Abstract：
:The purpose of this study was to determine and compare the effects of chronic melatonin treatment in vivo on several aspects of prolactin (PRL) cell activity (PRL synthesis, storage, and release) in vitro in male and female Syrian hamsters. Adult male and female hamsters were maintained on long photoperiod and treated with daily late afternoon injections of melatonin (25 micrograms) or vehicle for 11 weeks. Melatonin treatment resulted in an 85% and 65% decrease in serum PRL levels in male and female hamsters, respectively. There was a similar 79% and 64% decrease in PRL release in vitro from pituitaries of male and female hamsters respectively, treated with melatonin in vivo. Total stored PRL was 75% lower in male hamsters and 62% lower in female hamsters receiving melatonin. The synthesis of PRL by pituitaries from melatonin-treated male hamsters was reduced by 65%, whereas in melatonin-treated females it was decreased by 58%. Both nanomolar and micromolar doses of melatonin in vitro caused a modest but significant decrease (14-19%) in the amount of PRL stored in and released from normal male pituitaries without affecting synthesis. The inhibitory effects of melatonin on PRL cell function appear to be more pronounced in male than in female hamsters suggesting a sexually dimorphic response to this pineal hormone. While melatonin's PRL-inhibitory effects appear to be exerted primarily via indirect neuroendocrine mechanisms, a secondary component of its overall regulation of PRL processing may involve direct pituitary mechanisms as well.
journal_name
J Pineal Resjournal_title
Journal of pineal researchauthors
Blask DEdoi
10.1111/j.1600-079x.1989.tb00446.xsubject
Has Abstractpub_date
1989-01-01 00:00:00pages
221-30issue
3eissn
0742-3098issn
1600-079Xjournal_volume
7pub_type
杂志文章abstract：:Djungarian hamsters kept in long photoperiod (16:8 L:D) were injected daily at 0800, 1200, or 1600 with 25 micrograms of melatonin. During 90 days of treatment, body weight and fur coloration were checked at weekly intervals, and at the end of the treatment the reproductive status of the hamsters and their thermoregul...
journal_title：Journal of pineal research
pub_type： 杂志文章
doi：10.1111/j.1600-079x.1985.tb00719.x
更新日期：1985-01-01 00:00:00
abstract：:Melatonin is a powerful antioxidant and free radical scavenger. A large body of in vivo and in vitro evidence shows that melatonin effectively inhibits membrane lipid peroxidation; this damage was based on the measurement of malondialdehyde and/or 4-hydroxynonenal levels. In the current study, for the first time using...
journal_title：Journal of pineal research
pub_type： 杂志文章
doi：10.1111/j.1600-079X.2005.00311.x
更新日期：2006-05-01 00:00:00
abstract：:The circadian clock plays a vital role in physiology and behavior such as the sleep-wake cycle and blood pressure and hormone levels. Immune responses also display circadian rhythmicity and particularly pineal melatonin contributes to immunological processes. Little attention, however, is given to mechanisms underlyin...
journal_title：Journal of pineal research
pub_type： 杂志文章
doi：10.1111/jpi.12230
更新日期：2015-05-01 00:00:00
abstract：:The effects of noradrenergic and cholinergic receptor agonists on intracellular Ca2+ concentration ([Ca2+]i) in single dissociated rat pineal cells were investigated by microfluorimetric measurements in Fura-2 acetoxymethyl ester (Fura-2/AM) loaded cells. Noradrenaline (NA) evoked characteristic biphasic increments of...
journal_title：Journal of pineal research
pub_type： 杂志文章
doi：10.1111/j.1600-079x.1996.tb00266.x
更新日期：1996-08-01 00:00:00
abstract：:A physiologically based model of arousal dynamics is improved to incorporate the effects of the light spectrum on circadian phase resetting, melatonin suppression, and subjective sleepiness. To account for these nonvisual effects of light, melanopic irradiance replaces photopic illuminance that was used previously in ...
journal_title：Journal of pineal research
pub_type： 杂志文章
doi：10.1111/jpi.12681
更新日期：2020-10-01 00:00:00
abstract：:The binding characteristics of the tritiated pineal hormone, [3H] melatonin, were studied in brain tissues using in vitro binding techniques. In synaptosomal membranes prepared from rat hippocampus and subjected to preincubation at 37 degrees C and multiple washings, high-affinity binding of [3H] melatonin significant...
journal_title：Journal of pineal research
pub_type： 杂志文章
doi：10.1111/j.1600-079x.1987.tb00844.x
更新日期：1987-01-01 00:00:00
abstract：:In three separate experiments, the effect of acute exposure to either artificial or natural light during darkness of pineal N-acetyltransferase (NAT) activity and melatonin content was studied in the cotton rat (Sigmodon hispidus). The exposure of animals to an artificial-light irradiance of 160,000 microW/cm2 during ...
journal_title：Journal of pineal research
pub_type： 杂志文章
doi：10.1111/j.1600-079x.1985.tb00717.x
更新日期：1985-01-01 00:00:00
abstract：:Despite state-of-the-art pharmaceutical regimens, continuous improvements in diagnostic techniques as well as refinements in equipment and interventional procedures, many diseases remain refractory to conventional therapies. Recent advances in stem cell (SC) biology have opened an avenue to exploring its therapeutic p...
journal_title：Journal of pineal research
pub_type： 杂志文章,评审
doi：10.1111/jpi.12372
更新日期：2017-03-01 00:00:00
abstract：:Melatonin, the main secretary product of the pineal gland, is potentially effective in the prevention of a number of diseases in which free radical processes are involved. The development of hypercholesterolemia is a multifactorial process in which elevated oxidized low-density lipoprotein (ox-LDL) levels play a centr...
journal_title：Journal of pineal research
pub_type： 杂志文章
doi：10.1111/j.1600-079X.2008.00595.x
更新日期：2008-10-01 00:00:00
abstract：:Hepatocellular carcinoma (HCC) is one of the most common cancers and its incidence is increasing worldwide. Melatonin, an indoleamine hormone, exerts anti-oxidant, immunomodulatory, anti-aging, and antitumor effects. Previous studies have shown that melatonin can act through specific receptors, including MT(1), MT(2),...
journal_title：Journal of pineal research
pub_type： 杂志文章
doi：10.1111/j.1600-079X.2009.00719.x
更新日期：2009-11-01 00:00:00
abstract：:5-Methoxycarbonylamino-N-acetyltryptamine (MCA-NAT) has been initially described as a ligand at non MT(1), non MT(2) melatonin binding site (MT3) selective versus MT(1) and MT(2), two membrane melatonin receptors. MCA-NAT activity has been reported by others in different models, in vivo, particularly in the intra-ocul...
journal_title：Journal of pineal research
pub_type： 杂志文章
doi：10.1111/j.1600-079X.2010.00746.x
更新日期：2010-04-01 00:00:00
abstract：:To examine the role of melatonin in pathological hyperprolactinemia we compared untreated young females (N = 5) with hyperprolactinemic amenorrhea owing to pituitary microadenoma to healthy female controls (N = 6). Serum samples for melatonin, prolactin, and luteinizing hormone (LH) concentrations were obtained every ...
journal_title：Journal of pineal research
pub_type： 杂志文章
doi：10.1111/j.1600-079x.1996.tb00242.x
更新日期：1996-03-01 00:00:00
abstract：:Classical anticancer therapies often are ineffective in patients with malignant glioma who have a survival of <1 year. Our previous studies showed a potent inhibitory effect of melatonin on glioma cell proliferation. This effect seems to be mediated by the well-known antioxidant properties of this molecule and the neg...
journal_title：Journal of pineal research
pub_type： 杂志文章
doi：10.1111/j.1600-079X.2007.00468.x
更新日期：2007-10-01 00:00:00
abstract：:The quantitative autoradiographic 2-[14C]deoxyglucose method was employed to map the metabolic activity of the superior cervical ganglion and the entire brain during unilateral electrical stimulation of the cervical sympathetic trunk in the urethane-anesthetized rat. Stimulation of the cervical sympathetic trunk incre...
journal_title：Journal of pineal research
pub_type： 杂志文章
doi：10.1111/j.1600-079x.1988.tb00768.x
更新日期：1988-01-01 00:00:00
abstract：:Melatonin is known to regulate a variety of physiological processes including control of circadian rhythms, regulation of seasonal reproductive function, regulation of body temperature, and so forth. Accumulating evidence from in vitro and in vivo experiments using rodent and chicken has also suggested that melatonin ...
journal_title：Journal of pineal research
pub_type： 杂志文章
doi：10.1111/j.1600-079X.2006.00410.x
更新日期：2007-04-01 00:00:00
abstract：:The aim of this study was to compare the circadian control of melatonin production in teleosts. To do so, the effects of ophthalmectomy on circulating melatonin rhythms were studied along with ex vivo pineal culture in six different teleosts. Results strongly suggested that the circadian control of melatonin productio...
journal_title：Journal of pineal research
pub_type： 杂志文章
doi：10.1111/j.1600-079X.2007.00480.x
更新日期：2007-11-01 00:00:00
abstract：:Cardiac tissue loss is one of the most important factors leading to the unsatisfactory recovery even after treatment of ischemic heart disease. Melatonin, a circadian molecule with marked antioxidant properties, protects against ischemia-reperfusion (IR) injury. In particular, the myocardial protection of melatonin is...
journal_title：Journal of pineal research
pub_type： 杂志文章,评审
doi：10.1111/jpi.12175
更新日期：2014-11-01 00:00:00
abstract：:The objective of this study was to apply the radioimmunoassay for 6-sulphatoxymelatonin (aMT6s) to rat urine, and use it to study the source of aMT6s. The radioimmunoassay was found to have acceptable within- and between-assay variation, excellent specificity, and good parallelism between the standard and unknown. Bec...
journal_title：Journal of pineal research
pub_type： 杂志文章
doi：10.1111/j.1600-079x.1991.tb00831.x
更新日期：1991-04-01 00:00:00
abstract：:Melatonin as a potent antioxidant exhibits important nutritional and medicinal values. To produce melatonin-enriched milk will benefit the consumers. In this study, a sheep bioreactor which generates melatonin-enriched milk has been successfully developed by the technology that combined CRISPR/Cas9 system and microinj...
journal_title：Journal of pineal research
pub_type： 杂志文章
doi：10.1111/jpi.12406
更新日期：2017-08-01 00:00:00
abstract：:Melatonin, a major pineal secretory product, exerts a range of physiological and neuroprotective effects. However, the functional significance of melatonin in determining neural identity, and the mechanisms by which this may occur, is unknown. In this study, P19 cells were used as a model system and cell behavior was ...
journal_title：Journal of pineal research
pub_type： 杂志文章
doi：10.1111/jpi.12153
更新日期：2014-09-01 00:00:00
abstract：:Melatonin is an endogenous indoleamine, produced mainly by the pineal gland. Melatonin has been proven to have chronobiotic, antioxidant, antihypertensive, anxiolytic and sedative properties. There are also experimental and clinical data supporting an analgesic role of melatonin. In experimental studies, melatonin sho...
journal_title：Journal of pineal research
pub_type： 杂志文章,评审
doi：10.1111/j.1600-079X.2011.00895.x
更新日期：2011-10-01 00:00:00
abstract：:N-acetylserotonin methyltransferase (ASMT), the last enzyme in the synthesis of melatonin, catalyzes N-acetylserotonin into melatonin. For the first time, we cloned ASMT from rice through the analysis of recombinant Escherichia coli harboring putative rice O-methyltransferase (OMT) cDNAs. In total, 18 full-length cDNA...
journal_title：Journal of pineal research
pub_type： 杂志文章
doi：10.1111/j.1600-079X.2010.00841.x
更新日期：2011-04-01 00:00:00
abstract：:A role of D2-dopaminergic neurotransmission in the regulation of melatonin biosynthesis in retina was studied in vivo in chickens. The nighttime rise in serotonin N-acetyltransferase (NAT)--the penultimate and key regulatory melatonin-synthesizing enzyme--was potently inhibited by both acute light exposure and agonist...
journal_title：Journal of pineal research
pub_type： 杂志文章
doi：10.1111/j.1600-079x.1991.tb00466.x
更新日期：1991-10-01 00:00:00
abstract：:The objective of this study was to determine the role of alpha-adrenoceptors in melatonin production by rat pineal gland. Pineal glands were isolated from adult male rats and maintained in organ baths. The perfusate was sampled every 5 min, stored, and later assayed for melatonin. Exposure to norepinephrine (10 microM...
journal_title：Journal of pineal research
pub_type： 杂志文章
doi：10.1034/j.1600-079x.2002.01842.x
更新日期：2002-05-01 00:00:00
abstract：:Melatonin possesses a number of important biologic activities including oncostatic, anti-oxidant, and immunostimulatory actions. This study was designed to assess the effects of melatonin on inflammation-related gene expression in lipopolysaccharide (LPS)-stimulated human peripheral blood mononuclear cells (PBMCs), us...
journal_title：Journal of pineal research
pub_type： 杂志文章
doi：10.1111/j.1600-079X.2007.00452.x
更新日期：2007-09-01 00:00:00
abstract：:Urotoxicity is one of the major problems associated with cyclophosphamide (CP) chemotherapy in cancer patients. Melatonin is a potent antioxidant and reduces CP-induced urotoxicity. However, the molecular mechanisms of protection offered by melatonin are not yet clear. The present study investigated the role of nuclea...
journal_title：Journal of pineal research
pub_type： 杂志文章
doi：10.1111/j.1600-079X.2010.00756.x
更新日期：2010-05-01 00:00:00
abstract：:The frequency of mitoses of adrenaline (A) cells and noradrenaline (N) cells in the adrenal medulla of nonoperated (NO), sham-operated (SPX), and pinealectomized (PX) male, 53-day-old Holtzman rats (n = 133) was investigated by means of light microscopy. Animals were killed at eight time points during a standardized 2...
journal_title：Journal of pineal research
pub_type： 杂志文章
doi：10.1111/j.1600-079x.1990.tb00803.x
更新日期：1990-01-01 00:00:00
abstract：:Impaired Ca2+ homeostasis and smooth muscle contractility co-exist in acute cholecystitis (AC) leading to gallbladder dysfunction. There is no pharmacological treatment for this pathological condition. Our aim was to evaluate the effects of melatonin treatment on Ca2+ signaling pathways and contractility altered by ch...
journal_title：Journal of pineal research
pub_type： 杂志文章
doi：10.1111/j.1600-079X.2007.00520.x
更新日期：2008-04-01 00:00:00
abstract：:In the current study, a fundamental question, that is, the mechanisms related to the beneficial effects of melatonin on mammalian embryonic development, was addressed. To examine the potential beneficial effects of melatonin on bovine embryonic development, different concentrations of melatonin (10(-11), 10(-9), 10(-7...
journal_title：Journal of pineal research
pub_type： 杂志文章
doi：10.1111/jpi.12126
更新日期：2014-04-01 00:00:00
abstract：:Previous data have demonstrated that a single 1-hr light pulse at night affects the secretion of melatonin in the ram if it was given at the appropriate time. This paper reports the effect on melatonin secretion of a 1-hr light pulse given at two different times at night to two groups of rams kept in constant darkness...
journal_title：Journal of pineal research
pub_type： 杂志文章
doi：10.1111/j.1600-079x.1996.tb00289.x
更新日期：1996-11-01 00:00:00
