Chromogranin a epitopes catestatin and vasostatin

Abstract: Psychological and physiological factors, including pain, can induce a stress response. All today’s available methods for evaluating stress in dogs have shortcomings and it is therefore necessary to identify and evaluate new biomarkers. Chromogranin A (CgA) is a useful biomarker for stress assessment in humans. In dogs, the CgA epitopes catestatin (CST) and vasostatin (VS) can be measured. This thesis aimed to evaluate the potential use of the CgA epitopes CST and VS as biomarkers for psychological and pain-induced stress in dogs in a clinical setting. Reference ranges of plasma CST, VS, and saliva CST concentrations in healthy low-stressed dogs were determined. Age, gender, breed, and time of day did not significantly affect CST and VS concentrations. CST and VS were evaluated as biomarkers for psychological stress. CST and VS in associated with other stress evaluation methods were compared in healthy dogs where one group was stressed and the other was not. In the stress group, saliva CST, serum cortisol, and stress scores increased significantly and saliva CST did not overlap with the reference range. Plasma CST and VS did not change significantly. CST and VS were further tested as biomarkers for pain-induced stress by comparing the concentrations in different surgical settings. CST, VS, and other pain and stress monitoring methods were investigated in healthy dogs that received analgesia and were subjected to elective ovariohysterectomy. Compared with before surgery, plasma CST decreased significantly during anesthetic recovery and at recall for suture removal and serum cortisol decreased significantly at recall, suggesting that CST may be a possible pain-induced stress biomarker. CST and VS were measured in dogs with fractures prior to and after morphine treatment and evaluated in association with other pain and stress evaluation methods and compared with control dogs. Circulating CST and cortisol decreased significantly in dogs with fractures, but did not differ significantly between before and after morphine analgesia. Plasma CST overlapped with the reference ranges but plasma VS did not differ significantly throughout the studies. In conclusion, saliva CST may have potential as a psychological stress biomarker in dogs. Repeated sampling of plasma CST may be of interest for evaluating pain within the same patient. Plasma VS has no potential as a stress biomarker in dogs.