Plasma galanin, vasopressin, and oxytocin in patients with Addison's disease

Galanin is colocalized with adrenocorticotrophin (ACTH) in the human pituitary and with corticotrophin releasing hormone, arginine, vasopressin, and oxytocin in the hypothalamus. Galanin, vasopressin, and oxytocin influence the secretion of pituitary ACTH. The aim of this study was to investigate if the endogenous stimulation of ACTH release in Addison's disease was reflected in plasma galanin, vasopressin, and oxytocin. ACTH, galanin, vasopressin, and oxytocin were measured in plasma from 14 patients with Addison's disease, one patient with Nelson's syndrome, and 14 healthy controls. Eight patients had elevated plasma ACTH whereas six patients and all controls had ACTH levels within the reference-range. There was no difference in galanin or vasopressin between patients and controls or between samples with low or high ACTH concentrations. In contrast, oxytocin was higher in patients with elevated plasma ACTH compared to patients and controls with normal or low ACTH. No relation was found between galanin or oxytocin and age or sex. A tendency towards lower vasopressin with increasing age was found among the men (p=0.057). The highest ACTH and galanin levels were found in the patient with Nelson's syndrome. In conclusion, increased plasma ACTH was not reflected in elevated plasma galanin or vasopressin. In contrast, elevated ACTH levels were accompanied by higher oxytocin levels.