Morphological and biochemical changes in the pineal gland in pregnancy

Lew, G.M.

doi:10.1016/0024-3205(87)90272-4

Cited by 12 publications

(7 citation statements)

References 25 publications

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“…The physiological cause of the increased melatonin levels in maternal blood during pregnancy remains unknown. An increased activity of melatonin‐synthesizing enzymes in the pineal gland during pregnancy has been suggested as accounting for this rise [51]. Other authors, however, have shown no effect of pregnancy on the pineal gland physiology [21].…”

Section: Discussionmentioning

confidence: 99%

Placental melatonin production and melatonin receptor expression are altered in preeclampsia: new insights into the role of this hormone in pregnancy

Lanoix

Guérin

Vaillancourt

2012

Journal of Pineal Research

130

101

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The melatonin system in preeclamptic pregnancies has been largely overlooked, especially in the placenta. We have previously documented melatonin production and expression of its receptors in normal human placentas. In addition, we and others have shown a beneficial role of melatonin in placental and fetal functions. In line with this, decreased maternal blood levels of melatonin are found in preeclamptic compared with normotensive pregnancies. However, melatonin production and expression of its receptors in preeclamptic compared with normotensive pregnancy placentas has never been examined. This study compares (i) melatonin-synthesizing enzyme expression and activity, (ii) melatonin and serotonin, melatonin's immediate precursor, levels and (iii) expression of MT1 and MT2 melatonin receptors in placentas from preeclamptic and normotensive pregnancies. Protein and mRNA expression of aralkylamine N-acetyltransferase (AANAT) and hydroxyindole O-methyltransferase (HIOMT), the melatonin-synthesizing enzymes, as well as MT1 and MT2 receptors were determined by RT-qPCR and Western blot, respectively. The activities of melatonin-synthesizing enzymes were assessed by radiometric assays while melatonin levels were determined by LC-MS/MS. There is a significant inhibition of AANAT, melatonin's rate-limiting enzyme, expression and activity in preeclamptic placentas, correlating with decreased melatonin levels. Likewise, MT1 and MT2 expression is significantly reduced in preeclamptic compared with normotensive pregnancy placentas. We propose that reduced maternal plasma melatonin levels may be an early diagnostic tool to identify pregnancies complicated by preeclampsia. This study indicates a clinical utility of melatonin as a potential treatment for preeclampsia in women where reduced maternal plasma levels have been identified.

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Section: Discussionmentioning

confidence: 99%

Placental melatonin production and melatonin receptor expression are altered in preeclampsia: new insights into the role of this hormone in pregnancy

Lanoix

Guérin

Vaillancourt

2012

Journal of Pineal Research

130

101

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“…The source of increased melatonin levels in maternal blood during pregnancy is still unknown. It has been reported that those differences could be explained by morphological and biochemical modifications of female pineal gland during pregnancy [36]. However, others did not observe those modifications and have suggested an increased extrapineal melatonin synthesis arising from the placenta [35].…”

Section: Introductionmentioning

confidence: 99%

Human placental trophoblasts synthesize melatonin and express its receptors

Lanoix

Beghdadi

Lafond

et al. 2008

Journal of Pineal Research

152

134

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Although the role of melatonin on fetal development has been the subject of a number of studies, little is known about the function of melatonin in the placenta. We previously showed that melatonin receptors are expressed and are functional in JEG-3 and BeWo cell lines, both in vitro models of human trophoblast. Local synthesis of melatonin in placenta has been proposed, but the human placenta's ability to synthesize melatonin de novo has never been studied. The purpose of this study was to investigate the expression [reverse transcription-polymerase chain reaction (RT-PCR) and western blot analysis] and activity (radiometric assay) of melatonin synthesizing enzymes, and characterize the expression of the melatoninergic receptors in human term villous trophoblast. The results show that arylalkylamine N-acetyltransferase and hydroxyindole O-methyltransferase melatonin synthesizing enzymes are expressed and active in villous trophoblast as well as in JEG-3 and BeWo placental choriocarcinoma cells. In addition, immunohistochemical analysis demonstrated the presence of MT1, MT2, and retinoid-related orphan nuclear receptor alpha melatonin receptor proteins in both villous cytotrophoblast and syncytiotrophoblast (STB) as well as in endothelial cells surrounding the fetal capillaries and in the villous mesenchymal core. RT-PCR and western blot analysis in primary cultures of human term trophoblast confirmed the expression of all three melatonin receptors in villous cytotrophoblast and STB cells. This study demonstrates for the first time a local synthesis of melatonin and expression of its receptors in human trophoblasts and strongly suggests a paracrine, autocrine, and/or intracrine role for this indolamine in placental function and development as well as in protection from oxidative stress.

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“…As a very important neuroendocrine organ, pineal gland can influence many physiological activities, such as circadian rhythm, aging and sexual maturation (Hasegawa et al, 1987; Korf, 1994; Lew, 1987; Pevet, 1988; Reyes, 1982). This gland can be involved by several kinds of lesions, in particular tumors and cysts (Cho et al, 1998; Edwards et al, 1988; Yamamoto, 2001).…”

Section: Introductionmentioning

confidence: 99%

The pineal volume: a three‐dimensional volumetric study in healthy young adults using 3.0 T MR data

Sun

Wang

Tang

et al. 2009

Intl J of Devlp Neuroscience

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It is usually difficult to distinguish small pineal tumors via routine or enhanced magnetic resonance (MR) scan. The knowledge of normal pineal size is helpful to detect small pineal lesions, while very few true volumetric data of pineal glands have been reported. Therefore, we obtained the accurate reference range of normal pineal volumes in 112 individuals aged 20-30 years recruited randomly from a healthy community sample. Transverse and sagittal 3.0T magnetic resonance data were obtained using three-dimensional (3D) T1-weighted FSPGR and T2-weighted SE sequences. True pineal volumes were measured from T1-weighted images, while estimated volumes were calculated using pineal length, width and height. All the glands were divided into three types according to the maximum inner diameter of pineal cysts. The prevalence of asymptomatic pineal cyst is 25.00%, with a slight female predominance. In the whole sample, we found no gender differences of pineal volume, but a significant gender difference of pineal volume index. A significant correlation between pineal volume and asymptomatic cyst was found. After excluding cases with big pineal cysts, there were significant correlations between pineal volume and head circumference, body height and body weight, respectively. This study suggests that asymptomatic pineal cysts may exert an important influence on pineal volume.

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Morphological and biochemical changes in the pineal gland in pregnancy

Cited by 12 publications

References 25 publications

Placental melatonin production and melatonin receptor expression are altered in preeclampsia: new insights into the role of this hormone in pregnancy

Placental melatonin production and melatonin receptor expression are altered in preeclampsia: new insights into the role of this hormone in pregnancy

Human placental trophoblasts synthesize melatonin and express its receptors

The pineal volume: a three‐dimensional volumetric study in healthy young adults using 3.0 T MR data

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