A cDNA clone for type III adenylyl cyclase was originally isolated from a rat olfactory cDNA library and Northern analysis using total RNA suggested that the expression of the type III mRNA may be limited to the olfactory epithelium (Bakalyar and Reed, Science, 250 (1990) 1403-1406). In this study, the distribution of type III adenylyl cyclase mRNA in a number of bovine tissues and cultured cells was examined by Northern analysis using poly(A)+ RNA. Type III adenylyl cyclase mRNA was expressed in brain, spinal cord, adrenal medulla, adrenal cortex, heart atrium, aorta, lung, retina, 293 cells and PC-12 cells. Furthermore, the Ca2+ sensitivity of adenylyl cyclase activity in 293 cells indicated the presence of type III adenylyl cyclase. These data indicate that expression of the type III adenylyl cyclase is not limited to olfactory tissues, and that this enzyme probably has a number of physiological functions in addition to olfactory signal transduction.