Changes in TRPV1 expression in the POA of ovariectomized rats regulated by NE-dependent α2-ADR may be involved in hot flashes.

BACKGROUND: Hot flashes (HF) caused by low estrogen in menopause result from changes in thermoregulatory processes in the hypothalamic preoptic area (POA). In the POA, transient receptor potential vanilloid 1 (TRPV1) participates in heat dissipation processes. Studies suggest that TRPV1 expression may be regulated by norepinephrine (NE)-activated α2-adrenergic receptors (α2-ADR) in the dorsal root ganglia. The goal of this study was to investigate the relationship between NE-regulated TRPV1 expression in the POA of ovariectomized rats and the development of HF. METHODS: Ninety female adult Sprague-Dawley rats were divided into three groups: SHAM, OVX and E2 (n = 30 per group). The numbers of TRPV1- and α2-ADR-positive cells and the expression of TRPV1 and α2-ADR in the POA of each group were determined using immunohistochemical staining after 4 weeks of estrogen treatment. Western blotting was used to detect the expression of TRPV1 and α2-ADR in the POA tissue, and NE content in the POA tissue was detected using high-performance liquid chromatography. In addition, the coexpression of TRPV1 and α2-ADR in POA neurons was investigated using immunofluorescent staining. RESULTS: In the POA of ovariectomized rats, the number of TRPV1-positive cells and TRPV1 expression increased while NE content decreased. Concomitantly, the number of α2-ADR-positive cells and α2-ADR expression decreased. Estrogen treatment reversed these changes in the POA of ovariectomized rats. In addition, we found that TRPV1 and α2-ADR were coexpressed in POA neurons. CONCLUSIONS: Under low-estrogen conditions, NE-activated α2-ADR regulated TRPV1 expression in the POA, and increased expression of TRPV1 may be an important factor for triggering HF.

[Clinical study of gasless abdominal-wall lifting laparoscopic myomectomy with 5 mm laparoscope].

OBJECTIVE: To explore the feasibility, advantages and clinical value of gasless abdominal-wall lifting laparoscopic myomectomy with 5 mm laparoscope and 2 abdominal holes (1.5-hole-gasless-laparoscopic myomectomy). METHODS: A total of 90 cases of uterine fibroids were randomly divided into 2 groups. Lifting gasless group (n = 46) underwent gasless abdominal-wall lifting laparoscopic myomectomy with 5 mm laparoscope and 2 abdominal holes, and pneumoperitoneum group (n = 44) pneumoperitoneum laparoscopic myomectomy. The operative duration, blood loss volume, average time of single-myoma-removal, intestinal function recovery and hospital stay of both groups were compared. RESULTS: The operative duration, blood loss volume and average time of single-myoma-removal of lifting gasless group were respectively significantly less than those of pneumoperitoneum group (P < 0.01) . The postoperative intestinal function recovery and postoperative hospital stay had no significant difference between two groups (P > 0.05). Three cases of pneumoperitoneum group were converted successfully into myomectomy with traditional 3-hole gasless abdominal wall lifting laparoscopy because of large fibroids in uterine isthmus. A total of 12 newly discovered myomas, not pre-detected ultrasonically, were removed in 10 cases of lifting gasless group. CONCLUSION: 1.5-hole-gasless-laparoscopic myomectomy, like traditional gasless laparoscopy, may avoid the complications of laparoscopic CO2 pneumoperitoneum. The smaller laparoscope-hole and sole operating hole make this maneuver a safe, easy and mini-invasive procedure. It is more suitable for clinical application and popularity in primary care.