GLUT3 glucose transporter isoform in rat testis: localization, effect of diabetes mellitus, and comparison to human testis

1994 ◽  
Vol 267 (6) ◽  
pp. R1488-R1495 ◽  
Author(s):  
C. F. Burant ◽  
N. O. Davidson
Keyword(s):  
Diabetes Mellitus ◽  
Glucose Transporter ◽  
Insulin Treatment ◽  
Diabetic Rats ◽  
Human Testis ◽  
Hexose Transporter ◽  
Rat Testis ◽  
Protein Levels ◽  
Efficient Uptake ◽  
Transporter Expression

Facilitative hexose transporter expression was compared in rat and human testes. In rat testis, only GLUT1 and GLUT3 proteins were expressed. By contrast, human testis expressed GLUT1 and GLUT3 in addition to GLUT5. Immunocytochemical studies showed that GLUT3 was expressed in all cells of the seminiferous epithelium of rat testis, including sperm. In human testis, GLUT3 was expressed exclusively in cells juxtaposed to the lumen of the seminiferous tubule and ejaculate sperm, a pattern of expression that was identical to that of GLUT5. Induction of insulinopenic diabetes mellitus in the rat did not alter the levels or the distribution of GLUT3 protein or mRNA in the testis. Moreover insulin treatment of the diabetic rats did not produce changes in GLUT3 mRNA or protein levels. The results show that rat and human testis express the high-affinity glucose transporter GLUT3, which allows for the efficient uptake of glucose. In addition, the testis may be protected from changes in glucose transporter expression in experimental diabetes.

Hexose transporter expression in rat small intestine: effect of diet on diurnal variations

1996 ◽  
Vol 271 (1) ◽  
pp. G211-G216 ◽  
Author(s):  
C. P. Corpe ◽  
C. F. Burant
Keyword(s):  
Daily Variation ◽  
Control Diet ◽  
Diurnal Variations ◽  
Mrna Levels ◽  
Hexose Transporter ◽  
Diurnal Pattern ◽  
Protein Levels ◽  
Feeding Study ◽  
Hexose Transporters ◽  
Transporter Expression

In rodents, a number of intestinal digestive and absorptive processes demonstrate a diurnal pattern of activity. To investigate if the jejunal hexose transporters are regulated in such a diurnal fashion, the levels for the glucose and fructose transporter mRNA and proteins were determined at 6-h intervals over a 24-h control fed period. SGLT-1, GLUT-2, and GLUT-5 mRNA levels increased between two- and eightfold before the onset of peak feeding. GLUT-5 protein levels also varied in a diurnal fashion but were out of phase with the observed changes in GLUT-5 mRNA levels. In contrast, GLUT-2 protein levels remained relatively constant during the control fed 24-h period. The effect of dietary manipulations on the observed diurnal variation was also investigated. After only 3 h of feeding a 60% fructose-enriched diet, the levels of GLUT-5 mRNA and protein were significantly elevated. GLUT-5 mRNA and protein levels remained elevated relative to the level of control diet-fed animals over the ensuing 24 h and during the 7th day of fructose feeding. Exposure to elevated levels of fructose had no significant effect on the diurnal pattern of GLUT-2 and SGLT-1 mRNA. In contrast, GLUT-2 protein was rapidly downregulated during the length of the fructose feeding study. In conclusion, the data demonstrate a normal daily variation in the level of hexose transporter expression that can be rapidly modulated by diet.

Insulin treatment prevents vascular dysfunction in early juvenile alloxan-induced diabetes mellitus

1984 ◽  
Vol 247 (1) ◽  
pp. H132-H138
Author(s):  
S. M. Mueller
Keyword(s):  
Diabetes Mellitus ◽  
Insulin Treatment ◽  
Vascular Dysfunction ◽  
Treated Group ◽  
Diabetic Rats ◽  
Testing Procedures ◽  
Threshold Response ◽  
Sympathetic Function ◽  
Microvascular Pathology ◽  
Juvenile Diabetic

Microvascular pathology and sympathetic autonomic dysfunction have been described early in alloxan-induced diabetic juvenile rats. To determine the longitudinal development of these changes and whether insulin treatment can alter them, vascular and sympathetic function were studied in alloxan-induced (42.5 mg/kg) juvenile diabetic rats and saline-treated controls. The rats were examined 1 and 14 days after induction of diabetes. An insulin-treated group was studied with the 14-day group. Hindquarter perfusion with an artificial solution at constant flow/100 g hindquarter wt was used. After 14 days of diabetes mellitus, the diabetic group showed a significantly depressed response to central ischemia (P less than 0.001), maximal vasoconstriction (P less than 0.02), and maximal dilation (P less than 0.001) compared with both the control and insulin-treated group. The threshold response to norepinephrine did not differ. After 1 day of glucose elevation no differences were present between the control and diabetic animals during any of the testing procedures. These results suggest that severe vascular dysfunction develops early in juvenile-onset alloxan diabetes and that it can be prevented with insulin treatment.

scholarly journals Expression of Urotensin II During Focal Cerebral Ischemic in Diabetic Rats

2014 ◽  
Vol 41 (4) ◽  
pp. 498-503 ◽  
Author(s):  
Lin Tian ◽  
Yunqian Li ◽  
Wei Hua ◽  
Ying Jia ◽  
Min Zhou ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Cerebral Ischaemia ◽  
Artery Occlusion ◽  
Diabetic Rats ◽  
Focal Cerebral Ischaemia ◽  
Urotensin Ii ◽  
Sprague Dawley ◽  
Protein Levels ◽  
Ischaemic Brain ◽  
Cerebral Ischemic

Background:The objective of this study was to explore the expression of urotensin II (UII), its receptor (GPR14), and vascular endothelial growth factor (VEGF), as well as their associations in the ischaemic brains of rats with focal cerebral ischaemia, under normal and diabetic conditions.Methods:Diabetes mellitus (DM) was induced by injection of streptozotocin (STZ) into Sprague—Dawley rats. Focal cerebral ischaemia was induced by middle cerebral artery occlusion (MCAO) four weeks after DM onset by STZ. Rats (n=80) were divided into four groups: normal control, DM, MCAO, and DM/MCAO. Immunohistochemistry and reverse-transcriptase-polymerase chain reaction (RT-PCR) were used to detect the expression of UII, GPR14 and VEGF in the diabetic and ischaemic brain.Results:Expression of UII and GPR14 was increased at mRNA and protein levels in the DM and MCAO group compared with controls. In the DM/MCAO group, expression of UII and GPR14 was increased significantly in the ischaemic brain, and was accompanied by a significantly increased VEGF expression.Conclusion:Diabetes mellitus was seen to aggravate brain lesions after ischaemia, and UII may have an important role.

scholarly journals Mammalian Tribbles homolog 3 impairs insulin action in skeletal muscle: role in glucose-induced insulin resistance

2010 ◽  
Vol 298 (3) ◽  
pp. E565-E576 ◽  
Author(s):  
Jiarong Liu ◽  
Xuxia Wu ◽  
John L. Franklin ◽  
Joseph L. Messina ◽  
Helliner S. Hill ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Skeletal Muscle ◽  
Glucose Transporter ◽  
Vastus Lateralis ◽  
Glucose Deprivation ◽  
Muscle Cells ◽  
Diabetic Rats ◽  
Glucose Disposal ◽  
Insulin Resistant ◽  
Protein Levels

Tribbles homolog 3 (TRIB3) was found to inhibit insulin-stimulated Akt phosphorylation and modulate gluconeogenesis in rodent liver. Currently, we examined a role for TRIB3 in skeletal muscle insulin resistance. Ten insulin-sensitive, ten insulin-resistant, and ten untreated type 2 diabetic (T2DM) patients were metabolically characterized by hyperinsulinemic euglycemic glucose clamps, and biopsies of vastus lateralis were obtained. Skeletal muscle samples were also collected from rodent models including streptozotocin (STZ)-induced diabetic rats, db/db mice, and Zucker fatty rats. Finally, L6 muscle cells were used to examine regulation of TRIB3 by glucose, and stable cell lines hyperexpressing TRIB3 were generated to identify mechanisms underlying TRIB3-induced insulin resistance. We found that 1) skeletal muscle TRIB3 protein levels are significantly elevated in T2DM patients; 2) muscle TRIB3 protein content is inversely correlated with glucose disposal rates and positively correlated with fasting glucose; 3) skeletal muscle TRIB3 protein levels are increased in STZ-diabetic rats, db/db mice, and Zucker fatty rats; 4) stable TRIB3 hyperexpression in muscle cells blocks insulin-stimulated glucose transport and glucose transporter 4 (GLUT4) translocation and impairs phosphorylation of Akt, ERK, and insulin receptor substrate-1 in insulin signal transduction; and 5) TRIB3 mRNA and protein levels are increased by high glucose concentrations, as well as by glucose deprivation in muscle cells. These data identify TRIB3 induction as a novel molecular mechanism in human insulin resistance and diabetes. TRIB3 acts as a nutrient sensor and could mediate the component of insulin resistance attributable to hyperglycemia (i.e., glucose toxicity) in diabetes.

scholarly journals Effects of Extracts of Plathymenia Reticulata Benth and Azadirachta Indica (Neem) in Glycated Hemoglobin in Diabetic Rats

2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. A438-A439
Author(s):  
Ezio De Martino Neto ◽  
Joyce Satil Chaves da Silva ◽  
Eliane Cristina Lourenço ◽  
Arthur Cesário de Castro Neto ◽  
Isabella Cecilio Resende Ferreira ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Azadirachta Indica ◽  
Insulin Treatment ◽  
Glycated Hemoglobin ◽  
Positive Control ◽  
Negative Control ◽  
Diabetic Rats ◽  
Male Adult ◽  
Significant Difference

Abstract Introduction: The Plathymenia reticulata benth is a herbal medicine that has properties of pancreatic islet hyperplasia and glycemic control in diabetic rats. Neem (Azadirachta indica A. Juss, Meliaceae) is a tree native to India that has several medicinal effects. Goal: To verify the effect of glycated hemoglobin levels in rats with type 1 and non-diabetic diabetes mellitus, in treatment with Plathymenia Reticulata Benth, Neem and the association between them. compared to insulin. Methodology: Diabetes was induced by intraperitoneal streptozotocin (65mg/kg) administration after a 24-hour fast. The diagnosis was made using a blood glucose value above 200mg/dl. The study was conducted in 60 male adult Wistar rats, weighing between 180 and 220 grams, divided into 9 groups, between diabetics (DM) and non-diabetic controls (NdM), and treated with Neem (300 mg/kg), cold aqueous extract of Plathymenia (100 mg/kg), water (negative control) and insulin (3 IU/day) - positive control; and association between plants. The treatment was performed by orogastric gavage for a period of 28 consecutive days, and weekly weight and daily feed intake were performed. Data were analyzed using ANOVA and Tukey-Kramer’s pos-hoc test, with a significance level of 5% using the SPSS25.0 software. The results are expressed on average ± EPM. Results: There was a significant difference in glycated hemoglobin levels in rats submitted to insulin treatment (6.18 ± 0.36) compared to those submitted to treatment with Neem (10.12 ± 1.29, p=0.047), Plathymenia+Neem (12.09 ± 0.38, p=0.006) and water (10.86 ± 1.26, p=0.015). However, no significant difference was observed between the reduction in glycated hemoglobin levels in the groups submitted to insulin treatment compared to the group treated with Plathymenia (7.30 ± 0.68, p=0.911). Conclusion: The results allow us to evaluate a non-inferiority condition in relation to the use of the Plathymenia when compared to treatment with insulin therapy, positive control in the treatment of type 1 diabetes mellitus. The Plathymeniamay present as a herbal option in the treatment of the disease and prevention of complications. Further studies are necessary to evaluate the effect of the extract on other aspects related to the pathology.

Altered renal expression of the insulin-responsive glucose transporter GLUT4 in experimental diabetes mellitus

1994 ◽  
Vol 267 (5) ◽  
pp. F816-F824 ◽  
Author(s):  
R. G. Marcus ◽  
R. England ◽  
K. Nguyen ◽  
M. J. Charron ◽  
J. P. Briggs ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Glucose Uptake ◽  
Glucose Transporter ◽  
Experimental Diabetes ◽  
Diabetic Rats ◽  
Experimental Diabetes Mellitus ◽  
Early Diabetes ◽  
Glut4 Expression ◽  
Microvascular Cells ◽  
Glucose Transporter Glut4

Because the insulin-responsive glucose transporter, GLUT4, is expressed in renal vascular and glomerular cells, we determined the effects of experimental diabetes mellitus on GLUT4 expression and glucose uptake by these tissues. Quantitative reverse-transcription polymerase chain reaction studies of microdissected afferent microvessels and renal glomeruli showed that, after 1 wk of diabetes, GLUT4 mRNA was decreased to 26 and 34% of control values, respectively. GLUT4 immunoblots of renal glomerular and microvessel samples showed that GLUT4 polypeptide was decreased to 51% of control values. These results were confirmed by indirect immunofluorescence, which showed decreased GLUT4 expression in glomerular cells and in vascular smooth muscle cells of the afferent microvasculature of diabetic animals. Uptake of the glucose analogue, 2-deoxyglucose, was also depressed in microvessels of diabetic rats to 57% of control values, supporting the conclusion that fewer total glucose transporters were available for glucose uptake into diabetic renal glomerular and microvascular cells. Thus both GLUT4 expression and glucose uptake by glomerular and microvascular cells are decreased in diabetic animals. These results have led us to suggest a mechanism by which decreased renal GLUT4 expression could contribute to glomerular hyperfiltration and hypertension seen in early diabetes.

Stability of GLUT-1 and GLUT-4 expression in perfused rat muscle stimulated by insulin and exercise

1995 ◽  
Vol 78 (1) ◽  
pp. 46-52 ◽  
Author(s):  
X. X. Han ◽  
A. Handberg ◽  
L. N. Petersen ◽  
T. Ploug ◽  
H. Galbo
Keyword(s):  
Glucose Transporter ◽  
Glut 1 ◽  
Protein Levels ◽  
Glut 4 ◽  
Slow Twitch ◽  
Glucose Transporter Mrna ◽  
Fast Twitch ◽  
Transporter Expression

In vivo exercise and insulin may change the concentrations of GLUT-4 protein and mRNA in muscle. We studied in vitro whether adaptations in glucose transporter expression are initiated during a single prolonged period of contractions or during insulin stimulation. Rat hindquarters were perfused at 7 mM glucose for 2 h with or without insulin (> 20,000 microU/ml) while the sciatic nerve of one leg was stimulated to produce repeated tetanic contractions. During electrical stimulation, contraction force decreased 93 +/- 1% (SE; n = 26) and muscle glycogen was markedly diminished (P < 0.05). Both contractions and insulin markedly increased glucose transport and uptake (P < 0.05). At the end of contractions, glycogen was higher in the presence of than in the absence of insulin (24 +/- 4 vs. 14 +/- 3 mumol/g for the soleus and 13 +/- 2 vs. 8 +/- 1 mumol/g for the red gastrocnemius, respectively; P < 0.05). In nonstimulated muscle, glucose transporter mRNA and protein concentrations were higher in the soleus than in the white gastrocnemius (GLUT-4 mRNA 184 +/- 18 vs. 131 +/- 36 arbitrary units; GLUT-1 mRNA 173 +/- 29 vs. 114 +/- 26 arbitrary units; GLUT-4 protein 0.96 +/- 0.09 vs. 0.46 +/- 0.03 arbitrary units; GLUT-1 protein 0.41 +/- 0.08 vs. 0.19 +/- 0.05 arbitrary units, respectively; P < 0.05). These concentrations were not changed by contractions or insulin. In conclusion, GLUT-1 and GLUT-4 mRNA and protein levels are higher in slow-twitch oxidative than in fast-twitch glycolytic fibers.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Transcriptional regulation of rat liver protein disulphide-isomerase gene by insulin and in diabetes

1990 ◽  
Vol 267 (2) ◽  
pp. 317-323 ◽  
Author(s):  
A Nieto ◽  
E Mira ◽  
J G Castaño
Keyword(s):  
Rat Liver ◽  
Insulin Treatment ◽  
Diabetic Rats ◽  
Regulation Of Transcription ◽  
Liver Protein ◽  
Gene Encoding ◽  
Protein Disulphide Isomerase ◽  
Multifunctional Protein ◽  
Protein Levels

The mRNA encoding for rat protein disulphide-isomerase (PDI) increases 3-fold in the liver of diabetic rats and is accompanied by similar changes at the protein level. Long treatment (for 3 days) of diabetic rats with insulin reverses this effect of diabetes both at the mRNA and protein levels. The higher expression of rat PDI mRNA in diabetes is due to an increase in the transcriptional rate of the gene, and insulin treatment of diabetic animals produces within 30 min a decrease in the level of transcription of PDI gene, as judged by nuclear run-on transcription experiments performed in vivo. These results clearly show a role for insulin in the regulation of transcription of the gene encoding this multifunctional protein in rat liver.

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