Modulatory effects of calcitonin gene-related peptide and substance P on human cholinergic sweat secretion

Immunoreactivity to various peptides has been demonstrated in nerve terminals around the sweat glands, suggesting a regulatory function for these peptides on sweating. The present study evaluated the calcitonin-gene related peptide and substance P related regulation of sweating in man. Both calcitonin-gene related peptide and substance P, when administered alone, failed to cause sweat secretion, whereas sweating induced by methacholine chloride alone was four times greater when administered with calcitonin-gene related peptide and suppressed by 70% when administered with substance P. The degree of calcitonin-gene related peptide dependent augmentation and substance P dependent suppression of the methacholine chloride induced sweating was dependent on the concentration of calcitonin-gene related peptide and substance P. These findings suggest that calcitonin-gene related peptide enhances cholinergic sweating and substance P inhibits it.