Comparative effects of short-term and long-term insulin-induced hypoglycemia on glucose production in the perfused livers of weaned rats.
Journal Title: Pharmacological Reports - Year 2011, Vol 63, Issue 5
Abstract
The liver glucose production (LGP) levels of 15-h overnight fasted weaned rats submitted to short-term insulin-induced hypoglycemia (ST-IIH) and long-term IIH (LT-IIH) were compared. Experiments to characterize ST-IIH or LT-IIH that followed an intraperitoneal (ip) injection (1.0 U/kg) of regular (ST-IIH) or insulin detemir (LT-IIH) were performed and glycemia were measured 0 (normoglycemic control), 0.5 h (ST-IIH), 4 h and 6 h (LT-IIH) later. The values of glycemia (mg/dl) were 77.8 ±l 7.2 (normoglycemic control), 26.2 ±l 6.1 (ST IIH 0.5 h), 21.2 ±l 7.6 (LT-IIH 4 h) and 35.3 ±l 14.5 (LT-IIH 6.0). The LGP levels were measured in the rats submitted to ST-IIH (0.5 h) and LT-IIH (4 h or 6 h). The rats that received ip saline were used as the normoglycemic control group (COG). The livers from the COG and IIH groups (ST-IIH or LT-IIH) were perfused in situ with infusion of L-alanine (5 mM), L-glutamine (10 mM), glutamine dipeptide (5 mM), L-lactate (2 mM) or glycerol (2 mM). The ST-IIH rats showed a higher LGP level than COG group following the L-glutamine infusion (p < 0.05), but the LGP levels that were measured following the L-lactate, L-alanine, glutamine dipeptide (5 mM), L-lactate (2 mM) or glycerol infusion remained unchanged. Moreover, if the period of IIH was expanded to 4 h following insulin injection, the LGP levels induced by L-alanine, glutamine dipeptide or glycerol infusion also increased (p < 0.05, LT-IIH vs. COG). However, the LGP from the L-lactate infusion remained unchanged until 6 h after insulin injection. In conclusion, these results suggest that the intensification of liver gluconeogenesis during ST-IIH and LT-IIH in weaned rats is not a synchronous "all or nothing" process; instead, this process integrated in a temporal manner and is specific for each gluconeogenic substrate.
Authors and Affiliations
Romir Rodrigues, Kassia Feitosa, Antonio Felisberto-Junior, Helenton Barrena, Rui Curi, Roberto Bazotte
Keywords
Related Articles
- EP ID EP92294
- DOI -
- Views 102
- Downloads 0
Effects of ethanol treatment on the neurogenic and endothelium-dependent relaxation of corpus cavernosum smooth muscle in the mouse.
The relaxation of cavernous smooth muscle is critical for inducing and maintaining a penile erection. The neurogenic- and endothelium-dependent relaxation of corpus cavernosum smooth muscle and the degenerative effect of...
Interactions between neuroleptics and CYP2C6 in rat liver - in vitro and ex vivo study.
The aim of the present study was to investigate the influence of classic and atypical neuroleptics on the activity of rat CYP2C6 measured as a rate of warfarin 7-hydroxylation. The reaction was studied in control liver m...
Heme oxygenase/carbon monoxide-biliverdin pathway may be involved in the antinociceptive activity of etoricoxib, a selective COX-2 inhibitor.
The aim of this study was to assess the interaction between the heme oxygenase-1/ biliverdin/carbon monoxide (HO-1/BVD/CO) and cyclooxygenase-2 (COX-2) pathways in the writhing test. Mice were pretreated with 0.1, 1 or 1...
Physiology and pharmacological role of the blood-brain barrier.
The central nervous system (CNS) is a perfectly regulated environment with conditions far different from those in the rest of the organism. Even slight changes in this machinery affect its functioning. The blood-brain ba...
Chronic ethanol tolerance as a result of free-choice drinking in alcohol-preferring rats of the WHP line.
The development of tolerance to alcohol with chronic consumption is an important criterion for an animal model of alcoholism and may be an important component of the genetic predisposition to alcoholism. The aim of this...