Antonio Díaz-Cruz

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Inosine, an endogenous nucleoside, has recently been shown to exert potent effects on the immune, neural, and cardiovascular systems. This work addresses modulation of intermediary metabolism by inosine through adenosine receptors (ARs) in isolated rat hepatocytes. We conducted an in silico search in the GenBank and complete genomic sequence databases for(More)
In isolated rat hepatocytes adenosine and inosine showed a dose-dependent increase in the rate of glucose synthesis from lactate with a Ka of 7.5 x 10(-8) and 9 x 10(-8) M, respectively. Absence of this action was recorded with: IMP, xanthosine, adenine, hypoxanthine, and uric acid. A reciprocal inhibition of individual gluconeogenic stimulation was found(More)
We have examined the effects of alpha 1- and beta-receptor activation on cyclic AMP (cAMP) accumulation in cultured pinealocytes from female ovariectomized rats, and from intact rats at proestrus treated with the antiestrogen Tamoxifen, the antiprogestagen RU486, or with both. Isoproterenol (a beta-agonist) significantly increased cAMP levels in(More)
The objective of this work is to identify the adenosine receptor subtype and the triggered events involved in the regulation of hepatic glycogen metabolism. Glycogenolysis, gluconeogenesis, cAMP, and cytosolic Ca2+ ([Ca2+](cyt)) were measured in isolated hepatocytes challenged with adenosine A1, A2A, and A3 receptor-selective agonists. Stimulation of(More)
Isolated rat hepatocytes, incubated in a high K+ medium which depolarizes their plasma membrane, were used to investigate the response to adenosine. High K+ concentration blocked both the adenosine mediated increase of calcium influx and the increase in the rate of urea synthesis. It is concluded that a) adenosine stimulates calcium influx in hepatocytes(More)
OBJECTIVE To assess effects of high dietary amounts of vitamin C or vitamin E and oxidative stress on the heart and growth performance of broilers maintained at an altitude of 2,200 m above sea level. ANIMALS 360 chicks (1-day-old broilers). PROCEDURE Birds were randomly assigned to 3 groups (120 chicks/group). Each group of birds was fed a specific(More)
It is known that adrenaline promotes hydroxyl radical generation in isolated rat hepatocytes. The aim of this work was to investigate a potential role of NADPH oxidase (Nox) isoforms for an oxidative stress signal in response to adrenaline in hepatocytes. Enriched plasma membranes from isolated rat liver cells were prepared for this purpose. These membranes(More)
The objective of this study was to evaluate the gluconeogenic response of in vitro stimulated hepatocytes from control broilers and broilers with clinical manifestations of the ascites syndrome. The basal rate of glucose synthesis from lactate was found to be threefold greater in sick birds than in the control group and stimulation obtained with epinephrine(More)
In rat hepatocytes, the role of cAMP and Ca(2+) as secondary messengers in the ureagenic response to stimulation of specific adenosine receptor subtypes was explored. Analyzed receptor subtypes were: A(1), A(2A), A(2B) and A(3). Each receptor subtype was stimulated with a specific agonist while blocking all other receptor subtypes with a battery of specific(More)
The effect of three different receptor-specific adenosine agonists on the rate of ureagenesis by isolated rat hepatocytes and the dependence on the external free Ca2+ concentration ([Ca2+]e) were investigated. In the presence of high [Ca2+]e all adenosine receptor agonists increased ureagenesis to similar levels. However, with low [Ca2+]e the effects of(More)