Analysis of Ionomic Profiles of Canine Hairs Exposed to Lipopolysaccharide (LPS)-Induced Stress.

The purpose of this study was to provide a new insight on the response of canines to stress exposure; the ionomic profiles of canine hair (2.8 ± 0.3 years, 15.17 ± 2.1 kg) (n = 10) was determined before and after lipopolysaccharide (LPS) injections. LPS was intramuscularly injected to induce inflammatory stress responses which were confirmed by observing increases in the level of serum cortisol, aldosterone, and inflammatory cytokines such as IL-6, IL-1ß, and TNF-α. The hair contents of 17 elements were obtained by applying analytical procedures using the inductively coupled plasma mass spectrometry (ICP-MS). The following elements: sodium(Na) and potassium(K) among macro-elements, iron(Fe) and manganese(Mn) among micro-elements, and aluminum(Al), nickel(Ni), and lead(Pb) for toxic elements, showed significant increased levels with the immunological stress. The degree of increase in toxic elements was remarkable with the stress exposure. A forty-five-fold increase seen in Al accumulation with the stress exposure was noteworthy. Although mercury(Hg) and cadmium(Cd) showed decreased levels with the stress exposure, the degree was negligible compared to the level of increase. Correlation pattern between the elements was changed with the immunological stress. Toxic elements became more correlated with macro- or micro-elements than with toxic elements themselves after the stress exposure. Principal component analysis (PCA) showed that LPS challenge shifted the overall hair mineral profiles to a consistent direction changing Al and K up, even in animals with different hair mineral profiles before LPS treatment. In conclusion, the multivariate data processing and study of element distribution patterns provided new information about the ionomic response of the canine hairs to immunological stress, i.e., the ionomic profiles of canine hairs is strongly affected by the stress induced by LPS injections.

Effects of seasonal differences in testosterone and cortisol levels on pain responses under resting and anxiety conditions.

PURPOSE: This study investigated whether hormones and pain perception are associated with exam anxiety, and also whether exam anxiety is affected by seasonal differences in testosterone and cortisol levels. MATERIALS AND METHODS: Forty-six healthy males were recruited from a medical college. Anxiety was induced by having participants perform the Objective Structured Clinical Examination. Pressure was applied to the participants to induce pain. Pain thresholds, pain ratings, anxiety ratings, blood pressure, heart rate, salivary testosterone and cortisol levels were measured under resting and anxiety conditions in the spring and summer. Data were collected from 46 participants during the spring (n=25) and summer (n=21). RESULTS: Pain thresholds and testosterone levels were significantly lower under anxiety than at rest for all participants (n=46), while cortisol levels, pain ratings, and anxiety ratings were significantly higher under anxiety than at rest. In the spring (n=25), testosterone levels were significantly higher at rest than under anxiety, while there was no difference in cortisol levels between resting and anxiety conditions. In the summer (n=21), cortisol levels were significantly higher under anxiety than at rest, while there was no difference in testosterone levels between resting and anxiety conditions. There were no significant seasonal differences in pain and anxiety ratings and pain threshold. CONCLUSION: These results indicate that seasonal differences in testosterone and cortisol levels under anxiety and at rest may affect pain responses. These results also suggest that acute clinical pain may be relieved by managing anxiety that is related to a decrease of testosterone in spring and a large increase of cortisol in summer.