Effect of constant light and immobilization stress on rat submandibular saliva secretory response induced by cholinergic and peptidergic agonists.

  • Raquel Gallará Universidad Nacional de Córdoba. Facultad de Odontología. Departamento de Biología Oral. Córdoba
  • Rubén Ponce Universidad Nacional de Córdoba. Facultad de Odontología. Departamento de Biología Oral. Córdoba
  • Viviana Centeno Universidad Nacional de Córdoba. Facultad de Odontología. Departamento de Biología Oral. Córdoba
  • Salvador Bellavía Universidad Nacional de Córdoba. Facultad de Odontología. Departamento de Biología Oral. Córdoba

Abstract

The aim of this work was to analyse the parasympathetic control of submandibular saliva secretory response to cholinergic and peptidergic agonists in rats chronically exposed to constant light or repeated immobilization. Thirty two adult male Wistar rats were used: LL (8 rats exposed to constant light for 20 days), IMO (8 rats submitted to 14:10 h light: dark cycle and immobilized 2 hours daily for 7 days), and control (16 rats not exposed to stress and submitted to 14:10 hours light:dark cycle). Saliva was collected under anesthesia from the salivary ducts of submandibular glands under increasing doses  of methacholine and substance P. Secretory responses (μg/saliva/mg dry weight gland) to methacholine were significantly higher in LL and IMO groups compared to control for the following doses (μg/kg  body weight): 3 (153±9 versus 46±3, p<0.001 and 76±3 versus 40±3, p<0.001), 10 (379±23 versus 277±8, p<0.001 and 275±19 versus 250±10, p<0.01) and 30 (729±25 versus 695±19, p<0.05 and 1008±39 versus 640±20, p<0.001). Also, responses to substance P were significantly increased in LL and IMO groups compared to control for the following doses: 0.2 (80±3 versus 30±3, p<0.01 and 94±16 versus 31±3, p<0.001), 0.5 (328±20 versus 231±16, p<0.01 and 531±31 versus 219±25,p<0.001), 1 (681±35 versus 547±30, p<0.01 and 1031±63 versus 563±53, p<0.001), and 5 (2222±88 versus 1868±59, p<0.01 and 3230±145 versus 1921±218, p<0.001). In conclusion, supersensitivity of secretory response to both agonists suggests that chronic exposure of rats to stressors capable of activating the sympathetic adrenal system promotes inhibition of the parasympathetic control of salivary secretion.

References

1. Proctor GB. The physiology of salivary secretion. Periodontol 2000. 2016;70(1):11–25.
2. Dawes C, Pedersen AM, Villa A, Ekström J, Proctor GB, Vissink A, Aframian D, McGowan R, Aliko A, Narayana N, Sia YW, Joshi RK, Jensen SB, Kerr AR, Wolff A. The functions of human saliva: A review sponsored by the World Workshop on Oral Medicine VI. Arch Oral Biol. 2015;60(6):863–74.
3. Reimer AE, de Oliveira AR, Diniz JB, Hoexter MQ, Chiavegatto S, Brandão ML. Rats with differential self-grooming expression in the elevated plus-maze do not differ in anxiety-related behaviors. Behav Brain Res. 2015;292:370–80.
4. Kvetnansky R, Lu X, Ziegler MG. Stress-triggered changes in peripheral catecholaminergic systems. Adv Pharmacol. 2013;68:359–97.
5. Gallara RV, Bellavia SL, Serova LL, Sabban EL. Environmental light conditions alter gene expression of rat catecholamine biosynthetic enzymes and Neuropeptide Y: differential effect in superior cervical ganglia and adrenal gland. Brain Res Mol Brain Res. 2004;124(2):152–8.
6. Alterman A, Mathison R, Coronel CE, Stroppa MM, Finkelberg AB, Gallará RV. Functional and proteomic analysis of submandibular saliva in rats exposed to chronic stress by immobilization or constant light. Arch Oral Biol. 2012;57(6):663–9.
7. Ross MJ, Guthrie P, Dumont JC. The impact of modulated, colored light on the autonomic nervous system. Adv Mind Body Med. 2013;27(4):7–16.
8. Lomo T. The Response of Denervated Muscle to Long-Term Stimulation (1985, Revisited here in 2014) Eur J Transl Myol. 2014;24(1):3294.
9. Tanev KS, Orr SP, Pace-Schott EF, Griffin M, Pitman RK, Resick PA. Positive Association Between Nightmares and Heart Rate Response to Loud Tones: Relationship to Parasympathetic Dysfunction in PTSD Nightmares. J Nerv Ment Dis. 2017;205(4):308–12.
10. Jarczok MN, Jarczok M, Mauss D, Koenig J, Herr RM, Thayer JF. Autonomic nervous system activity and workplace stressors--a systematic review. Neurosci Biobehav Rev. 2013;37(8):1810–23.
Published
2018-01-17
How to Cite
GALLARÁ, Raquel et al. Effect of constant light and immobilization stress on rat submandibular saliva secretory response induced by cholinergic and peptidergic agonists.. Journal of Oral Research, [S.l.], v. 7, n. 1, p. 16-19, jan. 2018. ISSN 0719-2479. Available at: <http://joralres.com/index.php/JOR/article/view/joralres.2018.008>. Date accessed: 25 may 2019. doi: https://doi.org/10.17126/joralres.2018.008.
Section
Communications

Keywords

submandibular gland; saliva; substance P; methacholine; adverse effects.