Comparison of receptors and enzymes regulating cholesterol levels in liver between SHR/NDmcr-cp rats and normotensive Wistar Kyoto rats at ten weeks of age.

The spontaneously hypertensive rat (SHR)/NDmcr-cp (SHR-cp), which is a metabolic syndrome model rat, was reported to show hypercholesteremia, as compared with lean littermates. The serum total cholesterol level in SHR-cp at 18 weeks of age is higher than that of normotensive Wistar Kyoto rat (WKY), but that in SHR-cp at 10 weeks of age is the same. The objective of this study is to clarify whether there are differences in the system regulating serum cholesterol levels between SHR-cp and WKY at 10 weeks of age.

Effect of δ-tocotrienol on melanin content and enzymes for melanin synthesis in mouse melanoma cells.

In the present study, we investigated the dose-dependent effect of delta-tocotrienol long term (48, 72 h) on the melanin content of cells treated with delta-tocotrienol, and whether cells treated with delta-tocotrienol for long a time show cytotoxicity. We also examined whether other enzymes responsible for melanin biosynthesis, tyrosinase-related protein-1 (TRP-1) and -2 (TRP-2), are involved in the decrease in melanin levels. Protein levels in cells treated with 25 or 50 microM delta-tocotrienol for 48 h or 72 h were similar to those in control cells.