Endorphins: endogenous substrates for dental analgesia?

An individual's pain threshold is a function of their endorphin level, which is regulated in a manner analagous to an automatic titering system. The transient duration of the analgesic effect is due specifically to three hydrolases. These enzymes can be inhibited by a number of peptides which can prolong and, even of themselves, provide some degree of analgesia. The challenge is to develop an acute carboxypeptidase inhibitor with a high Km, no toxicity, limited biological half-life and the ability to cross the blood-brain barrier. The clinical implications of such a compound are incredible. The induced analgesic effect is essentially a direct function of the patient's endorphin levels, i.e., the greater the degrees of stress, the more efficacious a given amount of enzyme inhibition would become. This type of drug appears to be an ideal adjunct for current dental therapeutics as its effect is precisely titered to the patient's degree of need. In conclusion, a review of endorphin-associated physiological processes suggests a cornucopia of therapeutic implications.