Effects of stanniocalcin hormones on rat hepatic glucose homeostasis under fed and fasted conditions.

To test the hypothesis of conservation of stanniocalcin 1 and 2 (STC-1; STC-2) metabolic functions in vertebrates, we performed an in vitro study to determine if these hormones are implicated in regulation of the gluconeogenesis pathway, glycogen synthesis, and C-glucose conversion to CO in livers from fed and fasting rats (Rattus norvegicus). Stc1 and Stc2 gene expressions increased in the liver after fasting. STC-1 participated in the regulation of the hepatic gluconeogenesis pathway in rats when the precursor was C-lactate.

Effects of stanniocalcin 1 hormone on lactate metabolism in rat kidney under fed and fasted conditions.

To test the hypothesis of STC-1 participation in maintenance of glucose homeostasis in fed and fasting (48 h) rats, we investigated that this hormone may be implicated in the regulation of renal gluconeogenesis pathway from lactate and lactate oxidation in renal cortex and medulla. Our results demonstrate the hSTC-1 role on lactate metabolism in the renal cortex and medulla from fed and fasting rats. hSTC-1 increased the gluconeogenesis activity in fed state in renal cortex, and this increase was induced by raise in Pck1 gene expression.

Diet composition and long-term starvation do not affect crustacean hyperglycemic hormone (CHH) transcription in the burrowing crab Neohelice granulata (Dana, 1851).

The burrowing crab Neohelice granulata is a key omnivorous species in intertidal areas along the southwestern Atlantic from southern Brazil to northern Argentinean Patagonia. This crab is adapted to starvation and can endure natural periods of food deprivation. The metabolic adjustments during starvation depend on the type of diet the crabs were fed previously.

Metabolic effects of epinephrine on the crab Neohelice granulata.

Although widely known for their involvement in the control of carbohydrate and lipid metabolism of vertebrates, the participation of catecholamines (CAs) in the metabolism of invertebrates is less understood. This study was designed to identify the physiological role of Epinephrine (E) in the intermediary metabolism of the burrowing crab Neohelice granulata and how E regulates the metabolism in crabs fed with a high-carbohydrate (HC) or a high-protein (HP) diet. To answer these questions, we evaluated in vivo the effects of E injections on glucose and triglycerides in the hemolymph and tissue glycogen levels of crabs fed with HC or HP diet.

Insulin-like receptors and carbohydrate metabolism in gills of the euryhaline crab Neohelice granulata: Effects of osmotic stress.

The present study determined the effect of osmotic stress on the insulin-like receptor binding characteristics and on glucose metabolism in the anterior (AG) and posterior (PG) gills of the crab Neohelice granulata. Bovine insulin increased the capacity of the PG cell membrane to phosphorylate exogenous substrate poly (Glu:Tyr 4:1) and the glucose uptake in the control crab group. The crabs were submitted to three periods of hyperosmotic (HR) and hyposmotic (HO) stress, for 24, 72 and 144 h, to investigate the insulin-like receptor phosphorylation capacity of gills.

Serotonin effects in the crab Neohelice granulata: Possible involvement of two types of receptors in peripheral tissues.

In crustaceans, serotonin (5-HT) controls various physiological processes, such as hormonal secretion, color changes, reproduction, and metabolism. Since 5-HT injections cause hyperglycemia, this study was designed to further investigate this action of 5-HT in the crab Neohelice granulate, fed with a high-carbohydrate (HC) or a high-protein (HP) diet. The effects of pre-treatment with mammalian 5-HT receptor antagonists, cyproheptadine and methiothepin, were also investigated.

Visceral adiposity influences glucose and glycogen metabolism in control and hyperlipidic-fed animals.

Introduction: Evidences suggest that fat intake, visceral obesity and intracellular lipids are related to insulin impairment.

Objective: The objective of the present paper was correlate visceral obesity and metabolic alterations in control (CTR) and hyperlipidic cafeteria diet (CFT) fed animals.

Methods: After 6 months of diet treatment, liver and muscle of the male rats were utilized to determined glucose uptake and glycogen metabolism after administration of 0.

Metabolic effects of perinatal asphyxia in the rat cerebral cortex.

We reported previously that intrauterine asphyxia acutely affects the rat hippocampus. For this reason, the early effects of this injury were studied in the cerebral cortex, immediately after hysterectomy (acute condition) or following a recovery period at normoxia (recovery condition). Lactacidemia and glycemia were determined, as well as glycogen levels in the muscle, liver and cortex.

Effect of starvation and refeeding on amino acid metabolism in muscle of crab Neohelice granulata previously fed protein- or carbohydrate-rich diets.

The present study assesses the effects of starvation and refeeding on 1-[(14)C]-methyl aminoisobutyric acid ((14)C-MeAIB) uptake, (14)C-total lipids, (14)CO(2) production from (14)C-glycine, (14)C-protein synthesis from (14)C-leucine and Na(+)-K(+)-ATPase activity in jaw muscle of Neohelice granulata previously maintained on a carbohydrate-rich (HC) or high-protein (HP) diet. In N. granulata the metabolic adjustments during starvation and refeeding use different pathways according to the composition of the diet previously offered to the crabs.

Estrus cycle effect on muscle tyrosine kinase activity in bitches.

Estrus cycle is a well recognized cause of insulin resistance in bitches. The insulin receptor (IR) as well as the insulin-like growth factor-I receptor belong to the same subfamily of tyrosine kinase (TK) receptors. The objective of this study was to evaluate basal TK activity in muscle tissue of bitches during the estrus cycle.

Control of carbohydrate metabolism in an anoxia-tolerant nervous system.

Anoxia-tolerant animal models are crucial to understand protective mechanisms during low oxygen excursions. As glycogen is the main fermentable fuel supporting energy production during oxygen tension reduction, understanding glycogen metabolism can provide important insights about processes involved in anoxia survival. In this report we studied carbohydrate metabolism regulation in the central nervous system (CNS) of an anoxia-tolerant land snail during experimental anoxia exposure and subsequent reoxygenation.

Seasonal variation in glucose and neutral amino acid uptake in the estuarine crab Neohelice granulata.

This study investigates the mechanisms of glucose and amino acid transport in gills and jaw muscle of N. granulata collected from an estuarine natural population. The physicochemical parameters of the estuarine environment and of this crustacean's hemolymph were measured during different seasons of the year.

Lactate metabolism in the muscle of the crab Chasmagnathus granulatus during hypoxia and post-hypoxia recovery.

The present study showed that the lactate/glucose ratio in the hemolymph of Chasmagnathus granulatus maintained in normoxia (controls) was 4.9, suggesting that lactate is an important substrate for this crab. Periods of hypoxia are part of the biological cycle of this crab, and lactate is the main end product of anaerobiosis in this crab.