The liver also plays an important role in vitamin and mineral ( iron & copper ) storage. About 80% of the body's vitamin A stores are concentrated in fat droplets within the stellate cells of the liver. In pathological conditions like hepatic fibrosis or liver cirrhosis the stellate cells lose vitamin A, transform into fibroblasts or myofibroblasts and begin producing large amounts of collagen and adhesive glycoproteins. * Normal vitamin A reserves are enough to prevent a deficiency for about 10 months. The liver also contains about a year supply of B12. Vitamin D stores equal about 3-4 months. Small amounts of Vitamins E and K and Vitamin C are stored in the liver to facilitate liver functions.
Four L-type transporters (LAT1-4) have been identified, two of which (LAT1,2) belong to the heterodimeric amino acid transporter family. These transporters consist of a heavy chain and a light chain, linked through a disulfide bond (39). There are 2 possible heavy chains, SLC3A1 (rBAT) and SLC3A2 (4F2hc or CD98), and in humans there are 13 possible light chains belonging to the SLC7 gene family. The 4F2 or CD98 cell surface antigen is expressed in many tissues, especially on activated lymphocytes and tumor cells. 4F2hc is a glycosylated protein with a single transmembrane domain, whereas the light chains are not glycosylated and have 12 transmembrane domains (40). LAT1 and LAT2 consist of the SLC3A2 heavy chain in combination with the SLC7A5 and SLC7A8 light chain, respectively. They are obligate exchangers, implying that the cellular uptake of extracellular substrates is tightly coupled to the efflux of intracellular substrates.
Many attempts at using medications to impact appetite hormone regulation either haven't worked or produced unacceptable side effects. Pharmaceuticals that acted as ghrelin antagonists were developed as antiobesity drugs, but they failed to reduce food Similarly, giving someone extra PYY, which promotes satiety, can cause several gastrointestinal side effects, including Moreover, oral doses of PYY aren't absorbed well, and injections of PYY aren't as effective as what the body secretes Nonetheless, pharmaceutical companies are still working to develop successful appetite hormone-based treatments for