Application of high-performance liquid chromatography to the study of esterified 7-dehydrocholesterol in rat skin

Takada, K; Takashima, Atsuko; Kobayashi, Tadashi; Shimoi, Yasuko

doi:10.1016/0005-2760(81)90288-5

Cited by 11 publications

(4 citation statements)

References 16 publications

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“…In line with Takada et al. (), high UVB doses lead to an increase in 7‐DHC in the skin. The explanation seems to be a decreased activity of the 7‐DHC‐reductase in keratinocytes induced by high vitD and 25‐OH‐D concentrations in serum (Zou and Porter, ) with the goal to provide all the 7‐DHC in skin for the vitD synthesis as a positive feedback regulation.…”

Section: Discussionsupporting

confidence: 87%

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Vitamin D metabolism in growing pigs: influence of UVB irradiation and dietary vitamin D supply on calcium homeostasis, its regulation and bone metabolism

Kolp

Wilkens

Pendl

et al. 2017

Animal Physiology Nutrition

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SummaryThe aim of this study was to prove whether pigs are able to synthesize vitamin D (vitD) in the skin and to investigate the influence of ultraviolet irradiation (UVB) on vitD status and calcium (Ca) homeostasis of growing pigs. Thirty-two 11-week-old pigs were kept without access to sunlight and divided into four groups receiving the following treatment in a 2 9 2 factorial design: (i) UVB irradiation or not and (ii) vitD in feed or not. Blood, urine and faeces were sampled every third week. In serum, vitD metabolites, Ca, phosphorus (P), magnesium (Mg) and bone markers were analysed. Digestibility of Ca, P and Mg as well as urinary excretion of these minerals was analysed. After 14 weeks, the animals were slaughtered, and samples of skin, intestines, kidneys and bones (metatarsus) were taken for further analyses: sterols of vitD synthesis in the skin, Ca flux rates in the intestines, expression of genes involved in Ca transport in the intestines and kidneys, bone mineral density (BMD) with the aid of peripheral quantitative computer tomography and bone mineral content by ashing the metatarsus. Irradiated animals showed higher levels of 7-dehydrocholesterol and tachysterol in the skin, higher levels of 25-hydroxycholecalciferol and 1,25-dihydroxycholecalciferol in the serum and higher Ca net flux rates were determined in Ussing chambers. In contrast, the expression of genes involved in Ca transport in the intestines and kidneys was not altered. Similarly, the digestibility of Ca and P as well as the urinary excretion was not affected. With respect to the metatarsus, no differences in mineral contents and BMD were found between groups. At the end of the study, some subclinical signs of beginning vitD 'insufficiency' were observed in the group without access to vitD (represented by higher expression of 1a-hydroxylase in the kidney and increased parathyroid hormone in serum).

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Section: Discussionsupporting

confidence: 87%

“…Although the used UVB dose in our study was lower compared to the dose used by Takada et al. (), it was enough to enhance the 7‐DHC content (in forehead) or at least prevent a decrease in the skin as a long term effect (other localizations).…”

Section: Discussionmentioning

confidence: 60%

Vitamin D metabolism in growing pigs: influence of UVB irradiation and dietary vitamin D supply on calcium homeostasis, its regulation and bone metabolism

Kolp

Wilkens

Pendl

et al. 2017

Animal Physiology Nutrition

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“…The average concentration of cutaneous 7‐DHC in the Hoffmann's two‐toed sloths in this study was 0.197 nmol/cm 2 . The levels measured in the sloths are hundreds‐fold to over a thousand‐fold lower than concentrations reported in humans, rats, and pigs (Kolp et al, 2017; MacLaughlin & Holick, 1985; Moody et al, 1990; Takada et al, 1981). Numerous studies have measured cutaneous 7‐DHC levels in animal species and have revealed that concentrations can vary widely between and within species, although in general, concentrations are much higher in species where it is known that cutaneous synthesis occurs, compared to species where it does not.…”

Section: Discussionmentioning

confidence: 73%

“…Conversely, exposure of skin to UVB light was shown to have no effect on 7‐DHC concentrations in rats, sheep, goats, and several carnivore species (Corbee et al, 2015; Kohler et al, 2013; Yasumura et al, 1977). Finally, numerous other studies have shown increased levels of skin 7‐DHC following exposure to UVB light, including in pigs, rats, sheep, and goats (Kolp et al, 2017; Nemeth et al, 2017; Takada, 1983; Takada et al, 1981). Further research would be needed to determine if the absence of UVB light exposure in this study had any impact on the levels of skin 7‐DHC in the sloths.…”

Section: Discussionmentioning

confidence: 94%

Cutaneous concentrations of 7‐dehydrocholesterol in Hoffmann's two‐toed sloths (Choloepus hoffmanni) in managed care

Jimenez

Makowski²,

Scanlon

et al. 2021

Zoo Biology

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Hoffmann's two‐toed sloths (Choloepus hoffmanni) are unique animals popular in zoological settings. The role of vitamin D in the maintenance of calcium homeostasis in this species is unexplored, although disorders of calcium homeostasis have been reported in managed sloths, including urolithiasis and soft tissue mineralization. This study assessed cutaneous concentrations of 7‐dehydrocholesterol (7‐DHC) in nine indoor‐housed Hoffmann's two‐toed sloths, as a means of evaluating the potential for cutaneous photobiosynthesis of vitamin D3. Samples were obtained from both abdominal and lumbar regions of the skin to assess for regional variation in 7‐DHC concentration. The average concentration of 7‐DHC in the sloth skin was low (0.197 ± 0.02 nmol/cm2). Location had a significant effect on 7‐DHC level only when concentrations were expressed based on the wet weight of the sample (ng/g), but levels were similar when values were normalized to biopsy surface area (nmol/cm2).

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HPLC analysis of desmosterol, 7‐dehydrocholesterol, and cholesterol

Goh

Colles

Otte

1989

Lipids

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A simple and sensitive method to analyze mixtures of desmosterol, 7-dehydrocholesterol and cholesterol is described. The method involves the oxidative conversion of the sterols with cholesterol oxidase, followed by high performance liquid chromatographic (HPLC) analysis. A C18 reversed phase column (3 microns, 75 X 4.6 mm) and a mixture of methanol and acetonitrile (1:1, v/v) at a rate of 1 ml/min are used to separate the sterols. The eluted sterols are quantified by measuring UV absorption at 240 nm. As little as 10 pmoles of sterol can be quantified under these conditions.

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Application of high-performance liquid chromatography to the study of esterified 7-dehydrocholesterol in rat skin

Cited by 11 publications

References 16 publications

Vitamin D metabolism in growing pigs: influence of UVB irradiation and dietary vitamin D supply on calcium homeostasis, its regulation and bone metabolism

Vitamin D metabolism in growing pigs: influence of UVB irradiation and dietary vitamin D supply on calcium homeostasis, its regulation and bone metabolism

Cutaneous concentrations of 7‐dehydrocholesterol in Hoffmann's two‐toed sloths (Choloepus hoffmanni) in managed care

HPLC analysis of desmosterol, 7‐dehydrocholesterol, and cholesterol

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