The possible influence of photoperiodism on carbohydrate metabolism has been evaluated in the feral pigeons. Both Dexamethasone (DXM) and Corticosterone (CORT) treated pigeons were exposed to NDL or LD 18:6 photoperiodic schedules and their tissue glycogen contents, blood glucose and hepatic phosphorylase and G-6-P’ase activity assayed. Both DXM & Corticosterone treatment increased tissue glyco...

Allosteric enzymes have very complex kinetic behaviours which are primarily interpreted through simplified models. To describe the functional properties of liver and muscle glycogen phosphorylase isozymes we have developed an experimental strategy based on the measurements of initial reaction rates in the presence of different concentrations of the effectors glucose-1-phosphate and methyl-xanth...

The effect of inhibition of glycogen phosphorylase by 1,4-dideoxy-1,4-imino-d-arabinitol on rates of gluconeogenesis, gluconeogenic deposition into glycogen, and glycogen recycling was investigated in primary cultured hepatocytes, in perfused rat liver, and in fed or fasted rats in vivo clamped at high physiological levels of plasma lactate. 1,4-Dideoxy-1,4-imino-d-arabinitol did not alter the ...

The milkfish, Chanos chanos , is an important aquaculture species that can be cultured in freshwater (FW) and seawater (SW) ponds because of its high euryhalinity. In winter, cold snap leading to mortality this tropical a critical issue for the industry Taiwan. Under hypothermal stress, however, changes energy supply osmoregulation euryhaline intriguing. study, we used antibody against glycogen...

The effect of estradiol on glycogen synthesis was examined in a primary cell culture system of the human endometrium. Estradiol inhibited glycogen synthesis in a dose dependent manner with a minimum effective dose of 10(-9)M. Progesterone-induced glycogen synthesis was completely abolished by the simultaneous addition of estradiol. Estradiol did not affect the activity of glycogen phosphorylase...

Timely, and sometimes rapid, metabolic adaptation to changes in food supply is critical for survival as an organism moves from the fasted to the fed state, and vice versa. These transitions necessitate major metabolic changes to maintain energy homeostasis as the source of blood glucose moves away from ingested carbohydrates, through hepatic glycogen stores, towards gluconeogenesis. The integra...

Lafora disease is an autosomal recessive form of progressive myoclonus epilepsy with no effective therapy. Although the outcome is always unfavorable, onset of symptoms and progression of the disease may vary. We aimed to identify modifier genes that may contribute to the clinical course of Lafora disease patients with EPM2A or EPM2B mutations. We established a list of 43 genes coding for prote...

In the liver, insulin suppresses hepatic gluconeogenesis by activating Akt, which inactivates the key gluconeogenic transcription factor FoxO1 (Forkhead Box O1). Recent studies have implicated hyperactivity of the Akt phosphatase Protein Phosphatase 2A (PP2A) and impaired Akt signaling as a molecular defect underlying insulin resistance. We therefore hypothesized that PP2A inhibition would enha...