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Effects of different levels of spirulina (Arthrospira platensis) supplementation on productive performance, nutrient digestibility, blood metabolites, and meat quality of growing Najdi lambs. Trop Anim Health Prod 2022; 54:124. [PMID: 35235076 DOI: 10.1007/s11250-022-03115-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 02/18/2022] [Indexed: 10/19/2022]
Abstract
In a 90-day study, 32 growing lambs aged 3 months were utilized to evaluate the effects of various levels of spirulina dietary supplement on productive performance, nutritional digestibility, and meat quality in growing Najdi lambs. The lambs were put into 4 groups of 8 lambs each at random. The diet consisted of a total mixed ration (TMR) without spirulina (CONT), and the TMR diet supplemented with spirulina at the levels of 2 ppm (SPP2), 4 ppm (SPP4), and 8 ppm (SPP8). The treatment groups, especially SPP8, showed a significant (p < 0.05) increase in body weight and average daily gain (p < 0.05) compared to the CONT group. Dry matter intake and acid detergent fiber were also significantly (p ≤ 0.05) higher in SPP8 compared to other treated groups and CONT. The N absorption, N retention, and percentage of N digestibility coefficient were greater (P < 0.05) in lambs in the treatment groups than in the CONT. Blood biochemistry variables were not significantly (p ≤ 0.05) affected by the treatments, with the exception of the serum concentration of triglyceride and bilirubin. Carcass profile and meat quality, including back fat, body wall fat, and cooking loss, were increased significantly (p ≤ 0.05) with dietary spirulina. From the results of the present study, it was concluded that spirulina dietary supplementation at the level of 8 ppm increased weight gain, nutritional digestibility, nitrogen utilization, and meat composition in growing Najdi lambs.
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Kravchenko LB, Muraleva NA. Melatonin and Sexual Maturation in Bank (Clethrionomys glareolus) and Grey-Sided (Clethrionomys rufocanus) Voles in Experimental Conditions. BIOL BULL+ 2022. [DOI: 10.1134/s1062359021140107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Rzepka-Migut B, Paprocka J. Melatonin-Measurement Methods and the Factors Modifying the Results. A Systematic Review of the Literature. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:E1916. [PMID: 32183489 PMCID: PMC7142625 DOI: 10.3390/ijerph17061916] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/09/2020] [Revised: 03/04/2020] [Accepted: 03/06/2020] [Indexed: 01/11/2023]
Abstract
Melatonin plays an important role in regulating the sleep-wake cycle and adaptation to environmental changes. Concentration measurements in bioliquids such as serum/plasma, saliva and urine are widely used to assess peripheral rhythm. The aim of the study was to compare methods and conditions of determinations carried out with the identification of factors potentially affecting the measurements obtained. We have identified a group of modifiable and unmodifiable factors that facilitate data interpretation. Knowledge of modifiers allows you to carefully plan the test protocol and then compare the results. There is no one universal sampling standard, because the choice of method and biofluid depends on the purpose of the study and the research group.
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Affiliation(s)
- Beata Rzepka-Migut
- Department of Pediatric Neurology and Pediatrics, St. Queen Jadwiga’s Regional Clinical Hospital No 2 Rzeszów, 35-301 Rzeszów, Poland;
| | - Justyna Paprocka
- Department of Pediatric Neurology, Faculty of Medical Sciences, Medical University of Silesia, 40-752 Katowice, Poland
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Hanish AE, Butman JA, Thomas F, Yao J, Han JC. Pineal hypoplasia, reduced melatonin and sleep disturbance in patients with PAX6 haploinsufficiency. J Sleep Res 2016; 25:16-22. [PMID: 26439359 PMCID: PMC4823177 DOI: 10.1111/jsr.12345] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Accepted: 08/19/2015] [Indexed: 01/30/2023]
Abstract
In rodent studies, paired box 6 (PAX6) appears to play an important role in the development of the pineal, the primary source of the circadian regulating hormone, melatonin. Pineal hypoplasia has been previously reported in patients with PAX6 haploinsufficiency (+/−); however, pineal measurement, melatonin concentrations and sleep quality have not been reported. This cross-sectional descriptive study examined pineal volume, melatonin secretion and sleep disturbance in 37 patients with PAX6+/− (age 15.3 ± 9.9 years) and 17 healthy controls (16.0 ± 7.2 years), within an inpatient setting at the Clinical Research Center of the National Institutes of Health, Bethesda, Maryland, USA. Pineal volume was evaluated by magnetic resonance imaging. Diurnal serum cortisol, serum melatonin and urine 6-sulphatoxymelatonin concentrations were measured by enzyme-linked immunosorbent assay. The Child Sleep Habits Questionnaire was administered for patients <13 years old. Pineal volume was fivefold lower in PAX6+/− versus controls (mean ± SD: 25 ± 15 versus 129 ± 50 μL, P < 0.001). Midnight serum cortisol was similar in PAX6+/− versus controls (P = 0.14). Midnight serum melatonin was > twofold lower in PAX6+/− versus controls [median (25th-75 th): 28 (22-42) versus 71 (46-88) pg mL-(1), P < 0.001]. First morning void urinary 6-sulphatoxymelatonin was fourfold lower in PAX6+/− versus controls [11 (6-26) versus 45 (34-61) ng mg(-1) Cr, P = 0.001]. Child Sleep Habits Questionnaire score was higher in PAX6+/− versus controls (48 ± 6 versus 41 ± 5, P = 0.03). The current findings suggest that PAX6+/− is associated with smaller pineal size, lower melatonin secretion and greater parental report of sleep disturbances in children. Further studies are needed to explore the potential use of melatonin replacement for improving sleep quality in patients with PAX6+/−.
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Affiliation(s)
- Alyson E. Hanish
- Section on Growth and Obesity, Program in Developmental Endocrinology and Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health (NIH), Bethesda, MD 20892 USA
- National Institute of Nursing Research, NIH, Bethesda, MD 20892 USA
- University of Iowa, College of Nursing, Iowa City, IA 52242 USA
| | - John A. Butman
- Radiology and Imaging Sciences, Clinical Center, NIH, Bethesda, MD 20892 USA
| | - Francine Thomas
- Radiology and Imaging Sciences, Clinical Center, NIH, Bethesda, MD 20892 USA
| | - Jianhua Yao
- Radiology and Imaging Sciences, Clinical Center, NIH, Bethesda, MD 20892 USA
| | - Joan C. Han
- Section on Growth and Obesity, Program in Developmental Endocrinology and Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health (NIH), Bethesda, MD 20892 USA
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Malau-Aduli AEO, Kashani A. Molecular genetics-nutrition interactions in the expression of AANAT, ADRB3, BTG2 and FASN genes in the heart, kidney and liver of Australian lambs supplemented with Spirulina (Arthrospira platensis). Genes Genomics 2015. [DOI: 10.1007/s13258-015-0294-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Kashani A, Holman BWB, Nichols PD, Malau-Aduli AEO. Effect of dietary supplementation with Spirulina on the expressions of AANAT, ADRB3, BTG2 and FASN genes in the subcutaneous adipose and Longissimus dorsi muscle tissues of purebred and crossbred Australian sheep. JOURNAL OF ANIMAL SCIENCE AND TECHNOLOGY 2015; 57:8. [PMID: 26290728 PMCID: PMC4540301 DOI: 10.1186/s40781-015-0047-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Accepted: 02/12/2015] [Indexed: 01/27/2023]
Abstract
BACKGROUND The demand for healthy, lean and consistent meat products containing low saturated fatty acid content and high quality polyunsaturated fatty acids (PUFA), especially long-chain (≥C20) omega-3 PUFA, has increased in recent times. Fat deposition is altered by both the genetic background and dietary supplements, and this study aimed to assess the effect of dietary Spirulina supplementation levels on the mRNA expression patterns of genes controlling lipid metabolism in the subcutaneous adipose tissue (SAT) and Longissimus dorsi (ld) muscle of Australian crossbred sheep. METHODS Twenty-four weaned lambs belonging to four breeds under the same management conditions were maintained on ryegrass pasture and fed three levels of Spirulina supplement (control, low and high). In terms of nutrient composition, Spirulina is a nutrient-rich supplement that contains all essential amino acids, vitamins and minerals. It also is a rich source of carotenoids and fatty acids, especially gamma-linolenic acid (GLA) that infer health benefits. After slaughter, subcutaneous adipose tissue (SAT) and ld samples were subjected to mRNA extraction and reverse transcription using quantitative polymerase chain reaction (RT-qPCR) to assess the mRNA expression levels of the Aralkylamine N-acetyltransferase (AANAT), Adrenergic beta-3 receptor (ADRB3), B-cell translocation gene 2 (BTG2) and Fatty acid synthase (FASN) genes, which are associated with lipid metabolism. RESULTS Both low and high Spirulina supplementation levels strongly up-regulated the transcription of all the selected genes in both SAT and ld tissues (mostly in the subcutaneous adipose), but sheep breed and sex did not influence the gene expression patterns in these tissues. CONCLUSIONS The evidence indicates that high Spirulina supplementation level resulted in a decrease in intramuscular fat content in Australian purebred and crossbred sheep due to the enhanced production of melatonin in sheep muscle tissues and strong up-regulation of mRNA expression of BTG2 in SAT which negatively affected fat deposition. In contrast, low Spirulina supplementation level strongly up-regulated the ADRB3 and FASN genes responsible for fat production. These findings are consistent with the observed phenotypic data suggesting that low Spirulina supplementation level can increase lamb production, with higher long-chain PUFA content.
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Affiliation(s)
- Arash Kashani
- />Animal Science and Genetics, Tasmanian Institute of Agriculture, School of Land and Food, Faculty of Science, Engineering and Technology, University of Tasmania, Private Bag 54 Sandy Bay, Hobart, Tasmania 7001 Australia
| | - Benjamin William Behrens Holman
- />New South Wales Department of Primary Industries, Centre for Red Meat and Sheep Development, Cowra, 2794 New South Wales Australia
| | - Peter David Nichols
- />CSIRO Food and Nutrition, Oceans and Atmosphere Flagships, Hobart, TAS 7001, Australia
| | - Aduli Enoch Othniel Malau-Aduli
- />Animal Science and Genetics, Tasmanian Institute of Agriculture, School of Land and Food, Faculty of Science, Engineering and Technology, University of Tasmania, Private Bag 54 Sandy Bay, Hobart, Tasmania 7001 Australia
- />Veterinary and Biomedical Sciences, College of Public Health, Medical and Veterinary Sciences, Division of Tropical Health and Medicine, James Cook University, Townsville, Queensland 4811 Australia
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Ware JV, Nelson OL, Robbins CT, Carter PA, Sarver BAJ, Jansen HT. Endocrine rhythms in the brown bear (Ursus arctos): Evidence supporting selection for decreased pineal gland size. Physiol Rep 2013; 1:e00048. [PMID: 24303132 PMCID: PMC3835004 DOI: 10.1002/phy2.48] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Revised: 07/09/2013] [Accepted: 07/10/2013] [Indexed: 12/21/2022] Open
Abstract
Many temperate zone animals adapt to seasonal changes by altering their physiology. This is mediated in large part by endocrine signals that encode day length and regulate energy balance and metabolism. The objectives of this study were to determine if the daily patterns of two important hormones, melatonin and cortisol, varied with day length in captive brown bears (Ursus arctos) under anesthetized and nonanesthetized conditions during the active (March-October) and hibernation periods. Melatonin concentrations varied with time of day and season in nonanesthetized female bears despite exceedingly low nocturnal concentrations (1-4 pg/mL) in the active season. In contrast, melatonin concentrations during hibernation were 7.5-fold greater than those during the summer in anesthetized male bears. Functional assessment of the pineal gland revealed a slight but significant reduction in melatonin following nocturnal light application during hibernation, but no response to beta-adrenergic stimulation was detected in either season. Examination of pineal size in two bear species bears combined with a phylogenetically corrected analysis of pineal glands in 47 other species revealed a strong relationship to brain size. However, pineal gland size of both bear species deviated significantly from the expected pattern. Robust daily plasma cortisol rhythms were observed during the active season but not during hibernation. Cortisol was potently suppressed following injection with a synthetic glucocorticoid. The results suggest that melatonin and cortisol both retain their ability to reflect seasonal changes in day length in brown bears. The exceptionally small pineal gland in bears may be the result of direct or indirect selection.
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Affiliation(s)
- Jasmine V Ware
- Departments of Integrative Physiology and Neuroscience, College of Veterinary Medicine, Washington State University Pullman, Washington, 99164
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Rovsing L, Clokie S, Bustos DM, Rohde K, Coon SL, Litman T, Rath MF, Møller M, Klein DC. Crx broadly modulates the pineal transcriptome. J Neurochem 2011; 119:262-74. [PMID: 21797868 DOI: 10.1111/j.1471-4159.2011.07405.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Cone-rod homeobox (Crx) encodes Crx, a transcription factor expressed selectively in retinal photoreceptors and pinealocytes, the major cell type of the pineal gland. In this study, the influence of Crx on the mammalian pineal gland was studied by light and electron microscopy and by use of microarray and qRTPCR technology, thereby extending previous studies on selected genes (Furukawa et al. 1999). Deletion of Crx was not found to alter pineal morphology, but was found to broadly modulate the mouse pineal transcriptome, characterized by a>2-fold down-regulation of 543 genes and a>2-fold up-regulation of 745 genes (p<0.05). Of these, one of the most highly up-regulated (18-fold) was Hoxc4, a member of the Hox gene family, members of which are known to control gene expression cascades. During a 24-h period, a set of 51 genes exhibited differential day/night expression in pineal glands of wild-type animals; only eight of these were also day/night expressed in the Crx⁻/⁻ pineal gland. However, in the Crx⁻/⁻ pineal gland 41 genes exhibited differential night/day expression that was not seen in wild-type animals. These findings indicate that Crx broadly modulates the pineal transcriptome and also influences differential night/day gene expression in this tissue. Some effects of Crx deletion on the pineal transcriptome might be mediated by Hoxc4 up-regulation.
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Affiliation(s)
- Louise Rovsing
- Department of Neuroscience and Pharmacology, Panum Institute, University of Copenhagen, Copenhagen, Denmark
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Plasma melatonin in domestic female Mediterranean sheep (Comisana breed) and goats (Maltese and Red Syrian). Res Vet Sci 2010; 90:35-9. [PMID: 20542527 DOI: 10.1016/j.rvsc.2010.05.013] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2009] [Revised: 03/18/2010] [Accepted: 05/11/2010] [Indexed: 11/22/2022]
Abstract
The plasma melatonin nychtemeral profiles in Mediterranean ewes and goats were evaluated six times throughout the year. Melatonin levels were high throughout the night and generally below the assay detection limit during daytime. However, during long days, 30% of the last daytime samples had high melatonin concentrations. Plasma melatonin levels were higher in Comisana sheep than in goats, and higher in Maltese than in Red Syrian goats, with highly significant effect of the individual animal and high repeatability. Plasma melatonin was higher in April than in August. When there was a large difference between the duration of day and night, the plasma melatonin pattern and the light/dark cycle did not always match exactly, suggesting some form of superimposition and/or the prevalence of an endogenous rhythm. The difference found at similar scotoperiods with increasing or decreasing day length may be involved in the perception of the photoperiodic changes.
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Melatonin secretion during postnatal development in wild and domestic female lambs. Anim Reprod Sci 2010; 119:24-30. [PMID: 20060240 DOI: 10.1016/j.anireprosci.2009.12.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2009] [Revised: 12/02/2009] [Accepted: 12/07/2009] [Indexed: 11/20/2022]
Abstract
This study examines the patterns of melatonin secretion during postnatal development in wild (mouflon; n = 7) and domestic (Spanish Merino; n = 6) female lambs under their natural photoperiod conditions. The aim was to determine whether these types of sheep which differ in the timing of puberty, also differ in the establishment of daily melatonin secretory rhythms and/or in the nocturnal plasma melatonin secretion. In addition, the time when the lambs first reached nocturnal levels of melatonin similar to adults was also evaluated. For this purpose, the melatonin secretion in lambs was compared with those of their mothers. A day/night (D/N) difference in plasma melatonin concentration was noticed as early as 1 day after birth in the Merino female lambs (D: 5.9 +/- 1.0 pg/ml compared to N: 22.0 +/- 3.3 pg/ml; p < 0.05), and by 1 week after birth in the mouflon female lambs (D: 4.9 +/- 0.3 pg/ml compared to N: 56.9 +/- 15.3 pg/ml; p < 0.05). An effect of the genotype (p < 0.05) and age (p < 0.01) was detected on mean nocturnal plasma melatonin concentrations, which were lower in the Merino than in the mouflon lambs. Night-time plasma concentration of melatonin was also high in mouflon than in Merino mothers (p < 0.05). No differences were detected between the wild genotype and the domestic one in the time when the lambs first reached nocturnal levels of melatonin similar to those of their mothers.
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Vera LM, Davie A, Taylor JF, Migaud H. Differential light intensity and spectral sensitivities of Atlantic salmon, European sea bass and Atlantic cod pineal glands ex vivo. Gen Comp Endocrinol 2010; 165:25-33. [PMID: 19501092 DOI: 10.1016/j.ygcen.2009.05.021] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/26/2008] [Revised: 03/23/2009] [Accepted: 05/27/2009] [Indexed: 10/20/2022]
Abstract
Photoperiod is perceived by pineal photoreceptors and transduced into rhythmic melatonin signals. These rhythms can be influenced by light intensity and spectral content. In this study we compared the light sensitivity of Atlantic salmon, European sea bass and Atlantic cod by testing ex vivo the effect of different intensities and narrow bandwidth lights on nocturnal melatonin suppression by isolated pineal glands in a flow-through culture system. Using combinations of neutral density and bandpass interference filters we tested a range of light intensities (ranging from 1.22x10(13) to 3.85x10(6) photons s(-1) cm(-2)) and three wavelengths of 80 nm width (472, 555 and 661 nm corresponding to blue, green and red, respectively). Results showed clear species specific light intensity and spectral sensitivities, with cod being from 100 to 1000 times more sensitive than sea bass and salmon. Regarding the influence of spectrum, red light was less efficient on suppressing melatonin than blue and green in salmon but results were not as clear in the two other species studied. Finally, the first evidence of relative photoreception in teleosts was obtained in cod suggesting that the definition of illuminance thresholds (day/night perception) would depend on the day intensity. Indeed, a single order of magnitude increase or decrease in day intensity was shown to elicit a significant shift in the intensity response curve of night-time melatonin suppression. Taken together, this study demonstrated species specific light intensity and spectral sensitivities within temperate teleosts.
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Affiliation(s)
- L M Vera
- Institute of Aquaculture, University of Stirling, Stirling, UK
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Coelho LA, Rodrigues PA, Nonaka KO, Sasa A, Balieiro JCC, Vicente WRR, Cipolla-Neto J. Annual pattern of plasma melatonin and progesterone concentrations in hair and wool ewe lambs kept under natural photoperiod at lower latitudes in the southern hemisphere. J Pineal Res 2006; 41:101-7. [PMID: 16879314 DOI: 10.1111/j.1600-079x.2006.00333.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
To study the annual pattern of plasma melatonin and progesterone concentrations in hair [Santa Inês (SI)] and wool [Romney Marsh (RM) and Suffolk (SU)] ewe lambs kept under natural photoperiods at 21 degrees 59'S, 12 ewe lambs (four/breed) were used. For melatonin, blood samples were collected monthly throughout the year at the onset (17:00, 19:00 and 21:00 hr) and end (04:00, 06:00 and 08:00 hr) of the night, and for progesterone the samples were collected in the morning, two to three times a week throughout the year. Plasma melatonin concentrations at different times of the day changed according to the season. In diurnal periods (17:00 and 8:00 hr) no seasonal differences were observed but they became evident in the nocturnal intervals (21:00 and 4:00 hr) and transitional night-day (6:00 hr) times. The patterns of melatonin secretion were higher in winter and autumn than in spring and summer. The patterns of plasma progesterone secretion were affected by interaction between breed and season. There was no seasonal variation in plasma progesterone concentrations for SI females. The progesterone pattern for RM and SU females varied with season. The plasma levels were higher in autumn and winter than in spring and summer. At 21 degrees 59'S hair and wool ewe lambs showed the same annual pattern of plasma melatonin concentration while the annual progesterone profiles were quite different. For SI females this pattern was constant along all seasons and for RM and SU females this pattern was higher during autumn and winter than spring and summer.
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Affiliation(s)
- L A Coelho
- Department of Animal Science, FZEA-USP, Pirassununga-SP, Brazil.
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Peltoniemi OAT, Tast A, Virolainen JV, Karkamo V, Heinonen M, Andersson MA. Night-time Melatonin Secretion and Seasonally Delayed Puberty in Gilts. Reprod Domest Anim 2005; 40:224-7. [PMID: 15943696 DOI: 10.1111/j.1439-0531.2005.00582.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
This study was conducted to determine whether the seasonal delay in puberty in autumn is driven by individual differences in night-time melatonin secretion in domestic gilts at the attainment of puberty. A group of spring-born gilts (n = 30) were expected to reach puberty in autumn by the age of 7 months. Eighteen of these gilts were selected in pairs on the basis of matched days of birth. By the expected time, half of the animals showed oestrous symptoms (group CYCLING, n = 9) with the rest remaining silent (group SILENT, n = 9). Afterwards, all gilts were fitted with indwelling jugular catheters for frequent blood sampling. Blood samples were collected from all animals three times during the day followed by three times in the night at 2-h intervals for 48 h. The samples were analysed by a commercial radioimmunoassay (RIA). The results show a consistent 25-fold rise (on average) in night-time melatonin concentration in every animal sampled with group averages ranging from 0.28 +/- 0.04 to 0.37 +/- 0.06 pg/ml at day and from 10.20 +/- 2.16 to 10.67 +/- 0.05 pg/ml at night. Night-time group mean values between CYCLING and SILENT gilts did not differ significantly (10.26 +/- 0.67 and 10.38 +/- 0.94 for the CYCLING; 10.67 +/- 0.05 and 10.20 +/- 2.16 for the SILENT). When 10 pg/ml was used as a threshold value, six individuals did not reach it during the night (low responders). Two of these gilts were CYCLING and four were SILENT. In conclusion, the results presented imply no involvement of the level of night-time melatonin concentration in the seasonal delay of puberty in gilts.
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Affiliation(s)
- O A T Peltoniemi
- Faculty of Veterinary Medicine, Department of Clinical Veterinary Sciences, University of Helsinki, Saarentaus, Finland.
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Ganguly S, Weller JL, Ho A, Chemineau P, Malpaux B, Klein DC. Melatonin synthesis: 14-3-3-dependent activation and inhibition of arylalkylamine N-acetyltransferase mediated by phosphoserine-205. Proc Natl Acad Sci U S A 2005; 102:1222-7. [PMID: 15644438 PMCID: PMC544185 DOI: 10.1073/pnas.0406871102] [Citation(s) in RCA: 172] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2004] [Indexed: 11/18/2022] Open
Abstract
The nocturnal increase in circulating melatonin in vertebrates is regulated by the activity of arylalkylamine N-acetyltransferase (AANAT), the penultimate enzyme in the melatonin pathway (serotonin --> N-acetylserotonin --> melatonin). Large changes in activity are linked to cyclic AMP-dependent protein kinase-mediated phosphorylation of AANAT T31. Phosphorylation of T31 promotes binding of AANAT to the dimeric 14-3-3 protein, which activates AANAT by increasing arylalkylamine affinity. In the current study, a putative second AANAT cyclic AMP-dependent protein kinase phosphorylation site, S205, was found to be approximately 55% phosphorylated at night, when T31 is approximately 40% phosphorylated. These findings indicate that ovine AANAT is dual-phosphorylated. Moreover, light exposure at night decreases T31 and S205 phosphorylation, consistent with a regulatory role of both sites. AANAT peptides containing either T31 or S205 associate with 14-3-3zeta in a phosphorylation-dependent manner; binding through phosphorylated (p)T31 is stronger than that through pS205, consistent with the location of only pT31 in a mode I binding motif, one of two recognized high-affinity 14-3-3-binding motifs AANAT protein binds to 14-3-3zeta through pT31 or pS205. Two-site binding lowers the Km for arylalkylamine substrate to approximately 30 microM. In contrast, single-site pS205 binding increases the Km to approximately 1,200 microM. Accordingly, the switch from dual to single pS205 binding of AANAT to 14-3-3 changes the Km for substrates by approximately 40-fold. pS205 seems to be part of a previously unrecognized 14-3-3-binding motif-pS/pT (X1-2)-COOH, referred to here as mode III.
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Affiliation(s)
- Surajit Ganguly
- Section on Neuroendocrinology, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892-4480, USA
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Malpaux B, Migaud M, Tricoire H, Chemineau P. Biology of mammalian photoperiodism and the critical role of the pineal gland and melatonin. J Biol Rhythms 2001; 16:336-47. [PMID: 11506379 DOI: 10.1177/074873001129002051] [Citation(s) in RCA: 248] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
In mammals, photoperiodic information is transformed into a melatonin secretory rhythm in the pineal gland (high levels at night, low levels during the day). Melatonin exerts its effects in discrete hypothalamic areas, most likely through MT1 melatonin receptors. Whether melatonin is brought to the hypothalamus from the cerebrospinal fluid or the blood is still unclear. The final action of this indoleamine at the level of the central nervous system is a modulation of GnRH secretion but it does not act directly on GnRH neurones; rather, its action involves a complex neural circuit of interneurones that includes at least dopaminergic, serotoninergic and aminoacidergic neurones. In addition, this network appears to undergo morphological changes between seasons.
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Affiliation(s)
- B Malpaux
- UMR 6073 INRA-CNRS-Université François Rabelais, Physiologie de la Reproduction et des Comportements, Nouzilly, France.
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