Expression of growth hormone-releasing hormone (GHRH) and splice variant of GHRH receptors in normal mouse tissues

• Published in: Regulatory peptides Vol. 136; no. 1; pp. 105 - 108
• Main Authors: Christodoulou, C., Schally, A.V., Chatzistamou, I., Kondi-Pafiti, A., Lamnissou, K., Kouloheri, S., Kalofoutis, A., Kiaris, H.
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier B.V 11-09-2006; Amsterdam Elsevier
• Subjects: Alternative Splicing; Animals; Autocrine; Biological and medical sciences; Extrapituitary; Female; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation; GHRH; Growth Hormone-Releasing Hormone - biosynthesis; Immunohistochemistry; Mice; Mice, Inbred C3H; Mice, Inbred C57BL; Paracrine; Receptor; Receptors, Neuropeptide - biosynthesis; Receptors, Neuropeptide - genetics; Receptors, Pituitary Hormone-Regulating Hormone - biosynthesis; Receptors, Pituitary Hormone-Regulating Hormone - genetics; RNA, Messenger - metabolism; SV1; Tissue Distribution; Vertebrates: endocrinology; Paracrine; Extrapituitary; Autocrine; Receptor; GHRH; SV1; Alternative splicing; Somatotropin releasing factor; Rodentia; Somatotropin hormone; Hypothalamic hormone; Vertebrata; Mammalia; Adenohypophyseal hormone; Mouse; Animal; Hormone releasing factor; Biological receptor
• ISSN: 0167-0115; 1873-1686
• DOI: 10.1016/j.regpep.2006.05.001

Growth hormone-releasing hormone (GHRH) stimulates the production and release of growth hormone in the pituitary and induces cell proliferation in a variety of peripheral tissues and tumors. These extrapituitary effects of GHRH are in many cases mediated by a splice variant of GHRH receptor designated SV1 that differs from the pituitary GHRH receptor in a small portion of its amino-terminal region. While SV1 has been detected in several primary tumors and many cancer cell lines its expression in normal tissues remains unclear. In this study we report the results of an immunohistochemical analysis for SV1 and GHRH expression in normal mouse tissues. For the detection of SV1 immunoreactivity we used a polyclonal antiserum against segments 1–25 of the SV1 receptor protein. Mouse heart, colon, lungs, small intestine, stomach and kidneys exhibited increased SV1 immunoreactivity. These tissues were also positive for GHRH expression, however, tissues such as the endometrium were positive only for GHRH and not for SV1 expression. On the contrary, testis were positive for SV1 and not for GHRH expression. These results indicate that SV1 may play a role in normal physiology.