RESUMEN
The stimulatory guanine nucleotide binding protein Gs couples many cellular receptors to adenylate cyclase, and the Gsα subunit activates all 9 isoforms of the adenylate cyclase catalytic unit to produce the enzyme product cyclicAMP or cAMP. In prefrontal cortex and cerebellum of unipolar depressive suicides, Rasenick and colleagues have found increased concentrations of Gsα in membrane lipid microdomains (Donati et al., 2008), where the ensconced Gsα is less likely to activate adenylate cyclase by receptor and postreceptor pathways (Allen et al., 2005, 2009). We report that a group of 7 depressed patients (DP-1) had (1) reduced activation of platelet receptor-stimulated adenylate cyclase by both prostaglandins E2 and D2 compared to controls, and (2) reduced postreceptor stimulation of adenylate cyclase by aluminum fluoride ion in both platelets and mononuclear leukocytes when compared to both another group of depressed patients (DP-2, n = 17) and to controls (n = 21). Our observations in the blood cells of the group DP-1 support the findings of Donati et al. (2008), and they reflect the importance of this interaction between the activated Gsα subunit and membrane lipid microdomains in the pathophysiology and treatment of some major depressive disorders.
Asunto(s)
Adenilil Ciclasas/metabolismo , Células Sanguíneas/metabolismo , Trastorno Depresivo Mayor/sangre , Subunidades alfa de la Proteína de Unión al GTP Gs/metabolismo , Microdominios de Membrana/metabolismo , Prostaglandinas/metabolismo , Adulto , Compuestos de Aluminio/metabolismo , Plaquetas/metabolismo , Dinoprostona/metabolismo , Femenino , Fluoruros/metabolismo , Humanos , Linfocitos/metabolismo , Masculino , Persona de Mediana Edad , Prostaglandina D2/metabolismoRESUMEN
In the United States, commercially available foods, including cocoa and chocolate, are being marketed with statements referring to the level of antioxidant activity and polyphenols. For cocoa-containing foods, there has been no comprehensive survey of the content of these and other chemistries. A survey of cocoa and chocolate-containing products marketed in the United States was conducted to determine antioxidant activity and polyphenol and procyanidin contents. Commercially available samples consisted of the top market share products in each of the following six categories: natural cocoa, unsweetened baking chocolate, dark chocolate, semisweet baking chips, milk chocolate, and chocolate syrup. Composite samples were characterized using four different methods: oxygen radical absorbance capacity (ORAC), vitamin C equivalence antioxidant capacity (VCEAC), total polyphenols, and procyanidins. All composite lots were further characterized for percent nonfat cocoa solids (NFCS) and percent fat. Natural cocoas had the highest levels of antioxidant activities, total polyphenols, and procyanidins followed by baking chocolates, dark chocolates and baking chips, and finally milk chocolate and syrups. The results showed a strong linear correlation between NFCS and ORAC (R (2) = 0.9849), total polyphenols (R (2) = 0.9793), and procyanidins (R (2) = 0.946), respectively. On the basis of principal component analysis, 81.4% of the sample set was associated with NFCS, antioxidant activity, total polyphenols, and procyanidins. The results indicated that, regardless of the product category, NFCS were the primary factor contributing to the level of cocoa antioxidants in the products tested. Results further suggested that differences in cocoa bean blends and processing, with the possible exception of Dutching, are minor factors in determining the level of antioxidants in commercially available cocoa-containing products in the United States.