Drareg
Member
- Joined
- Feb 18, 2016
- Messages
- 4,772
I got the idea of grey hair being caused by melatonin from Peats article on Aging Eyes, Infant Eyes, and Excitable Tissues,he mentions animal hair colour changes with light.
It seems at this point their are many ways to influence grey hair from research posted on here,this is another angle I wanted to highlight if anybody ever gets anymore info on it,it seems to be the one thing we haven't achieved on here or through Peats work is reversal of grey hair,surely this is a potent sign of improving health. In relation to the tryptophan-serotonin link to grey hair we could apply the same thinking to tryptophan and melatonin relationship.
Another question is why do we loose head hair if it's a low energy adaption as speculated,it would make more sense for the body to keep the hair as warmth for the brain and loose all the other body hair like facial ,arm and pubic first?
I understand nature doesn't evolve perfectly and we have some strange adaptions that take the Long way round.
Quote from Peats article-
"In snowy climates, it’s “ecologically” rational for animals to turn white in the winter, for camouflage. But tadpoles also turn white in the dark, or under the influence of melatonin, and the biological meaning of that isn’t so clear. It’s possible that being white would reduce their loss of heat through radiation, but I think it is more likely that it relates to an increased ability of weak radiation to penetrate their tissues, rather than being stopped near the surface by the melanin in the skin. The absence of melanin makes them more sensitive to light. Bright light suppresses their melatonin, and makes them turn dark brown or black, and this protects them from bright sunlight."
Below study on melatonin and hair.
"Abstract
Melatonin, the pineal gland hormone and a strong antioxidant, has long been known, particularly in animal-experiment based research and the wool-producing industry, to be a potent regulatory neuroendocrine substance in relation to hair growth, hair color and hair cycle, depending on light periods, seasonal rhythms, environmental factors and reproductive rhythms. Nevertheless, the biological mechanisms of this extremely versatile hormone, especially with regard to human hair follicles, are not fully understood. In recent years, however, essential knowledge has been gained on the melatoninergic system of the skin, melatonin levels in keratinocytes and hair follicles, extrapineal intrafollicular melatonin synthesis and noradrenalin-induced increase in synthesis, as well as hair cycle-dependent expression of the membrane-bound melatonin receptor MT2 and the nuclear receptor RORalpha. Functional data on the growth of human hair both in vitro and in vivo show that melatonin might play an essential role in hair physiology."
[The influence of melatonin on hair physiology]. - PubMed - NCBI
Abstract
The expression of retinoid-acid-related orphan receptor α (RORα) was evaluated at the mRNA level using real-time polymerase chain reaction (qRT-PCR), and its expression localization was determined by in situ hybridization of adult Inner Mongolian cashmere goats at different times of the year. In situ hybridization demonstrated that RORαwas expressed in secondary hair follicles of the hair shaft, inner root sheath, outer root sheath, medulla, and other parts that are target organs of the RORαreceptor gene. qRT-PCR results showed that there was no significant difference in the RORa mRNA abundance in February, April, August, and October (P > 0.05), and the only difference occurred in December relative to February, August, and October (P < 0.05). This difference revealed that melatonin possibly promotes cashmere growth through the nuclear receptor RORα. This study provides a good foundation for future studies on the relationship between the melatoninreceptor and cashmere growth; in addition, it provides new insights for increased cashmere production and quality.
Expression of the RORα gene in Inner Mongolian cashmere goat hair follicles. - PubMed - NCBI
Abstract
Seasonal responses of many animal species are triggered by changes in daylength and its transduction into a neuroendocrine signal by the pineal gland through the nocturnal duration of melatonin (MEL) release. The precise central sites necessary to receive, transduce, and relay the short day (SD) fall-winter MEL signals into seasonal responses and changes in physiology and behavior are unclear. In Siberian hamsters, SDs trigger decreases in body and lipid mass, testicular regression and pelage color changes. Several candidate genes and their central sites of expression have been proposed as components of the MEL transduction system with considerable recent focus on the arcuate nucleus (ARC) and its component, the dorsomedial posterior arcuate nucleus (dmpARC). This site has been postulated as a critical relay of SD information through the modulation of a variety of neurochemicals/receptors important for the control of energy balance. Here the necessity of an intact dmpARC for SD responses was tested by making electrolytic lesions of the Siberian hamster dmpARC and then exposing them to either long days (LD) or SDs for 12wks. The SD typical decreases in body and fat mass, food intake, testicular volume, serum testosterone concentrations, pelage color change and increased UCP-1 protein expression (a proxy for brown adipose tissue thermogenesis) all occurred despite the lack of an intact dmpARC. Although the Siberian hamster dmpARC contains photoperiod-modulated constituents, these data demonstrate that an intact dmpARC is not necessary for SD responses and not integral to the seasonal energy- and reproductive-related responses measured here.
An intact dorsomedial posterior arcuate nucleus is not necessary for photoperiodic responses in Siberian hamsters. - PubMed - NCBI
Potentially Interesting in relation how the muzzle of animals and humans can go grey early?
"Evaluating individual circadian rhythm traits is crucial for understanding the human biological clock system. The present study reports characterization of physiological and molecular parameters in 13 healthy male subjects under a constant routine condition, where interfering factors were kept to minimum. We measured hormonal secretion levels and examined temporal expression profiles of circadian clock genes in peripheral leukocytes and beard hair follicle cells. All 13 subjects had prominent daily rhythms in melatonin and cortisol secretion. Significant circadian rhythmicity was found for PER1 in 9 subjects, PER2 in 3 subjects, PER3 in all 13 subjects, and BMAL1 in 8 subjects in leukocytes. Additionally, significant circadian rhythmicity was found for PER1 in 5 of 8 subjects tested, PER2 in 2 subjects, PER3 in 6 subjects, and BMAL1 in 3 subjects in beard hair follicle cells. The phase of PER1 and PER3 rhythms in leukocytes correlated significantly with that of physiological rhythms. Our results demonstrate that leukocytes and beard hair follicle cells possess an endogenous circadian clock and suggest that PER1 and PER3 expression would be appropriate biomarkers and hair follicle cells could be a useful tissue source for the evaluation of biological clock traits in individuals."
Rhythmic expression of circadian clock genes in human leukocytes and beard hair follicle cells. - PubMed - NCBI
"
Abstract
The role of neurohormones and neuropeptides in human hair follicle (HF) pigmentation extends far beyond the control of melanin synthesis by α-MSH and ACTH and includes melanoblast differentiation, reactive oxygen species scavenging, maintenance of HF immune privilege, and remodeling of the HF pigmentary unit (HFPU). It is now clear that human HFs are not only a target of multiple neuromediators, but also are a major non-classical production site for neurohormones such as CRH, proopiomelanocortin, ACTH, α-MSH, ß-endorphin, TRH, and melatonin. Moreover, human HFs have established a functional peripheral equivalent of the hypothalamic-pituitary-adrenal axis. By charting the author's own meanderings through the jungle of hair pigmentation research, the current perspectives essay utilizes four clinical observations - hair repigmentation, canities, poliosis, and 'overnight greying'- as points of entry into the enigmas and challenges of .pigmentary HF neuroendocrinology. After synthesizing key principles and defining major open questions in the field, selected research avenues are delineated that appear clinically most promising. In this context, novel neuroendocrinological strategies to retard or reverse greying and to reduce damage to the HFPU are discussed.
A neuroendocrinological perspective on human hair follicle pigmentation. - PubMed - NCBI
Abstract
Melatonin, the chief secretory product of the pineal gland, has long been known to modulate hair growth, pigmentation and/or molting in many species, presumably as a key neuroendocrine regulator that couples coat phenotype and function to photoperiod-dependent environmental and reproductive changes. However, the detailed effects and mechanisms of this surprisingly pleiotropic indole on the hair follicle (HF) regarding growth control and pigmentation have not yet been completely understood. While unspecific melatonin binding sites have long been identified (e.g., in goat and mouse HFs), specific melatonin membrane MT2 receptor transcripts and both protein and mRNA expression for a specific nuclear melatonin binding site [retinoid-related orphan receptor alpha (RORalpha)] have only recently been identified in murine HFs. MT1, known to be expressed in human skin cells, is not transcribed in mouse skin. After initial enzymologic data from hamster skin related to potential intracutaneous melatonin synthesis, it has recently been demonstrated that murine and human skin, namely human scalp HFs in anagen, are important sites of extrapineal melatonin synthesis. Moreover, HF melatonin production is enhanced by catecholamines (as it classically occurs in the pineal gland). Melatoninmay also functionally play a role in hair-cycle control, as it down-regulates both apoptosis and estrogen receptor-alpha expression, and modulates MT2 and RORalpha expression in murine skin in a hair-cycle-dependent manner. Because of melatonin's additional potency as a free radical scavenger and DNA repair inducer, the metabolically and proliferatively highly active anagen hair bulb may also exploit melatonin synthesis in loco as a self-cytoprotective strategy.
Melatonin and the hair follicle. - PubMed - NCBI
To assess the genetic variability in both the nocturnal increase pattern of melatonin concentration and photoresponsiveness in coat changes, an experiment on 422 Rex rabbits (from 23 males) raised under a constant light programme from birth was performed. The animals were sampled at 12 weeks of age, according to 4 periods over a year. Blood samples were taken 7 times during the dark phase and up to 1 h after the lighting began. Maturity of the fur was assessed at pelting. Heritability estimates of blood melatoninconcentration (0.42, 0.17 and 0.11 at mid-night, 13 and 15 h after lights-out respectively) and strong genetic correlations between fur maturity and melatonin levels at the end of the dark phase (-0.64) indicates that (i) the variability of the nocturnal pattern of melatonin levels is under genetic control and (ii) the duration of the nocturnal melatonin increase is a genetic component of photoresponsiveness in coat changes.
Genetic variability of the pattern of night melatonin blood levels in relation to coat changes development in rabbits. - PubMed - NCBI
Below slightly off topic but interesting.
"Abstract
Research into how the central nervous system (CNS) and the skin of mammals are physiologically connected and how this "brain-skin connection" may be therapeutically targeted in clinical medicine has witnessed a renaissance. A key element in this development has been the discovery that mammalian skin and its appendages, namely human scalp hair follicles (HFs), not only are important, long-underestimated target tissues for classical neurohormones, neurotrophins and neuropeptides, but also are eminent peripheral tissue sources for the production and/or release of these neuromediators. This essay summarizes the many different levels of biology at which human scalp HFs respond to and generate a striking variety of neurohormones, and portrays HFs as prototypic, cyclically remodelled miniorgans that utilize these neurohormones to autoregulate their growth, hair shaft production, rhythmic organ transformation, pigmentation, mitochondrial energy metabolism, and immune status. The essay also explores how preclinical research on human scalp HFs can be exploited to unveil and explore "novel" and clinically as yet untapped, but most likely ancestral functions of neurohormones within mammalian epithelial biology that still impact substantially on human skin physiology. Arguably, systematic investigation of the "brain-skin connection" is one of the most intriguing current research frontiers in investigative dermatology, not the least since it has reversed the traditional CNS focus in studying the interactions between two key organ systems by placing the skin epithelium on center stage."
Exploring the "brain-skin connection": Leads and lessons from the hair follicle. - PubMed - NCBI
It seems at this point their are many ways to influence grey hair from research posted on here,this is another angle I wanted to highlight if anybody ever gets anymore info on it,it seems to be the one thing we haven't achieved on here or through Peats work is reversal of grey hair,surely this is a potent sign of improving health. In relation to the tryptophan-serotonin link to grey hair we could apply the same thinking to tryptophan and melatonin relationship.
Another question is why do we loose head hair if it's a low energy adaption as speculated,it would make more sense for the body to keep the hair as warmth for the brain and loose all the other body hair like facial ,arm and pubic first?
I understand nature doesn't evolve perfectly and we have some strange adaptions that take the Long way round.
Quote from Peats article-
"In snowy climates, it’s “ecologically” rational for animals to turn white in the winter, for camouflage. But tadpoles also turn white in the dark, or under the influence of melatonin, and the biological meaning of that isn’t so clear. It’s possible that being white would reduce their loss of heat through radiation, but I think it is more likely that it relates to an increased ability of weak radiation to penetrate their tissues, rather than being stopped near the surface by the melanin in the skin. The absence of melanin makes them more sensitive to light. Bright light suppresses their melatonin, and makes them turn dark brown or black, and this protects them from bright sunlight."
Below study on melatonin and hair.
"Abstract
Melatonin, the pineal gland hormone and a strong antioxidant, has long been known, particularly in animal-experiment based research and the wool-producing industry, to be a potent regulatory neuroendocrine substance in relation to hair growth, hair color and hair cycle, depending on light periods, seasonal rhythms, environmental factors and reproductive rhythms. Nevertheless, the biological mechanisms of this extremely versatile hormone, especially with regard to human hair follicles, are not fully understood. In recent years, however, essential knowledge has been gained on the melatoninergic system of the skin, melatonin levels in keratinocytes and hair follicles, extrapineal intrafollicular melatonin synthesis and noradrenalin-induced increase in synthesis, as well as hair cycle-dependent expression of the membrane-bound melatonin receptor MT2 and the nuclear receptor RORalpha. Functional data on the growth of human hair both in vitro and in vivo show that melatonin might play an essential role in hair physiology."
[The influence of melatonin on hair physiology]. - PubMed - NCBI
Abstract
The expression of retinoid-acid-related orphan receptor α (RORα) was evaluated at the mRNA level using real-time polymerase chain reaction (qRT-PCR), and its expression localization was determined by in situ hybridization of adult Inner Mongolian cashmere goats at different times of the year. In situ hybridization demonstrated that RORαwas expressed in secondary hair follicles of the hair shaft, inner root sheath, outer root sheath, medulla, and other parts that are target organs of the RORαreceptor gene. qRT-PCR results showed that there was no significant difference in the RORa mRNA abundance in February, April, August, and October (P > 0.05), and the only difference occurred in December relative to February, August, and October (P < 0.05). This difference revealed that melatonin possibly promotes cashmere growth through the nuclear receptor RORα. This study provides a good foundation for future studies on the relationship between the melatoninreceptor and cashmere growth; in addition, it provides new insights for increased cashmere production and quality.
Expression of the RORα gene in Inner Mongolian cashmere goat hair follicles. - PubMed - NCBI
Abstract
Seasonal responses of many animal species are triggered by changes in daylength and its transduction into a neuroendocrine signal by the pineal gland through the nocturnal duration of melatonin (MEL) release. The precise central sites necessary to receive, transduce, and relay the short day (SD) fall-winter MEL signals into seasonal responses and changes in physiology and behavior are unclear. In Siberian hamsters, SDs trigger decreases in body and lipid mass, testicular regression and pelage color changes. Several candidate genes and their central sites of expression have been proposed as components of the MEL transduction system with considerable recent focus on the arcuate nucleus (ARC) and its component, the dorsomedial posterior arcuate nucleus (dmpARC). This site has been postulated as a critical relay of SD information through the modulation of a variety of neurochemicals/receptors important for the control of energy balance. Here the necessity of an intact dmpARC for SD responses was tested by making electrolytic lesions of the Siberian hamster dmpARC and then exposing them to either long days (LD) or SDs for 12wks. The SD typical decreases in body and fat mass, food intake, testicular volume, serum testosterone concentrations, pelage color change and increased UCP-1 protein expression (a proxy for brown adipose tissue thermogenesis) all occurred despite the lack of an intact dmpARC. Although the Siberian hamster dmpARC contains photoperiod-modulated constituents, these data demonstrate that an intact dmpARC is not necessary for SD responses and not integral to the seasonal energy- and reproductive-related responses measured here.
An intact dorsomedial posterior arcuate nucleus is not necessary for photoperiodic responses in Siberian hamsters. - PubMed - NCBI
Potentially Interesting in relation how the muzzle of animals and humans can go grey early?
"Evaluating individual circadian rhythm traits is crucial for understanding the human biological clock system. The present study reports characterization of physiological and molecular parameters in 13 healthy male subjects under a constant routine condition, where interfering factors were kept to minimum. We measured hormonal secretion levels and examined temporal expression profiles of circadian clock genes in peripheral leukocytes and beard hair follicle cells. All 13 subjects had prominent daily rhythms in melatonin and cortisol secretion. Significant circadian rhythmicity was found for PER1 in 9 subjects, PER2 in 3 subjects, PER3 in all 13 subjects, and BMAL1 in 8 subjects in leukocytes. Additionally, significant circadian rhythmicity was found for PER1 in 5 of 8 subjects tested, PER2 in 2 subjects, PER3 in 6 subjects, and BMAL1 in 3 subjects in beard hair follicle cells. The phase of PER1 and PER3 rhythms in leukocytes correlated significantly with that of physiological rhythms. Our results demonstrate that leukocytes and beard hair follicle cells possess an endogenous circadian clock and suggest that PER1 and PER3 expression would be appropriate biomarkers and hair follicle cells could be a useful tissue source for the evaluation of biological clock traits in individuals."
Rhythmic expression of circadian clock genes in human leukocytes and beard hair follicle cells. - PubMed - NCBI
"
Abstract
The role of neurohormones and neuropeptides in human hair follicle (HF) pigmentation extends far beyond the control of melanin synthesis by α-MSH and ACTH and includes melanoblast differentiation, reactive oxygen species scavenging, maintenance of HF immune privilege, and remodeling of the HF pigmentary unit (HFPU). It is now clear that human HFs are not only a target of multiple neuromediators, but also are a major non-classical production site for neurohormones such as CRH, proopiomelanocortin, ACTH, α-MSH, ß-endorphin, TRH, and melatonin. Moreover, human HFs have established a functional peripheral equivalent of the hypothalamic-pituitary-adrenal axis. By charting the author's own meanderings through the jungle of hair pigmentation research, the current perspectives essay utilizes four clinical observations - hair repigmentation, canities, poliosis, and 'overnight greying'- as points of entry into the enigmas and challenges of .pigmentary HF neuroendocrinology. After synthesizing key principles and defining major open questions in the field, selected research avenues are delineated that appear clinically most promising. In this context, novel neuroendocrinological strategies to retard or reverse greying and to reduce damage to the HFPU are discussed.
A neuroendocrinological perspective on human hair follicle pigmentation. - PubMed - NCBI
Abstract
Melatonin, the chief secretory product of the pineal gland, has long been known to modulate hair growth, pigmentation and/or molting in many species, presumably as a key neuroendocrine regulator that couples coat phenotype and function to photoperiod-dependent environmental and reproductive changes. However, the detailed effects and mechanisms of this surprisingly pleiotropic indole on the hair follicle (HF) regarding growth control and pigmentation have not yet been completely understood. While unspecific melatonin binding sites have long been identified (e.g., in goat and mouse HFs), specific melatonin membrane MT2 receptor transcripts and both protein and mRNA expression for a specific nuclear melatonin binding site [retinoid-related orphan receptor alpha (RORalpha)] have only recently been identified in murine HFs. MT1, known to be expressed in human skin cells, is not transcribed in mouse skin. After initial enzymologic data from hamster skin related to potential intracutaneous melatonin synthesis, it has recently been demonstrated that murine and human skin, namely human scalp HFs in anagen, are important sites of extrapineal melatonin synthesis. Moreover, HF melatonin production is enhanced by catecholamines (as it classically occurs in the pineal gland). Melatoninmay also functionally play a role in hair-cycle control, as it down-regulates both apoptosis and estrogen receptor-alpha expression, and modulates MT2 and RORalpha expression in murine skin in a hair-cycle-dependent manner. Because of melatonin's additional potency as a free radical scavenger and DNA repair inducer, the metabolically and proliferatively highly active anagen hair bulb may also exploit melatonin synthesis in loco as a self-cytoprotective strategy.
Melatonin and the hair follicle. - PubMed - NCBI
To assess the genetic variability in both the nocturnal increase pattern of melatonin concentration and photoresponsiveness in coat changes, an experiment on 422 Rex rabbits (from 23 males) raised under a constant light programme from birth was performed. The animals were sampled at 12 weeks of age, according to 4 periods over a year. Blood samples were taken 7 times during the dark phase and up to 1 h after the lighting began. Maturity of the fur was assessed at pelting. Heritability estimates of blood melatoninconcentration (0.42, 0.17 and 0.11 at mid-night, 13 and 15 h after lights-out respectively) and strong genetic correlations between fur maturity and melatonin levels at the end of the dark phase (-0.64) indicates that (i) the variability of the nocturnal pattern of melatonin levels is under genetic control and (ii) the duration of the nocturnal melatonin increase is a genetic component of photoresponsiveness in coat changes.
Genetic variability of the pattern of night melatonin blood levels in relation to coat changes development in rabbits. - PubMed - NCBI
Below slightly off topic but interesting.
"Abstract
Research into how the central nervous system (CNS) and the skin of mammals are physiologically connected and how this "brain-skin connection" may be therapeutically targeted in clinical medicine has witnessed a renaissance. A key element in this development has been the discovery that mammalian skin and its appendages, namely human scalp hair follicles (HFs), not only are important, long-underestimated target tissues for classical neurohormones, neurotrophins and neuropeptides, but also are eminent peripheral tissue sources for the production and/or release of these neuromediators. This essay summarizes the many different levels of biology at which human scalp HFs respond to and generate a striking variety of neurohormones, and portrays HFs as prototypic, cyclically remodelled miniorgans that utilize these neurohormones to autoregulate their growth, hair shaft production, rhythmic organ transformation, pigmentation, mitochondrial energy metabolism, and immune status. The essay also explores how preclinical research on human scalp HFs can be exploited to unveil and explore "novel" and clinically as yet untapped, but most likely ancestral functions of neurohormones within mammalian epithelial biology that still impact substantially on human skin physiology. Arguably, systematic investigation of the "brain-skin connection" is one of the most intriguing current research frontiers in investigative dermatology, not the least since it has reversed the traditional CNS focus in studying the interactions between two key organ systems by placing the skin epithelium on center stage."
Exploring the "brain-skin connection": Leads and lessons from the hair follicle. - PubMed - NCBI
