Precise Evaluation of Ultraviolet Therapy in Experimental Rickets

Bunker, John W. M.; Harris, Robert S.

doi:10.1056/nejm193701282160405

Cited by 18 publications

(4 citation statements)

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“…The relative power emitted from the lamp expressed in terms of the most effective wavelength, 295 nm, is 245.3 ,W/cm2, calculated from data of Kobayashi & Yasumura (1973). This value is based on the activity spectrum obtained in vivo; other activity spectra obtained in vivo have been reported: that of Bunker & Harris (1937) would give a value about 30% lower and that of Knudsen & Benford (1938) a value about 45% lower.…”

Section: Irradiationmentioning

confidence: 95%

Interrelationships in rats of tissue pools of cholecalciferol and 25-hydroxycholecalciferol formed in u.v. light

Lawson¹,

Sedrani²,

Douglas³

1986

Biochemical Journal

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Vitamin D-deficient rats were irradiated with u.v. light three times weekly for 30 min for several weeks. D3 (cholecalciferol) and 25(OH)D3 (25-hydroxycholecalciferol) concentrations in skin, plasma, muscle and adipose tissue were measured. In other experiments, isolated skin or the whole animal was irradiated once and the cholecalciferol response monitored. Only a small fraction of the 7-dehydrocholesterol in skin is converted into D3 (less than 2%), and the presence of fur decreases the proportion converted into 20% of that occurring in shaved rat skin. D3 formed in the skin disappears relatively slowly, so that about 90% has gone after 7 days. In normal rats 10 micrograms of D3 formed over 2 h irradiation only caused a small rise in plasma D3 concentration over the following week, indicative of a high rate of clearance from this tissue. Irradiation of vitamin D-deficient rats for a prolonged period raised plasma D3 and 25(OH)D3 concentrations to a constant value. D3, but not 25(OH)D3, could be found in adipose tissue and muscle. Prolonged irradiation of normal rats showed these tissues and plasma could hold very large amounts of D3. Pharmacokinetic analysis of the changes in D3 concentration in rats showed that the disposition kinetics of D3 was explained by a two-compartment model with half-lives of 13.8 and 7.7 days. The volume of distribution of the more-slowly-turning-over compartment was 500 ml, which presumably reflects the large amounts of D3 that can accumulate in adipose tissue. Rat skin can synthesize about 0.85 ng of D3/mJ of u.v. light energy, but it seems that not all this is available to the rat. Adipose-tissue D3 is available for use by the rat, the t1/2 being 12.0 days.

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Section: Irradiationmentioning

confidence: 95%

Interrelationships in rats of tissue pools of cholecalciferol and 25-hydroxycholecalciferol formed in u.v. light

Lawson¹,

Sedrani²,

Douglas³

1986

Biochemical Journal

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“…4 The MacLaughlin et al 12 action spectrum for the conversion of 7-dehydrocholesterol to previtamin D 3 in human skin (᭹) and the absorption spectrum of 7-dehydrocholesterol multiplied by the transmission through stratum corneum from an unexposed skin site ( ) and a skin site repeatedly exposed to UV-B ( ). 27 Although there is some debate about the quantity of 7-DHC in human epidermis and it is likely to vary between one individual and another, most estimates for people in middle age are in the range of approximately 1 mg cm -2 . 17, 30 The detection limit for previtamin D 3 by conventional HPLC was stated as 0.3% of the epidermal 7-DHC concentration, 31 i.e.…”

Section: The Maclaughlin Et Al Action Spectrummentioning

confidence: 99%

Is the action spectrum for the UV-induced production of previtamin D3 in human skin correct?

Norval

Björn

Gruijl

2010

Photochem Photobiol Sci

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The universally recognised action spectrum for the UV-induced conversion of 7-dehydrocholesterol to previtamin D(3) in human skin was published in 1982, and indicates a maximum at about 297 nm with essentially no production above 315 nm. This work represents a milestone in research on vitamin D, but limitations in the original data should be recognised. Various findings have arisen in recent years which cast doubts on the accuracy of the action spectrum and its application for spectral weighting in calculations of effective UV doses. In conclusion, the construction of an entirely new computational model to predict previtamin D levels is recommended.

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“…While UVR is thought to be the major determining factor in the synthesis of vitamin D, other factors may be important (Boyle, 1980). UVR has been used for the treatment of vitamin D deficiency and of skin disorders for many years (Bunker and Harris, 1937;van der Lugt and Rottier, 1958;Daniels, 1974). In parts of the Soviet Union, such as Siberia, so-called erythemal and sun-burn lamps are widely used in large industrial and instutional buildings including public schools (Zabaluyeva, 1958).…”

Section: Introductionmentioning

confidence: 99%