Sex-related differences in response to masseteric injections of glutamate and nerve growth factor in healthy human participants

• Published in: Scientific reports 2021-07, Vol.11 (1), p.13873-13873, Article 13873
• Main Authors: Alhilou, Abdelrahman M., Shimada, Akiko, Svensson, Camilla I., Svensson, Peter, Ernberg, Malin, Cairns, Brian E., Christidis, Nikolaos
• Format: Article
• Language: English
• Subjects: 631/378; 692/53; 692/698; Adult; Biomarkers - metabolism; Connective Tissue - metabolism; Female; Gender differences; Glutamic Acid - pharmacology; Glutamic acid receptors (ionotropic); Healthy Volunteers; Humanities and Social Sciences; Humans; Injection; Injections; Male; Masseter muscle; Masseter Muscle - drug effects; Mastication; multidisciplinary; Muscle Cells - drug effects; Muscle Cells - metabolism; N-Methyl-D-aspartic acid receptors; Nerve Fibers - drug effects; Nerve Fibers - metabolism; Nerve growth factor; Nerve Growth Factor - pharmacology; Nociceptors; Pain; Pain - pathology; Pain perception; Pain Threshold - drug effects; Pressure; Receptors, N-Methyl-D-Aspartate - metabolism; Science; Science (multidisciplinary); Sex Characteristics; Sex differences; Substance P; Substance P - metabolism; Time Factors
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-021-93171-2

The neurophysiological mechanisms underlying NGF-induced masseter muscle sensitization and sex-related differences in its effect are not well understood in humans. Therefore, this longitudinal cohort study aimed to investigate the effect of NGF injection on the density and expression of substance P, NMDA-receptors and NGF by the nerve fibers in the human masseter muscle, to correlate expression with pain characteristics, and to determine any possible sex-related differences in these effects of NGF. The magnitude of NGF-induced mechanical sensitization and pain during oral function was significantly greater in women than in men (P