References: Hair growth and hair loss
Mech Ageing Dev. 1976 Mar-Apr;5(2):109-24.
Patho-physiologic findings after chronic tryptophan deficiency in rats: a model for delayed growth and aging.
Segall PE, Timiras PS.
Long-Evans female rats three weeks, three months and 13-14 months of age were placed on tryptophan-deficient diets for periods ranging from a few months to nearly two years. Growth was interupted during the period of tryptophan-deficiency, but when the animals were returned to a complete diet, they gained weight and grew to normal size. Ability to reproduce, as indicated by litter production, was present at 17-28 months of age in rats which had been deprived of tryptophan, whereas no controls over 17 months of age produced any offspring. Other signs of delayed aging in the experimental group included, at advanced ages, greater longevity, as well as later onset in the appearance of obvious tumors, and better coat condition and hair regrowth. Many of these effects were also seen in pair-fed controls (fed a diet equal in amount to that eaten by the tryptophan-deprived rats, but with 1-tryptophan added). It is hypothesized that tryptophan deficiency delays growth, development and maturation of the central nervous system (CNS), in particular, by decreasing the levels of the neurotransmitter serotonin, for which tryptophan is the necessary precursor. In a parallel experiment, chronic treatment with d, 1-parachlorophenylalanine, an inhibitor of brain serotonin synthesis, from weaning until adulthood, also inhibited growth (body weight) and delayed sexual maturation (age of vaginal opening). These observations suggest that diets deficient in tryptophan or restricted in calories can affect maturation and aging by interfering with CNS protein synthesis, or neurotransmitter metabolism, or both.
online pharmacy ref. source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=933560&dopt=Abstract
Neurotoxicology. 1997;18(3):819-29.
Effects of prenatal methylmercury exposure from a high fish diet on developmental milestones in the Seychelles Child Development Study.
Myers GJ, Davidson PW, Shamlaye CF, Axtell CD, Cernichiari E, Choisy O, Choi A, Cox C, Clarkson TW.
University of Rochester School of Medicine and Dentistry, NY 14642, USA.
Mercury is widespread in the environment and exists in several physical and chemical forms. Prenatal exposure to methylmercury disrupts brain development. The most common mode of prenatal methylmercury exposure is maternal fish consumption. Studies of human prenatal exposure in Iraq following maternal ingestion of methylmercury treated grain suggested that maternal hair mercury concentrations above 10 ppm may be related to delayed developmental milestones and neurological abnormalities. This level of exposure can be achieved by frequent consumption of fish. The Seychelles Child Development Study analyzed developmental milestones similar to those determined in Iraq in a large controlled, prospective study of children exposed prenatally to methylmercury when their mothers ate fish. As part of this ongoing study, cohort children were evaluated at 6.5, 19, 29, and 66 months of age. At 19 months care-givers were asked at what age the child walked (n=720 out of 738) and talked (n=680). Prenatal mercury exposure was determined by atomic absorption analysis of maternal hair segments corresponding to hair growth during the pregnancy. The median mercury level in maternal hair was 5.8 ppm with a range of 0.5-26.7 ppm. The mean age (in months) at walking was 10.7 (SD = 1.9) for females and 10.6 (SD = 2.0) for males. The mean age at talking (in months) was 10.5 (SD = 2.6) for females, and 11.0 (SD = 2.9) for males. After adjusting for covariates and statistical outliers, no association was found between the age at which Seychellois children walked or talked and prenatal exposure to mercury. Normal ages at achievement of the developmental milestones walking and talking were found in Seychellois toddlers following prenatal exposure to methylmercury from a maternal fish diet. These results do not support the lowest effect levels in young children following prenatal methylmercury exposure predicted by the dose response analysis of the Iraq data. More detailed studies in older children are needed to determine if there are adverse effects in fish eating populations.
online pharmacy ref. source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=9339828&dopt=Abstract
Exp Neurol. 1997 Oct;147(2):256-68.
New growth of axons in the cochlear nucleus of adult chinchillas after acoustic trauma.
Bilak M, Kim J, Potashner SJ, Bohne BA, Morest DK.
Department of Anatomy, Center for Neurological Sciences, University of Connecticut Health Center, Farmington 06030, USA.
This study determined the effect of acoustic overstimulation of the adult cochlea on axons in the cochlear nucleus. Chinchillas were exposed to an octave-band noise centered at 4 kHz at 108 dB sound pressure level for 1.75 h. One chinchilla was never exposed to the noise, and several others had one ear protected by an ear plug or prior removal of the malleus and incus. Exposure of unprotected ears caused loss of inner and outer hair cells and myelinated nerve fibers, mostly in the basal half of the cochlea. Cochlear nerve fiber degeneration, ipsilateral to the exposed ears, was traced to regions of the cochlear nucleus representing the damaged parts of the cochlea. In silver impregnations of a deafferented zone in the posteroventral cochlear nucleus, the concentration of axons decreased by 43% after 1 month and by 54% after 2 months. However, by 8 months, the concentration of thinner axons, with diameters of less than 0.46 microm, increased by 46-90% over that at 2 months. The concentration of axons with larger diameters did not change. Between 2 and 8 months small axonal endings appeared next to neuronal cell bodies. This later increase of thinner axons and endings is consistent with a reactive growth of new axons of relatively small diameter. The emergence of small perisomatic boutons suggests that the new axons formed synaptic endings, which might contribute to an abnormal reorganization of the central auditory system and to the pathological changes that accompany acoustic overstimulation.
online pharmacy ref. source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=9344551&dopt=Abstract
Lipitor
Herbs and Pharmaceuticals Online ||
Hair Million herbal formula for hair loss and hair growth ||
Hair growth research references ||