Generalized hyperalgesia in women with endometriosis and its resolution following a successful surgery

Slit2 overexpression results in increased microvessel density and lesion size in mice with induced endometriosis

We recently reported that Slit/Roundabout (ROBO) 1 pathway may be a constituent biomarker for recurrence of endometriosis, likely through promoting angiogenesis. In this study, we sought to determine as whether Slit2 overexpression can facilitate angiogenesis, increase lesion size, and induce hyperalgesia in mice with induced endometriosis. We used 30 Slit2 transgenic (S) and 29 wild-type (W) mice and cross-transplanted endometrial fragments from S to W (group SW) and vice versa (group WS), and also within the S and W (groups SS and WW, respectively), into the peritoneal cavity, inducing endometriosis. We also performed a sham surgery within both S and W mice (groups Sm and Wm, respectively). The size of the ectopic implants, microvessel density (MVD) and immunoreactivity to ROBO1, and vascular endothelial cell growth factor (VEGF) in ectopic and eutopic endometrium, along with hotplate and tail-flick tests in all mice, were then evaluated. We found that the induction of endometriosis resulted in generalized hyperalgesia, which was unaffected by Slit2 overexpression. Slit2 overexpression did increase the lesion size significantly and correlated positively with the MVD in ectopic and eutopic endometrium. Slit2 expression levels appear to correlate with the MVD, but not with VEGF immunoreactivity, in ectopic endometrium. Consequently, we conclude that Slit2 may play an important role in angiogenesis in endometriosis. The increased angiogenesis, as measured by MVD, but not VEGF immunoreactivity, likely resulted in increased lesion size in induced endometriosis. Thus, SLIT2/ROBO1 pathway may be a potential therapeutic target for treating endometriosis.

Providing holistic care for women with chronic pelvic pain

Chronic pelvic pain (CPP) is one of the most common pain conditions affecting women and can have a significant impact on quality of life. Assessment of women with CPP is best approached in a comprehensive, systematic manner that includes exploration of physiological and psychological causes. A range of treatment options that draw from conventional medicine and complementary and alternative modalities should be offered. The women's health nurse plays a pivotal role in all aspects of care.

Visual pain mapping in endometriosis

PURPOSE

To construct pain maps in order to describe the distribution of pelvic pain in a group of endometriosis patients and endometriosis-free patients, to assess the feasibility of this method.

METHODS

A total of 159 patients with pelvic pain who were scheduled for diagnostic laparoscopy.

RESULTS

A total of 117 patients with and 42 patients without endometriosis were included. The pain distribution between these two patient groups appeared to differ in some peripheral anatomical structures. In the endometriosis patients, the pain was most frequently located in the rectouterine pouch.

CONCLUSIONS

In endometriosis patients, pain mapping to assess preoperative pain sensations relative to the anatomic location of endometriotic lesions is feasible. The pain provoked by vaginal examination is frequently perceived as median relative to the actual anatomic location of the endometriotic lesions. Several anatomic and neurophysiological factors may explain this phenomenon.

Therapeutic potential of andrographolide for treating endometriosis

BACKGROUND

Mounting evidence shows that nuclear factor-κB (NF-κB) plays an important role in endometriosis. We therefore evaluated the therapeutic potential of andrographolide, an NF-κB inhibitor.

METHODS

Primary cell cultures were performed using ectopic endometrial tissue specimens and their homologous eutopic endometrial specimens from 16 women with endometriosis, as well as control samples from 4 women without endometriosis. Andrographolide was evaluated for an effect on cell proliferation and cell cycle, DNA-binding activity of NF-κB and expression of cyclooxygenase-2 (COX-2) and tissue factor (TF). In a rat model of endometriosis, andrographolide treatment was evaluated for an effect on lesion size, hotplate response latency and expression of phosphorylated p50 and p65, COX-2 and nerve growth factor (NGF) in ectopic endometrium.

RESULTS

Andrographolide dose dependently suppressed proliferation and cell cycle progression, attenuated DNA-binding activity of NF-κB in endometriotic stromal cells and inhibited COX-2 and TF expression. In the rat experiment, induced endometriosis resulted in reduced response latency. Andrographolide treatment significantly reduced lesion size in a dose-dependent manner and significantly increased response latency. Andrographolide treatment also significantly reduced immunoreactivity of COX-2, phosphorylated p50 and p65, and NGF in ectopic endometrium.

CONCLUSIONS

Treatment with andrographolide significantly suppresses the growth of ectopic endometrium in vitro and in vivo, and results in a significant improvement in generalized hyperalgesia in rats with induced endometriosis. Therefore, andrographolide may be cytoreductive and may relieve pain symptoms in women with endometriosis. With excellent safety and cost profiles, andrographolide could be a promising therapeutic agent for endometriosis.

Valproic acid and progestin inhibit lesion growth and reduce hyperalgesia in experimentally induced endometriosis in rats

Accumulating evidence suggests that endometriosis is an epigenetic disease. This study was designed to evaluate the effect of valproic acid (VPA) and progesterone (P4) in a rat model of endometriosis on serum tumor necrosis factor-α (TNF-α) levels, hot plate and tail-flick latencies, lesion size, and body weight. We used 77 adult female rats, and endometriosis was induced by autotransplanting pieces of uterus (ENDO) or fat (SHAM) to the pelvic cavity. The BLANK group received no surgery. After 2 weeks, the ENDO group was further divided, randomly, into 5 groups, receiving, respectively, treatment with low- and high-dose VPA, P4 alone, VPA + P4, and no treatment. The SHAM rats received no treatment. The BLANK rats were further divided into 2 groups, one received VPA treatment and the other, no treatment. After 4 weeks, all rats were sacrificed. Response latency in hot plate and tail-flick tests, body weight, and serum TNF-α levels were measured before the surgery, before and after the treatment, along with lesion size. We found that induced endometriosis reduced response latency. ENDO rats receiving VPA and/or P4 treatment had significantly reduced lesion size as compared with untreated ones, and had significantly improved response to noxious thermal stimuli. They also had significantly increased weight gain. Serum TNF-α levels increased following surgery but eventually decreased regardless of treatment or not. In conclusion, VPA is well tolerated. Treatment with VPA significantly reduces lesion growth and improves sensitivity to nocifensive stimuli. The improvement is specific to endometriosis-induced hyperalgesia. Thus, histone deacetylase inhibitors may be a promising therapeutics for treating endometriosis.

The prevalence of fibromyalgia in other chronic pain conditions

Central sensitivity syndromes (CSS) include fibromyalgia syndrome (FMS), irritable bowel syndrome, temporomandibular disorder, restless legs syndrome, chronic fatigue syndrome, and other similar chronic painful conditions that are based on central sensitization (CS). CSS are mutually associated. In this paper, prevalence of FMS among other members of CSS has been described. An important recent recognition is an increased prevalence of FMS in other chronic pain conditions with structural pathology, for example, rheumatoid arthritis, systemic lupus, ankylosing spondylitis, osteoarthritis, diabetes mellitus, and inflammatory bowel disease. Diagnosis and proper management of FMS among these diseases are of crucial importance so that unwarranted use of such medications as corticosteroids can be avoided, since FMS often occurs when RA or SLE is relatively mild.

Pelvic pain in women: clinical and scientific aspects

PURPOSE OF REVIEW

Pelvic pain is a common complaint of women that is frequently poorly managed. This review considers the current understanding of the mechanisms of pain perception and the development of chronic pain in the context of three gynaecological pain conditions. Recent advances in the management of these conditions are then discussed.

RECENT FINDINGS

Persistent pelvic pain is associated with central changes, reflected by alterations in psychology, brain structure and function, and dysfunction of the hypothalamic-pituitary-adrenal axis. The many similarities among the conditions support the notion that chronic pain should be treated as a symptom in its own right, however, obtaining a diagnosis remains important to patients. Few new treatments have been developed recently, however, older treatments are being subjected to more rigorous testing and improvements in phenotyping should lead to better design of clinical trials.

SUMMARY

Good quality, well designed clinical trials are urgently required to improve the treatment of pelvic pain in women. However, a variety of successful treatments exist and outcomes can be optimized by individualizing treatment strategies in the context of a multidisciplinary package.