Endocrine activities of ghrelin, a natural growth hormone secretagogue (GHS), in humans: Comparison and interactions with hexarelin, a nonnatural peptidyl GHS, and GH-releasing hormone. - Arvat,E.; Maccario,M.; di Vito,L.; Broglio,F.; Benso,A.; Gottero,C. (J Clin Endocrinol Metab, 2001)