Rat Hair Research Articles

Metabolic Studies on Isolated Hair Follicles: Hair Follicles Engaged in Aerobic Glycolysis and Do Not Demonstrate the Glucose Fatty Acid Cycle

The matrix cells of the hair follicle have one of the highest rates of cell division in the mammalian body, but their fuel metabolism is poorly understood, due mainly to the difficulty in obtaining viable intact follicles from the skin. We have previously shown that viable and intact rat hair follicles can be isolated by shearing, and in this study we now report on their fuel metabolism. In this study we have shown that the hair follicle exhibits aerobic glycolysis, in that of the total glucose utilized by the hair follicle, only 10% is oxidized to CO2. We have also shown that, in the absence of glucose, the hair follicle is capable of utilizing other fuels such as palmitate and beta-hydroxybutyrate. However, neither palmitate or beta-hydroxybutyrate had any effect on the rate of glucose utilization or on [U-14C] glucose oxidation, showing that glucose sparing via the glucose fatty acid cycle does not operate in the hair follicle. Measurements of glucose flux through the pentose phosphate pathway accounted for only 3% of the total glucose utilized by the hair follicle, although this value represented 32% of the total glucose oxidized. Both palmitate and beta-hydroxybutyrate inhibited glucose flux through the pentose phosphate pathway.

Measurement of Nonradioactive Isotopes of Copper in Hair with Inductively Coupled Plasma Mass Spectrometry

A method is reported for tracing dietary enriched (99.61 atom %) nonradioactive 65Cu in rat hair. The method is based on the measurement of the two nonradioactive isotopes of copper (i.e., 63Cu and 65Cu) in rat hair by using inductively coupled plasma mass spectrometry (ICP-MS). Sodium, known to cause interferences in ICP-MS analyses, was removed by using an ion-exchange procedure. Correlation between the diet and hair element concentration levels have been reported. Controversy in the literature exists about the validity of elemental analyses of hair because elements may be incorporated in hair from the diet and body stores during growth, as well as from environmental sources. Tracing dietary elements in hair during growth would eliminate the uncertainness of this procedure. In nature, copper exists as 69.174 atom % 63Cu and 30.826 atom % 65Cu expressed as the 63Cu/65Cu ratio of 2.2400. Enriched (99.61 atom %) 65Cu was obtained and used to label the dietary source of copper. Data showed that 50% of the copper in the rat hair of rats gavaged with the enriched 65Cu isotope was due to 65Cu and 50% was natural isotope-abundant copper.

Effect of Various Dietary Factors on the Deposition of Selenium in the Hair and Nails of Rats

Noninvasive techniques to monitor selenium (Se) status at higher intake levels should be developed if Se supplements are to be given to human subjects as possible anti-cancer agents. Hair and nails have been suggested as indices of Se status because they are easily obtained, transported and stored. However, there has been little research on the potential influence of such factors as dietary Se intake or nutritional status on the levels of Se in hair and nails. Here we report the effects of chemical form of dietary Se and of methionine (Met) status on the Se content of rat hair and nails. Rats were fed diets containing 0.5, 1.5 or 2.5 micrograms/g of Se as sodium selenate (Na2SeO4) or L-selenomethionine (SeMet) for 8 wk. Hair and nail Se retention was two- to threefold greater when dietary SeMet was fed. Hair and nail Se levels increased as liver and muscle Se retention increased in rats fed SeMet, whereas in rats fed Na2SeO4, hair, nails and liver accumulated Se but muscle Se levels remained relatively unchanged. In a second experiment, rats were fed diets containing 0.1, 0.5 or 2.5 micrograms/g of Se as Na2SeO4 or SeMet, +/- added Met (0.3%) for 6 (+Met) or 7 (-Met) wk. Hair and nail Se retention was greater when Met was deficient than when this amino acid was not limiting. These results suggest that factors other than dietary Se intake affect hair and nail Se content and that these tissues should be used with caution for Se status assessment purposes.

Brown‐colored deposits on hair of female rats chronically exposed to 60‐Hz electric fields

An increased incidence and severity of a brownish coloration of hair has been observed around the nose and on the ears of female rats that were chronically exposed to 60-Hz electric fields. Microscopic examination of the colored areas revealed a red-brown globular deposit on hair shafts in affected areas without signs of physical injury.

SEM studies on age related changes in the surface structures of rat hairs

In albino rats of four age groups (male and female; 1, 6, 12 and 36 months) telogen hairs of the back were investigated in scanning electron microscopy at defined locations. The length of the cuticular ‘scales’ as well as the thickness of the hair shaft decreased significantly in the 36 month group of both sexes. In addition the scales of this group had irregular contours, cracks and spindle shaped inclusions.

Studies on the biochemistry and morphology of freshly isolated and maintained rat hair follicles

We have already shown that shearing can be used to yield large numbers of viable intact hair follicles. We now show that these follicles can be viably maintained on permeable supports for 7 days in vitro as determined by their adenine nucleotide contents, rates of [methyl-3H]thymidine and [U-14C]leucine uptake, [methyl-3H]thymidine autoradiography, patterns of keratin synthesis and light and electron microscopy. These studies, however, show that after 7 days maintenance the morphology of maintained follicles shows a closer resemblance to the telogen rather than the anagen follicle. We therefore conclude that the failure of previous attempts at maintaining hair growth in culture is due to hair follicles prematurely entering the resting stage of their hair growth cycle, possibly as a response to isolation.

Extraction of Light Filth from Spirulina Powders and Tablets: Collaborative Study

Results are reported for a collaborative study of a method for the extraction of light filth from spirulina (a blue-green alga) powder and tablets. A 50 g portion of either powder or tablets is dispersed in water, and then boiled with dilute HCI solution. Hairs and insect fragments are isolated by wet sieving on a No. 230 sieve, flotation with mineral oil, and washings of the mineral oil in a percolator. Average recoveries by 12 collaborators for tablets and powders were 70.6 and 70.2%, respectively, for 10 rat hair spikes and 68.3 and 84.4%, respectively, for 20 insect fragment spikes. The method has been approved interim official first action.

Enriched copper isotope tracer for dietary copper incorporation into hair using neutron activation analysis in conjunction with direct-current argon plasma spectrometry

A method is described for labeling and measuring the incorporation of dietary copper into hair using the enriched (99.61 atomic-%) 65Cu isotope. Natural isotope abundant copper exists as 65Cu (30.86 atomic-%) and 63Cu (69.17 atomic-%), but enriched (99.61 atomic-%) 65Cu isotope may be obtained commercially and administered to change deliberately the natural isotope abundance of copper to “label” the copper source. Natural isotope abundant copper and the enriched (99.61 atomic-%) 65Cu isotope were mixed into rat feed and administered daily by gavage. The isotope concentration was determined by neutron activation analysis (NAA). The copper concentration was determined by direct-current argon plasma (DCP) spectrometry. The measured copper isotope ratios ( 65Cu/Cu tot)_for the natural isotope abundant copper in National Bureau of Standards Standard Reference Materials (NBS SRM) 1571 Orchard Leaves and 1577a Bovine Liver were 0.3201 ± 0.0039 and 0.3187 ± 0.0089, respectively. Measured copper isotope ratios in rat hair were 0.3100 ± 0.0606, 0.4580 ± 0.2495 and 0.2712 ± 0.0645 from rats given a standard feed that contained natural isotope abundant copper, a daily supplement of natural isotope abundant copper sulfate mixed into the standard feed and a daily supplement of copper sulfate administered by gavage, respectively. The copper isotope ratio increased to 0.5251 ± 0.2860 and 0.7235 ± 0.0704 in hair from rats given enriched 65Cu in their feed and by gavage, respectively. The statistically significant increase in the 65Cu isotope when administered by gavage demonstrates strates successful labeling of dietary copper in the hair.

Combined biochemical and immunochemical comparison of peptidylarginine deiminases present in various tissues

We have performed a combined biochemical and immunochemical study on the identity of peptidylarginine deiminases (EC 3.5.3.15) present in various mammalian tissues. First, we purified peptidylarginine deiminase from rat skeletal muscle. It gave a single band of molecular weight 83 000 in sodium dodecyl sulfate polyacrylamide gel electrophoresis. Next we immunized rabbits with the purified enzyme. The resulting antibodies reacted specifically with the antigen in Western blot assay. Most of the enzyme activities present in rat skeletal muscle, brain, spinal cord, submaxillary gland and spleen could be characterized as the same muscle-type enzyme by immunoprecipitation and Western blot assay. The antibodies did not react with enzyme samples obtained from rat hair follicles and bovine epidermis. The lack of immunoreactivity of the epidermal enzyme could not be accounted for by the species difference, since the antibodies reacted with a 83 kDa polypeptide of bovine brain, which was thought to represent a bovine counterpart of the muscle-type enzyme. The epidermal enzyme could be distinguished from the other enzyme samples by its high activity towards benzoylarginine. These data suggest the existence of the least three types of peptidylarginine deiminase in mammalian tissues, i.e., a muscle type, a hair follicle type, and an epidermal type.

Etude de l'action d'un traitement par voie topique sur la synthèse de la kératine pilaire chez le Rat

Synopsis Effect of topical treatment on pilar keratine synthesis in the rat The synthesis of keratin in pre-pubic Wistar rats has been studied under the influence of topic application of a lotion containing vegetable extracts. Changes of keratin synthesis in the rat was judged by the incorporation of a tagged precursor in the rat hair: cystein S-35 administered orally. Two protocols were followed each giving similar results. The first method concerned the regularity of hair growth with one sample taken per animal, and the second required multiple sampling in the same animal. Treatments with daily applications were in the range of 7-21 days. Results were analysed statistically in comparison with untreated zones. The excipient was tested separately in parallel. This rigorous procedure was essential, since the variations between individuals was wide in spite of the rats having been selected from the same litter. Daily application of the lotion showed an increase starting on the seventh day of the synthesis of keratin; the activity of the hair samples was already increased at this time by 90 to 400% (0.05>P>0.01). After 15 days increase reached > 1000% (P<0.05). Increase found for rats treated with the excipient do not reach significance. The hair growth cycle being 21 to 30 days, further continuation of the treatment gave only relatively weak stimulation of the keratin synthesis, the passage into the telogen phase slowing the synthesis of keratin whether it was produced from bulbar pre-keratin or synthesised in the hair itself.

Effects of prolonged duct ligation of the rat salivary glands on the activity of trypsin-like protease

The effects of ligation on body weight, protease activity and hair kynurenine content were observed. The body weights of parotid gland(PT)-ligated and of combined submandibular (SM)-, sublingual (SL)- and PT-ligated rats were much less than those of sham-operated controls. However, the weights of SM,SL-ligated rats were similar to those of controls. The activity of trypsin-like protease in the duct-ligated submandibular gland was significantly reduced to 0.3–0.7 per cent of that in controls. Protein concentration also decreased in the duct-ligated submandibular gland. Kynurenine content in the hair of duct-ligated rats was higher than that in controls.

Influences of protein malnutrition on amino acid composition, trace metal elements and tensile strength of rat hairs.

We examined hair properties from determinations of diameter, amino acid composition, trace metal elements, and tensile strength of the hairs from protein-malnourished rats. The coarse or medium hair diameters of the experimental protein-malnourished rats had a tendency to decrease more than those of the control. Total contents of amino acids in the hairs had a tendency to decrease in the protein-deficient rats. Cystine content of rat hairs definitely decreased only in 5% wheat- and 5% rice-pattern amino acid mixture diet groups but not in 5% gluten diet and 5% casein diet groups. And many of the low-protein diet groups were significantly lower in methionine content than the control except for the 5% casein diet group. The Mg, Zn, and Fe contents in the hairs considerably increased in protein-deficient rats against the control. Tensile strength of coarse hairs in the experimental protein-malnourished rats was significantly lower than that of the control. The changes in amino acid composition of rat hair proteins are more likely to be influenced by various qualities of dietary protein or different compositions of amino acid mixtures in the diets at a similar dietary protein level. It should seriously be considered from our data whether the reduced cystine content in the hair can be regarded as an indicator of nutritional status.

Extraction of Light Filth from Whole Leaves of Alfalfa, Lemon Balm, Papaya, and Spearmint: Collaborative Study

Results are reported for a collaborative study to extend AOAC method 44.A06-44.A08 to extraction of light filth from whole leaves of alfalfa, lemon balm, papaya, and spearmint. A 5 g (spearmint) or 10 g (alfalfa, lemon balm, papaya) test portion is defatted with isopropanol in a simple reflux apparatus. Rat hairs, insect fragments, and whole insects are isolated by wet sieving on a No. 230 sieve, a deaerating boil in 40% isopropanol, and flotation with mineral oil-heptane (85 + 15) from Tween 80-Na4EDTA (1 + 1) and 40% isopropanol in a Wildman trap flask. Each product was spiked at a different level. For rat hairs, recoveries averaged 82.2% from alfalfa, 88.9% from lemon balm, 80.6% from papaya, and 79.6% from spearmint. Recoveries of whole or equivalent insects from these products averaged 66.1, 218.8, 69.4, and 85.4%, respectively; recoveries of insect fragments from these products averaged 89.6, 94.4, 94.1, and 88.1%, respectively. The method has been adopted official first action for extraction of light filth from whole leaves of alfalfa, papaya, and spearmint. The extension of the method to lemon balm was not recommended because of interferences by intrinsic whole insects, which were the same species as the spike material.

Detection of cocaine in rats from analysis of hair.

The detection of benzoylecgonine in the hair of cocainetreated rats is studied with the use of RIA technique. The cocaine metabolite can be determined in whole hair of rats up to ten days after the last administration of the drug. Benzoylecgonine can be detected in the hair of cocaine-treated rats with the use of the radioimmunoassay technique after sample extraction. After a period of ten days, cocaine metabolites could be detected under the conditions described in the experimental procedure. The concentrations of benzoylecgonine ranged between 23,94 and 47,56 ng/g. The analysis of hair by means of a sensitive and specific method such as radioimmunoassay would be highly advantageous since hair samples are easily accessible, stable and retain the drug for long periods of time.

Deterioration of poultry farm environment by commensal rodents and their control

Poultry farms in India have been found to be heavily infested with the cosmopolitan house rat, Rattus rattus L. and occasionally with the house mouse, Mus musculus L. and the lesser bandicoot, Bandicota bengalensis (Gray). These rodents cause damage to eggs (average 5·25 1000 −1 eggs), egg trays, gunny bags, poultry feed and poultry house structures. Samples of the floor scracth showed 2·7% contaminated with rat hairs and 4·6% with pellets. Similarly, 3·3% of samples of poultry feed from godowns and 0·4% from feeders had signs of rodent contamination. In the poultry farms the rodents showed their maximum activity in feed gadowns. In the poultry houses, R. rattus were frequently found on the overhead structures. The results of trapping rodents with sliding-door cumulative catch-type traps showed a positive correlation between pre-treatment activity census and post-treatment percentage reduction. Success of trapping decreased with decreasing pre-treatment rodent activity. Data revealed that some trap-shy indivuduals persisted in the poultry farms. For poison baiting, specially designed bait boxes 33 × 23 × 23 cm each with three 10 cm long side tunnels 6-6·5 cm in diameter, have been found highly effective in attracting a large number of rodents to the baits. Baits prepared from cereal flour and fine grains like millet were found suitable to prevent any spillage. Poisoning of rodents with 2·4% zinc phosphide and 0·005% brodifacoum and bromadiolone baits resulted in an 80·8–97% reduction in census bait taken and 100% in track marking activity in the case of zinc phosphide. However, on two separate farms, 88·8 and 92·8% control success could be achieved with two treatments of brodifacoum at 15 day intervals and zinc phosphide at 54 day intervals respectively. In these cases, single treatments were insufficient. With zinc phosphide baiting, dead rats were found within 24 hours and their number varied from 1·4 to 5·4 bait container −1 day −1. With the anticoagulant poisons most of the rats died out of sight and a search was needed to avoid any unhygienic conditions due to their decomposing carcasses. Occasionally the chicks pecked at the hairs and skin of dead rats but this did not result in any secondary poisoning.

A growth-promoting factor existing on the body surface of rats

Effects of water-soluble matter adhering to rat hairs on fibroblasts were examined. The dialysate of the wash water of rat hairs significantly enhanced the cell proliferation of both diploid human dermal fibroblasts (DHDF) and diploid rat fibroblasts (DRDF). The cell growth-promoting activity was partially purified by a gel filtration column chromatography. The activity permeates through a ultrafiltration membrane (M.W. cut off: 500). Analyses of its chemical nature show that it is soluble in water, dimethyl sulfoxide or acetonitrile, insoluble in other organic solvents examined, stable to heat or pH shock, and resistant to a bacterial protease.

The effect of fluidized bed combustion residue on the composition and nutritional quality of food crops for hamsters and rats

Food crops (corn, oats, soybeans, vegetables) were grown on soils treated with fluidized bed combustion residue (FBCR) or hydrated lime. The composition of the foods and their nutritional quality were evaluated in growth, balance and carcass composition studies with growing hamsters and rats. Application of FBCR had little effect on elemental concentrations of dietary components. Weight gains in hamsters over a 6 week period were higher on FBCR than on lime-treated corn diets, but there were no differences due to FBCR in gains of hamsters on the oats diets or in rats on either of the cereal based diets. Apparent retention of nitrogen, calcium, phosphorus, sulphur and magnesium was determined by balance and by carcass analysis. Differences in mineral retention between FBCR and lime treatments were generally small and inconsistent. Analysis of the whole body of hamsters showed lower concentrations of nitrogen, phosphorus, zinc and copper with FBCR compared to lime-treated corn diets; little difference in body composition was found in the rat. There was no significant accumulation of heavy metals in liver, kidney, bone, serum or hair (of rats only) and no significant differences in concentrations of elements in organs due to application of FBCR to soils on which the dietary components had been grown.

The putative lead-binding carrier protein in rat epidermis using210Pb

To verify the usefulness of hair as an indicator of210Pb and109Cd accumulation in rats their distribution in different organs were determined. Whereas the radioactivity following210Pb i.p. administration after seven days is extremely diminished to compare with that after two days, a considerable accumulation with time of109Cd was observed under similar experimental conditions. The binding of lead in rat epidermis and hair was investigated and relatively tightly bound210Pb to extracted proteins was established. By electrophoretic analysis of epidermal proteins using PAGE-SDS binding of radiolead to a protein carrier with m.w. of about 16 000 was detected.

Extraction of Light Filth from Whole Peppermint Leaves: Collaborative Study

Results are reported for a collaborative study of a method for the extraction of light filth from whole peppermint leaves. A 5 g sample is defatted with isopropanol in a simple reflux appartus. Rat hairs, insect fragments, and whole insects are isolated by wet sieving on a No. 230 sieve, a deaerating boil in 40% isopropanol solution, flotation with Tween 80-Na4EDTA (1 + 1) and mineral oil-heptane (85 + 15), and trappings in a Wildman trap flask. Average recoveries obtained by 6 collaborators for 3 spike levels of rat hairs (5, 10, 15) were 83.3, 87.5, and 82.2%, respectively. For whole insects (5, 10, 15) recoveries averaged 85.0, 80.0 and 77.2% respectively; for insect fragments (20, 30, 50) recoveries averaged 79.6, 88.3, and 84.8%, respectively. The average recoveries for the 3 levels of each analyte were not significantly different. The method has been adopted official first action.

Effects of X-irradiation on rat hair follicles.

The alterations of normal growth of hair follicles following irradiation of rat tails with X-rays have been analysed. The changes in follicle length are attributed to a series of deleterious events occurring in the hair matrix after irradiation. A dose-dependent reduction of length was demonstrated for a given post-irradiation interval. An approximate exponential response was obtained for all conditions excepting low doses for which a marked reduction of follicle length was observed a short time after irradiation and was ascribed to the depletion of highly radiosensitive cells. At later post-irradiation times this response was obscured by the resumption of follicle growth.