ABSTRACT
BACKGROUND: Nasal saline irrigation is a safe treatment for chronic rhinosinusitis; however, its effect on olfaction is unclear. Cyclic adenosine monophosphate (cAMP) is a key second messenger in the mechanism of olfaction and has been shown to be associated with smell function. In animal studies, olfactory cilia may be harvested by simple saline preparations. This study aimed to characterize the effect of nasal saline irrigation on smell function. METHODS: Volunteers with normal olfaction were randomized into a control or irrigation cohort. In the initial appointment, subjects completed a University of Pennsylvania Smell Identification Test (UPSIT) and nasal samples were obtained by 2 methods: the nasal curette and cytobrush. The irrigation cohort performed daily nasal saline irrigations. Both cohorts then returned in 1 week. The UPSIT and nasal cell collection were repeated, and each subject completed a subjective olfactory transition scale. Nasal samples were processed for cAMP levels using a commercial assay. RESULTS: Thirty-two subjects were enrolled and randomized into each cohort. Control and postirrigation mean UPSIT scores were 36.8 and 36.7 (p = 0.48). No subjects reported a subjective smell loss. Ten pairs of nasal samples were assayed. Using the curette, control and postirrigation cAMP levels were 509 and 490 fmol/(mg/mL), respectively (p = 0.94). Using the cytobrush, respective cAMP levels were 424 and 449 fmol/(mg/mL), respectively (p = 0.94). CONCLUSION: Nasal saline irrigation has no subjective or objective effect on olfaction. It also does not appear to affect cAMP levels, a potential marker of smell function.
Subject(s)
Cyclic AMP/metabolism , Nasal Cavity/drug effects , Nasal Lavage/adverse effects , Smell/drug effects , Sodium Chloride/adverse effects , Adult , Female , Humans , Male , Middle Aged , Nasal Lavage/methods , Prospective Studies , Treatment Outcome , Young AdultABSTRACT
Recently, human protein associated with MYC, PAM, has been cloned and characterized as a large protein that interacts with the transcriptional-activating domain of Myc. The regional expression pattern of PAM in brains has not been yet been defined. Expression patterns of PAM in both rat and mouse brains were examined by using in situ hybridization. Here, we demonstrate that PAM mRNA is highly expressed in specific anatomical regions including hippocampus, dentate gyrus and cerebellum. In these areas, PAM mRNA is restricted to pyramidal cells of hippocampus and granule cells of dentate gyrus and cerebellum. During development, PAM mRNA expression is differentially regulated. It is turned on after birth and up-regulated during the first postnatal 2 weeks. Thereafter, PAM mRNA expression remains elevated into adulthood. The regional distribution of PAM in brain is similar to that observed for several adenylyl cyclase isoforms such as type I isoform. However, no obvious alterations of PAM mRNA expression are detected in brains of mice deficient in type I or type 8 or type 1 and type 8 isoforms of adenylyl cyclase. Thus, adenylyl cyclase does not appear to alter the expression of PAM.
