Robert J. Kemppainen, DVM, PhD

To understand the mechanism for glucocorticoid negative feedback regulation of ACTH secretion. We have identified a gene, Dexras1, that is rapidly up-regulated in pituitary in response to glucocorticoids and are trying to determine its role in mediating steroid feedback. Clones overexpressing Dexras1 and mutant forms are evaluated for ACTH secretion. In addition, RNAi and other methods are used to selectively reduce Dexras1 expression in response to glucocorticoids to assess the effect of its removal.

Also serves as Director of the Endocrine Diagnostic Service, located in the Department. Provides hormone testing for veterinarians in practice. Research in this area include development of improved methods to diagnose endocrine disease in dogs and cats.

Basic Research:

Kemppainen RJ, Cox E, Behrend EN, Brogan MD, Ammons JM. Identification of a glucocorticoid response element in the 3-flanking region of the human Dexras1 gene. Biochimica et Biophysica Acta 1627:85-89, 2003.

Brogan MD, Behrend EN, Kemppainen RJ. Regulation of Dexras1 expression by endogenous steroids. Neuroendocrinology 74:244-250, 2001.

Kemppainen RJ, Behrend EN. Dexamethasone rapidly induces a novel RAS superfamily member-related gene in AtT-20 cells. Journal of Biological Chemistry 273:3129-3131, 1998.

Clinical Research:

Behrend EN, Kemppainen RJ, Bruyette DS, Busch KA. Intramuscular administration of a low dose of ACTH for ACTH stimulation testing in dogs. JAVMA 229:528-530, 2006.

Kemppainen RJ, Birchfield JR. Measurement of total T4 concentration in serum from dogs and cats by use of various methods. American Journal of Veterinary Research 67:259-265, 2006.

Kemppainen RJ, Behrend EN, Busch KA. Use of compounded adrenocorticotropic hormone (ACTH) for adrenal function testing in dogs. Journal of the American Animal Hospital Association 41:368-372, 2005.