Melatonin plays a critical role in a variety of mammalian reproductive processes not only acting on the central nervous system but also behaving as a peripheral physiologic regulator. To address the relevance of melatonin to the maintenance of pregnancy at the feto-maternal interface, we investigated the expression of two types of membrane melatonin receptors, MT1 and MT2, as well as arylalkylamine N-acetyltransferase (AA-NAT) and hydroxyindole-O-methyltransferase (HIOMT), the two enzymes required for the conversion of serotonin to melatonin, in the human placenta and the effect of melatonin on the release of human chorionic gonadotropin (hCG) from cultured human trophoblast cells. RT-PCR analysis and DNA sequencing revealed that transcripts of MT1, MT2, AA-NAT, and HIOMT were present in the first-trimester human placenta. We also found that melatonin significantly potentiated hCG secretion at optimal concentrations. These results suggest that melatonin may regulate human placental function in a paracrine/autocrine manner, providing evidence for a novel role in human reproduction.
The pineal hormone melatonin is thought to mediate the effects of the pineal gland on seasonal reproduction by altering the release of gonadotropins. The mechanism by which melatonin controls gonadotropin secretion has been ob- This concentration of melatonin also significantly reduced the release of LH into the medium. The increased release of LIIRH induced by melatonin (10 FM) was completely blocked by the addition of LH (50 ng/ml), which by itself had no sigicant effect on LHRH release. Rat LH antiserum (final dilution, 1:1800) significantly elevated LHRH output, whereas normal rabbit serum at a similar dilution had no effect. Finally, LHRH Melatonin, the pineal hormone, responds to seasonal changes in photoperiod to influence reproductive rhythms in seasonal breeders; however, the mechanism by which melatonin brings about its diverse effects is unknown (1). The development of a high-affinity high-specific-activity ligand, 2-[1251]iodomelatonin, has allowed the identification of melatonin-binding sites within the brain. The highest concentration of melatonin receptors occurs in the pars tuberalis of mammals (2-4), and it may be that this part of the vertebrate pituitary gland is not the nonfunctional lobe it was thought to be. The cells of this structure have many of the ultrastructural characteristics considered necessary for endocrine secretion (5). Furthermore, seasonal fluctuations in its cytological features, seemingly in concert with reproductive cycles, may represent the morphological expression of seasonal changes in its endocrine function (6). Luteinizing hormone (LH)-containing cells in the pars tuberalis of rats were first demonstrated through immunocytochemistry by Baker et al. (7), and it is noteworthy that the distribution of these cells corresponds to the distribution of terminals of the LH-releasing hormone (LHRH) neurons in the overlying median eminence. When the median eminencepars tuberalis was incubated in vitro in the presence of medium with a high potassium concentration, there was release of LH into the medium; LH release could also be stimulated by addition of LHRH (8). Although there is some evidence of LH in hypothalamic neurons, it appears that the largest amount of LH in the median eminence-pars tuberalis complex actually occurs in the gonadotrope-like cells in the pars tuberalis (21).The concept of short-loop feedback by which pituitary hormones inhibit their own release (9-11) is well established. The short-loop feedback of LH has been thought to be mediated either by LH neurons within the hypothalamus (11) or by retrograde flow of blood in the hypophyseal portal vessels that transport high concentrations of LH to the median eminence (12). We do not believe that either of these is the major mechanism for the LH negative short-loop feedback. Rather, we hypothesize that LH is released from the gonadotropes of the pars tuberalis and diffuses into the median eminence where it suppresses the release of LHRH from the terminals of the LHRH neurons either by a direct action or by...
Although it is difficult in Western medicine to eliminate edema occurring in the lower extremities after intrapelvic lymph node dissection for malignant gynecologic tumors, we successfully treated or prevented this postoperative complication with moxibustion and acupuncture, initiated after the occurrence of lymphedema in 12 patients and as soon as possible after surgery in 12 others. An increase in deep body temperature with acupuncture or moxibustion was found to be essential for successful treatment.
Endometrial cancer is believed to have a better prognosis than cervical cancer. However, this is not necessarily true for cases beyond International Federation of Gynecology and Obstetrics (FIGO) stage III, and advanced endometrial cancer with distant metastases in particular has a poor prognosis. Moreover, there is no established therapy for advanced endometrial cancer. Recently, we treated two patients with endometrial cancer with multiple lung metastases (FIGO stage IVb). Both patients had massive uncontrollable genital bleeding and eventually progressed to anemia. The imminent severe bleeding was considered to be a major reason for exacerbation of their general condition. Therefore, hysterectomy was performed as a counter-measure to improve their general condition. In their postoperative course, the two patients successfully underwent T-J chemotherapy [paclitaxel: 210 m/m2 over 3h; carboplatin: area under the curve (AUC) 5]. Six courses of the regimen were given every 3-4 weeks. Multiple lung shadows in chest X-P and computed tomography (CT) were reduced in number and size after two courses of T-J chemotherapy. The multiple lung metastases either disappeared or just remained as scars after six courses. There has been no evidence of recurrence for 28 months in one patient and 7 months in the other patient.
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