Responsiveness of glycogen breakdown to cyclic AMP in perfused liver from rats with insulin-induced hypoglycemia

Vardanega-Peicher, M.; Curi, Rui; Silva, S. Pagliarini e; Nascimento, Katia Fialho do; Bazotte, Roberto Barbosa

doi:10.1590/s0100-879x2003000100007

Cited by 7 publications

(5 citation statements)

References 16 publications

(17 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…After laparotomy, livers were perfused in situ without recirculation with Krebs-Henseleit buffer containing lactate (2 mM), pH 7.4, saturated with an O 2 /CO 2 mixture (95/5%) pumped through a temperature regulated (37°C) membrane oxygenator prior to entering the liver via a cannula inserted into the portal vein ( 12 , 13 ). The whole procedure took about 10 min and the results obtained from these experiments reflect the in vivo condition immediately before the anesthesia, as previously described ( 3 , 10 , 12 – 14 ).…”

Section: Methodsmentioning

confidence: 99%

Performance during a strenuous swimming session is associated with high blood lactate: pyruvate ratio and hypoglycemia in fasted rats

Travassos

Godoy

Souza

et al. 2018

Braz J Med Biol Res

Self Cite

View full text Add to dashboard Cite

The aim of this study was to investigate the effect of lactatemia elevation and glycemia reduction on strenuous swimming performance in fasted rats. Three rats were placed in a swimming tank at the same time. The first rat was removed immediately (control group) and the remaining ones were submitted to a strenuous swimming session. After the second rat was exhausted (Exh group), the third one was immediately removed from the water (Exe group). According to the period of time required for exhaustion, the rats were divided into four groups: low performance (3–7 min), low-intermediary performance (8–12 min), high-intermediary performance (13–17 min), and high performance (18–22 min). All rats were removed from the swimming tanks and immediately killed by decapitation for blood collection or anesthetized for liver perfusion experiments. Blood glucose, lactate, and pyruvate concentrations, blood lactate/pyruvate ratio, and liver lactate uptake and its conversion to glucose were evaluated. Exhaustion in low and low-intermediary performance were better associated with higher lactate/pyruvate ratio. On the other hand, exhaustion in high-intermediary and high performance was better associated with hypoglycemia. Lactate uptake and glucose production from lactate in livers from the Exe and Exh groups were maintained. We concluded that there is a time sequence in the participation of lactate/pyruvate ratio and hypoglycemia in performance during an acute strenuous swimming section in fasted rats. The liver had an important participation in preventing hyperlactatemia and hypoglycemia during swimming through lactate uptake and its conversion to glucose.

show abstract

Section: Methodsmentioning

confidence: 99%

Performance during a strenuous swimming session is associated with high blood lactate: pyruvate ratio and hypoglycemia in fasted rats

Travassos

Godoy

Souza

et al. 2018

Braz J Med Biol Res

Self Cite

View full text Add to dashboard Cite

show abstract

“…The means of the AUCs of lactate and pyruvate in the adrenaline-stimulated perfusion were used to calculate the rates of glycolysis (= pyruvate + lactate) and glycogenolysis [= glucose + 1/2 (pyruvate + lactate)] of the groups [23]. …”

Section: Methodsmentioning

confidence: 99%

Sustained Liver Glucose Release in Response to Adrenaline Can Improve Hypoglycaemic Episodes in Rats under Food Restriction Subjected to Acute Exercise

Babata

Pedrosa

Garcia

et al. 2014

International Journal of Endocrinology

View full text Add to dashboard Cite

Background. As the liver is important for blood glucose regulation, this study aimed at relating liver glucose release stimulated by glucagon and adrenaline to in vivo episodes of hypoglycaemia. Methods. The blood glucose profile during an episode of insulin-induced hypoglycaemia in exercised and nonexercised male Wistar control (GC) and food-restricted (GR, 50%) rats and liver glucose release stimulated by glucagon and adrenaline were investigated. Results. In the GR, the hypoglycaemic episodes showed severe decreases in blood glucose, persistent hypoglycaemia, and less complete glycaemic recovery. An exercise session prior to the episode of hypoglycaemia raised the basal blood glucose, reduced the magnitude of the hypoglycaemia, and improved the recovery of blood glucose. In fed animals of both groups, liver glucose release was activated by glucagon and adrenaline. In fasted GR rats, liver glycogenolysis activated by glucagon was impaired, despite a significant basal glycogenolysis, while an adrenaline-stimulated liver glucose release was recorded. Conclusions. The lack of liver response to glucagon in the GR rats could be partially responsible for the more severe episodes of hypoglycaemia observed in vivo in nonexercised animals. The preserved liver response to adrenaline can partially account for the less severe hypoglycaemia in the food-restricted animals after acute exercise.

show abstract

“…An insignificant change in glycogenolysis during IIH suggests the possibility that the higher release of counteregulatory hormones (Davis et al, 1995;DeGalan et al, 2006) during IIH could not overcome the inhibitory effect of insulin on glycogenolysis (Vardanega-Peicher et al, 2003).…”

Section: Discussionmentioning

confidence: 99%

“…Thus, by using fed rats that are in a condition in which liver glycogen is not depleted, it was possible to demonstrate that glycogen (Lopes et al, 1998;Vardanega-Peicher et al, 2003), glycogen phosphorylase (Lopes et al, 1998) and glycogen synthase (VardanegaPeicher et al, 2000) were not activated in the defense against IIH.…”

Section: Introductionmentioning

confidence: 99%

Contribution of hepatic glycogenolysis and gluconeogenesis in the defense against short-term insulin induced hypoglycemia in rats

et al. 2008

View full text Add to dashboard Cite

Responsiveness of glycogen breakdown to cyclic AMP in perfused liver from rats with insulin-induced hypoglycemia

Cited by 7 publications

References 16 publications

Performance during a strenuous swimming session is associated with high blood lactate: pyruvate ratio and hypoglycemia in fasted rats

Performance during a strenuous swimming session is associated with high blood lactate: pyruvate ratio and hypoglycemia in fasted rats

Sustained Liver Glucose Release in Response to Adrenaline Can Improve Hypoglycaemic Episodes in Rats under Food Restriction Subjected to Acute Exercise

Contribution of hepatic glycogenolysis and gluconeogenesis in the defense against short-term insulin induced hypoglycemia in rats

Contact Info

Product

Resources

About