Dietary vitamin D dependence of cat and XXXX due to inadequate cutaneous synthesis of vitamin D.

@entity235 @entity35 @entity14952 @entity3875
As in herbivores and omnivores, the biosynthesis of @entity3875 in the skin exposed to ultraviolet (uv) light is generally expected to also occur in the @entity235 and the cat. The purpose of this in vitro study was to measure the concentrations of @entity3875 and its precursor @entity14952 ( @entity14952 ) in @entity235 and cat skin before and after a quantitatively and qualitatively standardized exposure to uv light. The results are compared to those obtained by the same method in the skin of the @entity35 . The efficiency of extracting @entity14952 and @entity3875 from skin was 72 +/- 8% and 67 +/- 3%, respectively. In @entity235 and cat skin the concentrations of nonesterified @entity14952 were below the detection limit of the HPLC system. Therefore, skin extracts were saponified and total @entity14952 and @entity3875 concentrations were measured by normal-phase HPLC. Before irradiation with uv-B light the total concentrations of @entity14952 were 1858 +/- 183, 1958 +/- 204, and 17,620 +/- 2345 ng/cm2 skin (mean +/- SEM; n = 5) for the @entity235 , the cat, and the @entity35 , respectively. The corresponding concentrations of @entity3875 were 211 +/- 44, 193 +/- 18, and 161 +/- 32 ng/cm2 skin for the @entity235 , the cat, and the @entity35 , respectively. Irradiation of standard solutions of @entity14952 with 0.15 J uv-B light/min resulted in a time-dependent decrease in @entity14952 and a concomitant increase in previtamin D3.(ABSTRACT TRUNCATED AT 250 WORDS)
