Morfología y Fisiopatología del Fibrocartílago de la ATM. Revisión sistemática / Morphology and Pathophysiology of the TMJ Fibrocartilage. Systemic review

RESUMEN: El objetivo: del presente estudio fue efectuar una revisión actualizada de la morfología, fisiopatología y aspectos moleculares de la capa fibrocartilaginosa de las ATM en humanos. Método: se realizó búsqueda electrónica y manual con los términos MeSH "TMJ" y "fibrocartilage", sin límite de fecha o idioma. Los desenlaces definidos fueron: morfología del fibrocartílago, fisiopatología del fibrocartílago articular, modeladores moleculares del fibrocartílago y deterioro del fibrocartílago. Resultados: Se identificaron 1.071 títulos de artículos que después de las exclusiones, fueron seleccionados 16 a texto completo para la revisión. El fibrocartílago (FC) que cubre las superficies de las ATM es un tejido crítico en el establecimiento y la tasa de progresión de las alteraciones óseas degenerativas, clínicamente sus discontinuidades se asocian a patologías que provocan dolor, ruidos y limitación funcional. Conclusiones: A pesar de la diversidad metodológica, heterogeneidad de objetivos y diferentes características de los estudios incluidos en la revisión, el fibrocartílago de la ATM, como tejido avascular, determina fisiología de baja capacidad reparativa y mayor frecuencia de patología del FC en mujeres en edad fértil, asociado a receptores hormonales. La fisiopatología muestra reacciones inmunitarias que incrementan la acción de MMPs, interleucinas y FNTα, responsables de la degradación de la matriz extracelular, destrucción celular y morfológica del fibrocartílago, que conducen a sintomatología inflamatoria y degenerativa de pacientes que presentan artralgias y sinovitis en las ATM.

ABSTRACT: The aim: of the present study was to carry out an updated review of the morphology, physiopathology and molecular aspects of the TMJ fibrocartilage in humans. Method: electronic/manual search was performed with the MeSH terms "TMJ" and "fibrocartilage", with no date or language limit. The defined outcomes were: morphology of the fibrocartilage, physiopathology of the articular fibrocartilage, fibrocartilage molecular modelers and fibrocartilage deterioration. Results: 1071 articles were identified and after exclusions, 16 full-texts were selected for review. The fibrocartilage (FC) that covers the surfaces of the TMJ is a critical tissue in the establishment and progression rate of degenerative bone diseases; clinically, its discontinuities are associated with pain, noise and functional limitation. Conclusions: In spite of the methodological diversity, heterogeneity of objectives and different characteristics of the patients included in the review, TMJ fibrocartilage, as avascular tissue, determines a physiology of low reparative capacity, observed with greater frequency of FC damage in women of fertile age, associated with a greater amount of hormonal receptors. The physiopathology shows that the immune reactions increase some MMPs, interleukins and FNTα, which are linked to the degradation of the extracellular matrix, FC cellular and morphological destruction and define the inflammatory and degenerative symptomatology of patients who present TMJ arthralgia´s and synovitis.

Modulation of spermatozoon acrosome reaction

Spermatozoon acrosome reaction is an exocytotic event of the utmost importance for the development of mammalian fertilisation. Current evidence shows that the triggering of the acrosome reaction (AR) could be regulated by the action of diverse compounds, namely, metabolites, neurotransmitters and hormones. The aim of the present review is to describe the modulating effects of several compounds that have been classified as inductors or inhibitors of acrosome reaction. Among AR inductors, it is necessary to mention progesterone, angiotensin II, atrial natriuretic peptide, cathecolamines, insulin, leptin, relaxin and other hormones. Regarding the inhibitors, oestradiol and epidermal growth factor are among the substances that retard AR. It is worth mentioning that gamma-aminobutyric acid, a neurotransmitter known to be an inhibitor in the central nervous system, has been shown to induce AR. The multiple hormones located in the fluids of the female reproductive tract are also likely to act as subtle regulators of AR, constituting a fundamental aspect for the development of successful fertilisation. Finally, it is necessary to emphasise that the study of regulation exerted by hormones and other compounds on AR is essential for further understanding of mammalian reproductive biology, especially spermatozoon physiology.