Effect of acute stress in masseter muscle in masticatory hypofunction

• Grant number: 11/18889-9
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): November 01, 2011
• Effective date (End): October 31, 2012
• Field of knowledge: Biological Sciences - Morphology - Anatomy
• Principal Investigator: Mamie Mizusaki Iyomasa
• Grantee: Fernanda Silva Fernandes
• Host Institution: Faculdade de Odontologia de Ribeirão Preto (FORP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

Clinical evidence has shown that physical and emotional stress may be associated with altered masticatory muscle function in subjects submitted to different daily situations. However, morphological changes in masticatory muscles induced by occlusal alteration and associated with emotional stress, is still scarce in the literature. The objective of this work is to evaluate the hypothesis that acute stress affects the morphology and metabolic activity, muscle of rat subjected to occlusal alteration, through morphological and histochemical. Will be used 20 male Wistar rats, young adult, weighing on average 200g were divided randomly into two groups: Groups Malocclusion (GM): rats exposed to unilateral extraction (n = 10) and Group No Malocclusion (GSM): mice without extraction ( n = 10). In each group there will be the following subgroups, with n = 5 in each: I - acute stress; II - without stress. The unilateral extraction of molars left will be performed under intraperitoneal anesthesia with 4% Xylazine (10mg/kg) and 10% ketamine (80mg/kg). In both groups: GM and GSM, the rats of subgroup I will be subjected to the protocols of acute stress on the 23rd day after the extraction. During the experimental period the animals are weighed and then the masseter will be collected for analysis by the techniques: HE, SDH, NADH, ROS, and the results would be evaluated the influence of acute stress associated with malocclusion on the morphology of the fibers, oxidative metabolism and muscle inflammation. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

IYOMASA, MAMIE MIZUSAKI; FERNANDES, FERNANDA SILVA; IYOMASA, DANIELA MIZUSAKI; LARA PEREIRA, YAMBA CARLA; RESTREPO FERNANDEZ, RODRIGO ALBERTO; CALZZANI, RICARDO ALEXANDRE; NASCIMENTO, GLAUCE CRIVELARO; ANDRADE LEITE-PANISSI, CHRISTIE RAMOS; MARDEGAN ISSA, JOAO PAULO. Metabolic Changes in Masseter Muscle of Rats Submitted to Acute Stress Associated with Exodontia. PLoS One, v. 10, n. 6, JUN 8 2015. (11/00856-7, 11/15209-7, 11/18889-9)