Role of nerve fibres in endometriosis

Abstract

Endometriosis is an oestrogen-dependent inflammatory disease. Endometriosis is often associated with pain symptoms such as dysmenorrhoea, dyspareunia, dyschezia, dysuria and low back pain. Although increased immune cells in peritoneal fluid, adhesions, retrograde menstruation and prostaglandins are considered to be causes of pain symptoms in endometriosis, the underlying mechanisms by which pain is generated still remain unknown. Recently numerous studies have focused on nerve fibres and neurotrophins in eutopic endometrium and endometriotic lesions from women with endometriosis as well as in animal models as a source of pain generation. Nerve fibres in eutopic and ectopic endometrium may be activated and/or sensitised by many inflammatory mediators to cause pain and tenderness. Neurotrophins are known to regulate the survival, development and function of nerve fibres. However, many other molecules may act as a neurotrophic factor in endometriosis. Increased numbers of nerve fibres, increased amount of neurotrophins and different types of nerve fibres in endometriosis may explain why women with endometriosis experience pain.