informative classificati on is to be preferred for the future, employing all classification cri teria in an integrated scheme. It is already apparent that the five re combinant receptors fall into two classes or groups, on the basis of n ot only structure but also pharmacological characteristics. One class (already referred to by some as SRIF(1)) appears to comprise sst(2), s st(3) and sst(5) receptor subtypes. The other class (SRIF(2)) appears to comprise the other two recombinant receptor subtypes (sst(1) and ss t(4)). This promising approach is discussed but it is acknowledged tha t much more data from endogenous receptors in whole tissues are needed before further recommendations on somatostatin receptor nomenclature can be made.