Central and Peripheral Actions of Calcitonin Gene-Related Peptide on Gastric Secretory and Motor Function

Abstract

Calcitonin gene related peptide (CGRP) was one of the first examples of a biologically active peptide to be identified by recombinant DNA and molecular biological approach (Rosenfeld et al., 1983; Amara et al., 1985). It was also the first demonstration of tissue-specific alternative processing of a gene. In 1983, Rosenfeld et al. initially reported that the RNA transcript from the calcitonin gene is processed in rat central and peripheral neural tissues to a mRNA encoding the precursor to a previously unknown 37-residue peptide called CGRP or α-CGRP (Rosenfeld et al., 1983). In thyroidal cells, the calcitonin gene generates a mRNA which encodes a calcitonin precursor protein expressing the calcium-regulating hormone, calcitonin (Rosenfeld et al., 1983). Subsequently, both intra- and interspecies variants have been discovered. A second calcitonin gene generating a mRNA expressing β-CGRP or CGRP II was identified in rats (Amara et al., 1985). Rat β and α forms differ in only one amino acid residue at position 35. The same mechanism of specific alternate RNA processing was described in human tissue.