Relationship between salivary Chromogranin-A and stress induced by simulated monotonous driving

Abstract

Abstract:The purpose of the present study was to evaluate the use of salivary Chromogranin-A (CgA), which is already used in general as a mental stress marker, for studying the stressful situation created by simulated monotonous driving. After informed consent 25 healthy male & female subjects were studied, under constant environment-controlled conditions. We measured the following physiological variables: blood pressure (BP), cardiac output (CO), total peripheral resistance (TPR), normalized pulse volume (NPV) as an index of alpha-adrenergic sympathetic activity to the finger arteriolar vessels, levels of cortisol and CgA during monotonous driving. The induced stress led to the expected decreases in NPV and increases in TPR and BP caused by peripherally-related sympathetic acceleration. However, CgA levels were found to fall gradually in accordance with the gradual increase of subjective rating of stress (SRS) and significantly (p<0.01) decreased over the period of the simulated monotonous driving.Our hypothesis for the gradual decrease of CgA levels during the simulated monotonous driving is as follows. CgA, catestatin and Catecholamines are co-released into the extra-cellular environment. Peripheral sympathetic activity was accelerated by stress resulting from the simulated monotonous driving. Upon peripheral vessel constriction, an increase in total peripheral resistance (TPR) then increased BP which, in turn, activated catestatin. Consequently, secretion of CgA was blocked by the co-secreted catestatin from chromaffin granules. The results obtained strongly indicate that, although CgA has been reported as a possible marker of stress, CgA levels are not increased in the stressful situation of simulated monotonous driving.

Salivary Hormones, Immunes and Other Secretory Substances as Possible Stress Biomarker

“…However some studies showed inconsistent results (e.g., Yamakoshi, 2009). It might attributes to the nature of high "temporal sensitivity" of CgA against a mild stressor illustrated in our study.…”

“…CgA has been reported to transiently increase in response to short-term laboratory stressors such as a calculation test (Nakane, 1999), white noise (Miyakawa, 2006), and a cognitive task (Kanamaru, 2006). On the other hand there are studies failed to observe increase or rather decrease against a laboratory stressors (e.g., Yamakoshi, 2009) and observed a transient increase in subjects who declared the positive affection after watching a comic video (Toda, 2007).…”

Salivary markers of inflammation in response to acute stress

“…For example, salivary alpha amylase (sAA), which appears to capture components of sympathetic nervous system activity (Nater et al, 2005), is not reviewed; its role in response to stress has been reviewed separately elsewhere (Granger et al, 2007). Studies measuring salivary immunoglobulin A (sIgA), which plays an important role in mucosal immunity (Tsujita & Morimoto, 1999), and neuroendocrine markers like chromogranin A (CgA; Kanamaru et al, 2006; Yamakoshi et al, 2009) are also not reviewed here; biomarkers such as sAA, sIgA, and CgA are relevant to inflammation in the sense that the endocrine and sympathetic nervous systems are connected to the immune system, but are not themselves direct measures of inflammation (Nater & Rohleder, 2009). …”

Controlled mechanical vibration applied to driver’s right heel to sustain alertness: Effects on cardiovascular behavior

“…That is, all conditions exhibited the vascular-dominant reaction pattern, as indicated by the rise in TPR, which means that vasoconstriction occurred. In fact, this passive coping is a distinctive response in monotonous driving situations (Yamakoshi et al, 2013;Yamakoshi et al, 2009a;Yamakoshi et al, 2009b). However, compared with the two controls, MBP and TPR elevation is inhibited in 20Hz.…”

“…Driving tests were performed using a driving simulator, which had previously been constructed at Kanazawa University and validated in terms of usefulness as a simulator (Yamakoshi et al, 2009a;Yamakoshi et al, 2009b). The simulator consists of an adjustable car seat, steering wheel, gear lever, clutch, brake, and accelerator pedals for vehicle control.…”