Immunoreactive Corticotropin-Releasing Hormone, Growth Hormone-Releasing Hormone, Somatostatin, and Peptide Histidine Methionine Are Present in Adrenal Pheochromocytomas, but not in Extra-adrenal Pheochromocytoma*

Abstract

CRH, GH-releasing hormone (GHRH), somatostatin (SRIH), and peptide histidine methionine (PHM) were measured by RIA in extracts of normal adrenal glands and in extracts from adrenal and extraadrenal pheochromocytomas. In normal adrenal glands, immunoreactive (IR) CRH, IR-SRIH, and IR-PHM were detectable, while IR-GHRH was undetectable. In all 11 cases of adrenal pheochromocytomas, the tumors contained 2 or more of these four IR-peptides. In particular, IR-CRH was found in 73% (n = 8) of adrenal pheochromocytomas, IR-GHRH in 91% (n = 10), IR-SRIH in 91% (n = 10), and IR-PHM in 82% (n = 9) of adrenal pheochromocytomas. There was no significant correlation among the concentration of these peptides in each tumor, i.e. the concentrations of the IR-peptides were independent of each other. In contrast to the adrenal pheochromocytomas, none of these 4 IR-peptides was detectable in 5 extraadrenal pheochromocytomas. Gel filtration of pooled extracts from adrenal pheochromocytomas showed that the major component of the IR-CRH, IR-GHRH, IR-SRIH, and IR-PHM eluted in the position of their synthetic counterparts. Our results suggest that 1) the normal adrenal gland contains IR-CRH, IR-SRIH, and IR-PHM, but not IR-GHRH; 2) all of the adrenal pheochromocytomas we examined contained a number of hypothalamic releasing or inhibiting hormones; 3) their tissue concentrations were independent of each other; and 4) all of the extraadrenal pheochromocytomas we examined contained no such IR-peptides. The presence of hypothalamic hormones in adrenal pheochromocytomas and their absence in extraadrenal pheochromocytomas may be due to the differences in the chromaffin cells of their origin. Our data may be helpful in the differential diagnosis between adrenal and extraadrenal pheochromocytomas.