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Light regulates many developmental and physiological processes in a large number of organisms. The best-known light response in the fungus Mucor circinelloides is the biosynthesis of beta-carotene. Here, we show that M. circinelloides sporangiophores also respond to light, exhibiting a positive phototropism. Analysis of both responses to different light(More)
1,25D3 is critical for the maintenance of normal reproduction since reduced fertility is observed in male rats on a vitamin D-deficient diet. Vitamin D-deficient male rats have incomplete spermatogenesis and degenerative testicular changes. In the present study we have examined the ionic involvement and intracellular messengers of the stimulatory effect of(More)
The steroid hormone 1α,25(OH)(2)-vitamin D(3) (1,25D(3)) regulates gene transcription through a nuclear receptor (VDRnuc) and initiation of rapid cellular responses through a putative plasma membrane-associated receptor (VDRmem). It has been described that successful mating and fertility rates are significantly decreased in vitamin D deficient male rats and(More)
BACKGROUND The effect of in vivo treatment with ursolic acid (UA) on glycemia in hyperglycemic rats and its mechanism of action on muscle were studied. METHODS The UA effects on glycemia, glycogen, LDH, calcium and on insulin levels were evaluated after glucose tolerance curve. The β-cells were evaluated through the transmission electron microscopy. UA(More)
A series of chalcone derivatives from 3,4-methylenedioxybenzaldehyde and substituted acetophenones have been synthesized and investigated as antihyperglycemic agents in a glucose loaded animal model. Chalcones with biological activity were compared with lispro, regular insulin and tolbutamide effects on serum glucose levels. Compound 01, without substituent(More)
The Sertoli cells play an essential role in the maintenance and control of spermatogenesis. The ecto-nucleoside triphosphate diphosphohydrolase (E-NTPDase) and 5'-nucleotidase activities can modulate the extracellular adenine nucleotide levels, controlling nucleotide-mediated signaling events in Sertoli cells. Since thyroid hormones (TH) and adenine(More)
The importance of non-genomic signaling as a complementary route for cell regulation has recently become evident. This rapid mechanism is utilized not just by peptide hormones, but also by steroids and other lipid-related substances, resulting in amplification and fine-tuning of the signals. The Sertoli cell is the principal target for hormone action in the(More)
Aromatase transforms irreversibly androgens into estrogens and is present in the endoplasmic reticulum of various tissues including the mammalian testis. In rat all testicular cells except peritubular cells express aromatase. Indeed in adult rat germ cells (pachytene spermatocytes and round spermatids) we have demonstrated the presence of a functional(More)
The purpose of this study was to investigate the effect of T3 on amino acid accumulation and on the membrane potential of Sertoli cells of immature rat testes. Testes of pre-pubertal and pubertal rats were pre-incubated (30 min) in Krebs-Ringer bicarbonate buffer and incubated in the presence of [14C]methylaminoisobutyric acid with and without T3 for 15, 45(More)
The purpose of this review is to discuss the cellular and molecular mechanisms of action of flavonoids focusing on carbohydrate metabolism. The beneficial effects of flavonoids have been studied in relation to diabetes mellitus, either through their capacity to avoid glucose absorption or to improve glucose tolerance. Furthermore, flavonoids stimulate(More)