Retina human, pigments

A different approach led to the discovery of a bovine Y2 cDNA clone (Ammar et al., 1995). A retina and pigment epithelium cDNA library was screened for heptahe-lix receptors and a clone was identified whose human genomic homologue upon expression was found to find NPY with nanomolar affinity and displayed the characteristic Y2 pharmacological profile (Ammar et al., 1995). 

Bernstein PS, Yoshida MD, Katz NB, McClane RW, and Gellermann W (1998), Raman detection of macular carotenoid pigments in intact human retina, Invest. Ophthal. Vis. Sci. 39 2003-2011. 

Ermakov IV, McClane RW, Gellermann W, and Bernstein PS (2001b), Resonant Raman detection of macular pigment levels in the living human retina, Opt. Lett. 26 202-204. 

Gellermann W, Ermakov IV, Ermakova MR, McClane RW, Zhao DY, and Bernstein PS (2002a), In vivo resonant Raman measurement of macular carotenoid pigments in the young and the aging human retina, J. Opt. Soc. Am. A 19 1172-1186. 

Lutein and zeaxanthin are the dominant carotenoids in nonretinal eye tissue, and lycopene and p-carotene have been found in the ciliary body, which after the retina and the retinal pigment epithelium (RPE) contains the highest quantity of carotenoids (Bernstein et al. 2001). The orbital adipose tissue also contains measurable quantities of lutein and p-carotene, and possibly other carotenoids as minor constituents (Sires et al. 2001). It is also interesting to note that lutein was recently identified in the vitreous body of human fetuses, 15-28 weeks old (Yakovleva et al. 2007). However, these results may have to be considered with caution, because the vitreous bodies were described as substantially being penetrated with hyaloid blood vessels, which could have contaminated the vitreous with blood. 

Anderson, DH, Ozaki, S, Nealon, M, Neitz, J, Mullins, RF, Hageman, GS, and Johnson, LV, 2001. Local cellular sources of apolipoprotein E in the human retina and retinal pigmented epithelium implications for the process of drusen formation. Am J Ophthalmol 131, 767-781. 

Bone, RA and Landrum, JT, 1992. Distribution of macular pigment components, zeaxanthin and lutein, in human retina. Methods Enzymol 213, 360-366. 

Crane, U, Wallace, CA, McKillop-Smith, S, and Forrester, JV, 2000b. CXCR4 receptor expression on human retinal pigment epithelial cells from the blood-retina barrier leads to chemokine secretion and migration in response to stromal cell-derived factor 1 alpha. J Immunol 165,4372-4378. 

In photoreceptor cells, the rods and cones of the human retina, the retinal is linked to a specific protein termed opsin. The resulting pigment is known as rhodopsin. When a photon of light of the proper wavelength hits a molecule of rhodopsin, two chemical events take place. First, the ll-c -retinal is converted to the all-trans form and, secondly, the all-trani-retinal is released from the rhodopsin ... 

Detection of Macular Pigments in the Living Human Retina... 

Fig. 12.10. Raman spectra of excised human eyecup, obtained from tissue locations in the central fovea (trace a), the parafovea (trace b), and the peripheral macula trace c). Macular pigment carotenoid peaks are obtained at 1159 and 1524 cm 1 with good signal-to-noise ratio, and decreasing strengths (factor of 30) when the excitation beam is moved from the center of the macula trace a) toward the peripheral retina trace c)...

Brown PK and Wald G 1964 Visual pigments in single rods and cones of the human retina. Science 144, 45-52. 

Value is the response of the human brain to the quantity of a certain wavelength reaching the retina. When a black pigment is added to a hue, some of the light that was reflected from the hue is absorbed. The hue appears darker. When a white pigment is added to a hue, more light is reflected from the hue and it appears lighter. 

Figure 2.9 (a) Light-responsive rod cell from the human retina. The photoresponsive pigment rhodopsin... 

Gellermann, W., Ermakov, I.V., and McClane, R.W. Raman imaging of carotenoid pigments in human retina, Proc. SPIE, 4611,197-207, 2002. 

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