Carotenoids tissue concentrations

The hydrophobicity of these compounds requires protein binding to move carotenoids through aqueous environments an emerging area of research includes the identification of carotenoid transport proteins that determine, in part, carotenoid tissue concentrations. As carotenoids are found throughout nature, various models can be studied for example, Chapter 24 describes carotenoid... 

The relationship between serum and tissue concentrations of lutein and zeaxanthin was recently studied by Johnson et al, (2000). Dietary intake of xanthophyll-rich vegetables (for example, spinach and com) resulted in significant increases in lutein concentration in serum, adipose tissue and buccal cells, and this correlated with changes in MP density. However, P-carotene and lycopene are normally the major carotenoids detected in buccal cells (Peng et al, 1994). 

Kaplan, L.A., Lau, J.M., and Stein, E.A., Carotenoid composition, concentrations, and relationship in various human organs, Clin. Physiol. Biochem., 8, 1, 1990. Parker, R.S., Carotenoids in human blood and tissues, J. Nutr, 119, 101, 1989. Clifford, M.N., Anthocyanins nature, occurrence, and dietary burden, J. Sci. Food Agric., 80, 1063, 2000. 

Johnson, E. J., Suier, P. M., Sahyoun, N., Ribaya-Mercado, J., and Russell, R. M. (1995). Relation between p-carotene intake and plasma and adipose tissue concentrations of carotenoids and retinoids. Am, f, Clin. Nutr. 62,598-603. 

Carotenoids have been primarily utilized for enhancing the visual appearance of poultry meat and eggs, and the flesh of salmonids. In general, a dose-dependent response has been noted, with greater tissue concentrations occurring at higher levels of supplementation. 

Second, on their correlation of diet and serum with adipose tissue concentrations of carotenoids, the a -trans lycopene (55), 9 cis lycopene (58), 5 cis lycopene (59), total cis lycopene (60) and one tram and total cis type mixtures (a mixture of tram + cis.) of lycopene (3) were the only carotenoid which could show consistently an inverse correlation with the percentage body fat in three adipose tissues of abdomen, buttocks and thigh. However, there also was generally an inverse correlation of adipose tissue carotenoid concentrations with the percentage body fat. 

Second, on the adipose tissue carotenoid concentrations, the intake of these carotenoids was significantly correlated with three adipose tissue concentrations of a-carotene (1), P-carotene (2), P-cryptoxanthin (5) and total cis lycopene (60). 

Third, on the a correlation of the serum carotenoid concentrations with the abdominal adipose tissue, among these carotenoids, serum concentrations of the abdomen versus serum was significantly correlated with the a-carotene (1) [Pearson s correlation coefficient (PCC) 0.518 P<0.05] concentrations in the abdominal adipose tissue (Table 5). 

SCHMITZ H H, POOR c L, WELLMAN R B and ERDMAN J w Jr (1991) Concentrations of selected carotenoids and vitamin A in human liver, kidney and lung tissue. J Nutr 121(10) 1613-21. 

YEUM K J, AHN S H, RUPP DE PAIVA S A, LEE-KIM Y C, KRINSKY N I, and RUSSELL R M (1998) Correlation between carotenoid concentration in serum and normal breast adipose tissue of women with benign tumour or breast cancer , JNutr 128 (11) 1920-26. 

The carotenoid pathway may also be regulated by feedback inhibition from the end products. Inhibition of lycopene cyclisation in leaves of tomato causes increase in the expression of Pds and Psy-1 (Giuliano et al, 1993 Corona et al, 1996). This hypothesis is supported by other studies using carotenoid biosynthesis inhibitors where treated photosynthetic tissues accumulated higher concentrations of carotenoids than untreated tissues (reviewed by Bramley, 1993). The mechanism of this regulation is unknown. A contrary view, however, comes from studies on the phytoene-accumulating immutans mutant of Arabidopsis, where there is no feedback inhibition of phytoene desaturase gene expression (Wetzel and Rodermel, 1998). 

Among 27 prospective and case-control studies, 16 reported inverse associations between some carotenoids and CVDs, taking plasma or serum concentration as carotenoid biomarkers (11 of 16 studies), dietary intake (5 of 16 studies), or adipose tissue level (1 of 16 studies). With regard to the findings from the studies based on CVD risk, only two of seven presented significant inverse associations of carotenoids, particularly lycopene and P-carotene, whereas five studies of nine showed inverse correlations between myocardial infarcts and lycopene and/or P-carotene the others presented no associations. ... 

Natural (3-carotene contains numerous carotenoids and essential nutrients that are not present in synthetic (3-carotene. Natural (3-carotene can be consumed in larger quantities because body tissues regulate its use. Natural sources generally contain one or two carotenoids in lower concentrations and thus may not be suitable for all applications. However Dunaliella contains a range of carotenoids with wider applications. 

FIGURE 6.13 Gray-scale microscopic RRI image of an excised palm tissue sample (a) and intensity plot (b) along a line running through the middle of the distribution. Results show large spatial variation of the concentration of carotenoids within the skin on a microscopic scale. 

As a side aspect, the HPLC-Raman correlation results allow us to calibrate the RRS instruments in terms of carotenoid concentration. According to the regression analysis, the cumulative skin carotenoid content c, measured in pg per g of skin tissue, is linked to the height of the C=C RRS skin carotenoid intensity, I, via c [pg/g]=4.3 x 10 5=/ [photon counts]. Integrating the RRS spectra with the instrument s data acquiring software therefore allows us to display skin carotenoid content directly in concentration units, i.e., in pg carotenoid content per g of tissue. 

Carotenoids are also present in animals, including humans, where they are selectively absorbed from diet (Furr and Clark 1997). Because of their hydrophobic nature, carotenoids are located either in the lipid bilayer portion of membranes or form complexes with specific proteins, usually associated with membranes. In animals and humans, dietary carotenoids are transported in blood plasma as complexes with lipoproteins (Krinsky et al. 1958, Tso 1981) and accumulate in various organs and tissues (Parker 1989, Kaplan et al. 1990, Tanumihardjo et al. 1990, Schmitz et al. 1991, Khachik et al. 1998, Hata et al. 2000). The highest concentration of carotenoids can be found in the eye retina of primates. In the retina of the human eye, where two dipolar carotenoids, lutein and zeaxan-thin, selectively accumulate from blood plasma, this concentration can reach as high as 0.1-1.0mM (Snodderly et al. 1984, Landrum et al. 1999). It has been shown that in the retina, carotenoids are associated with lipid bilayer membranes (Sommerburg et al. 1999, Rapp et al. 2000) although, some macular carotenoids may be connected to specific membrane-bound proteins (Bernstein et al. 1997, Bhosale et al. 2004). 

---