[The endogenous allosteric regulators of receptors]

The literature data devoted to endogenous allosteric regulators of membrane bound receptors are summarized in the present review. The allosteric processes are classified to (i) cooperative interaction, (ii) nonspecific, (iii) functional, and (iv) specific regulations according to target topography in a receptor. The specific endogenous allosteric regulators are described for GABAA, NMDA, muscarinic, nicotinic, serotonin, and opioid receptors. Substances of different chemical structure (peptides, lipids, and polycyclics) are able both to activate or inhibit binding and function of respective receptors. Some pathological processes appear to depend on endogenous receptor modulators. The role of the regulators is speculated in terms of receptor homeostasis, in particular, counteraction of receptor tolerance and/or sensitisation during physiological pulsation in a ligand' level in synaptic cleft.