['Ghrelin and its receptor, growth hormone secretagogue (GHS) receptor (GHSR), are expressed in the normal pituitary gland and various types of pituitary adenoma. Somatic mutations in the subunit of Gs alpha protein (gsp), which led to a constitutive activation of adenylyl cyclase, are reported in GH-producing pituitary adenomas. We analysed the relationship between ghrelin mRNA and GHSR mRNA expression levels in gsp mutation-positive and -negative GH-producing pituitary adenomas.', 'Pituitary adenoma tissue was obtained at surgery from 20 patients with acromegaly.', 'The expression levels of human ghrelin mRNA and GHSR mRNA were quantified using a competitive RT-PCR method. To detect the gsp mutations, amplified Gs alpha subunit cDNA fragments were sequenced directly using RT-PCR method.', 'There was no significant difference in the expression of ghrelin mRNA between mutation-positive and -negative adenomas. The expression of GHSR mRNA was significantly lower in gsp mutation-positive than -negative adenomas. There was a significant negative correlation between the levels of ghrelin mRNA and GHSR mRNA expression in mutation-negative adenomas; no such correlation was found in mutation-positive adenomas.'] Is ghrelin mRNA and GH secretagogue receptor mRNA in human GH-producing pituitary adenomas affected by mutations in the alpha subunit of G protein?