Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 16 de 16
Filter
1.
Article in English | MEDLINE | ID: mdl-34659435

ABSTRACT

In rats with 2-deoxy-2-(3-(methyl-3-nitrosoureido)-d-glucopyranose streptozotocin- (STZ-) induced insulin-dependent diabetes (IDDM), continuous 15 Hz electrical stimulation at bilateral ST36 acupoints for 30 and 60 minutes has been shown to prevent hyperglycemia. We hypothesized that the mechanism of action in STZ-induced IDDM rats is that electrical stimulation at bilateral ST36 acupoints is effective in improving insulin receptor substrate type 1 (IRS-1) and glucose transporter type 4 (GLUT4) protein expressions associated with counteracting both plasma glucose and free fatty acid (FFA) levels during isoflurane anesthesia. In this study, twenty-six healthy male Wistar rats, weighing 250-350 g and aged 8-10 weeks were tested. Rats in the experimental electroacupuncture (EA) group (n = 13) received 15 Hz electrical stimulation at bilateral ST 36 acupoints for 30 and 60 minutes. Rats in the control group (n = 13) were handled but not subjected to the stimulation treatment. In both IDDM and normal Wistar rats, we observed a negative change in plasma glucose levels when rats were given the EA treatment, but a positive change in plasma glucose without EA treatment relative to baseline. Within the IDDM group, a negative change in FFA levels was observed when rats were given the EA treatment, while a positive change in the FFA level was shown without the EA treatment. In the expressed protein signals, we found a significant elevation in both GLUT4 and IRS-1 proteins in the IDDM group treated by EA. Moreover, we found a significant mean difference between GLUT4 and IRS-1 protein expression levels relative to ß-actin. Our findings suggested that EA at bilateral ST36 acupoints could serve as an effective strategy for lowering plasma glucose by decreasing free fatty acid levels and improving the expression of IRS-1 and GLUT4 proteins in a STZ-IDDM rat model during isoflurane anesthesia.

2.
Med Acupunct ; 33(1): 58-64, 2021 Feb 01.
Article in English | MEDLINE | ID: mdl-33613812

ABSTRACT

Objective: Antrodia cinnamomea (AC), a medicinal mushroom indigenous to Taiwan, exerts various pharmacologic activities. This study compared and evaluated the hypoglycemic effect of treatment with electroacupuncture (EA) combined with AC in steroid-induced insulin-resistant (SIIR) rats. Materials and Methods: Rats were divided into saline, EA, AC, AC+EA, and rosiglitazone (TZD) groups. Plasma-glucose levels were measured in serial blood samples and compared before and after treatment in each group. The levels of signaling proteins-glucose transporter 4, (GLUT4), phosphoinositide 3-kinase (PI3-K), and 5' adenosine monophosphate-activated protein kinase (AMPK)-were analyzed by Western blotting to explore their mechanisms of action. Results: The AC+EA group had reduced plasma-glucose levels at 30 and 60 minutes in SIIR rats, compared to normal rats, and this was better than the EA, AC, and TZD groups at 60 minutes. Furthermore, the signaling protein (GLUT4, PI3-K, and AMPK) levels were increased significantly. Conclusions: These findings showed improved hypoglycemic activity and insulin resistance after EA combined with AC treatment. Therefore, the combined therapy might be a more-effective method than the individual therapies that elevates the expression of the signal proteins, as observed in this study.

3.
Biomed Pharmacother ; 129: 110328, 2020 Sep.
Article in English | MEDLINE | ID: mdl-32535384

ABSTRACT

The aim of the present study was to investigate the analgesic effects and mechanism of action of Trametes versicolor (Tv) mycelium powder. Wistar rats were randomly divided into the following three or four groups: i) Saline group, fed saline; ii) Tv 500 group, fed 500 mg/kg Tv; iii) ASA 50 group, fed 50 mg/kg acetylsalicylic acid (ASA); and iv) ASA 100 group, fed 100 mg/kg ASA. Chemical formalin tests and thermal hot plate tests were used to investigate the analgesic effects of each group. ELISAs were performed to detect cyclooxygenase-2 (COX-2) and prostaglandin E2 (PGE2) plasma levels, and high-performance liquid chromatography (HPLC) was used for quality control the active component, oleanolic acid (OA) in Tv that had the analgesic effect. The OA content in aqueous Tv extract was found to be 11.92 % by HPLC assays. The licking frequencies in the early phase and late phase of the formalin test were significantly lower in the Tv 500 and ASA 100 groups than the saline group. The licking time in the late phase were also significantly lower in the Tv 500 and ASA 100 groups than the saline group. The plasma levels of COX-2 and PGE2 were decreased significantly in the Tv 500 and ASA 100 groups compared with that of the saline group at 60 min in the formalin test. In addition, oral feeding with 500 mg/kg Tv may effectively reduce physical pain triggered by hot plates in Wistar rats. Taken together, the acetylsalicylic acid-like analgesic effects of Tv in Wistar rats may be associated with the reduction of the plasma COX-2 and PGE2 levels.


Subject(s)
Analgesics/pharmacology , Aspirin/pharmacology , Oleanolic Acid/pharmacology , Pain Threshold/drug effects , Pain/prevention & control , Polyporaceae , Analgesics/isolation & purification , Animals , Cyclooxygenase 2/blood , Dinoprostone/blood , Disease Models, Animal , Down-Regulation , Male , Oleanolic Acid/isolation & purification , Pain/blood , Pain/etiology , Pain/physiopathology , Polyporaceae/chemistry , Rats, Wistar
4.
Acupunct Med ; 38(5): 335-342, 2020 10.
Article in English | MEDLINE | ID: mdl-32297559

ABSTRACT

BACKGROUND: Previous studies have reported that electroacupuncture (EA) induces a glucose-lowering effect by improving insulin resistance (IR) and reduces plasma free fatty acid (FFA) levels in rats with steroid-induced insulin resistance (SIIR). In addition, EA can activate cholinergic nerves and stimulate endogenous opioid peptides to lower plasma glucose in streptozotocin-induced hyperglycemic rats. The aim of this study was to investigate the glucose-lowering effects of 15 Hz EA at bilateral ST36 in combination with acarbose (ACA). We hypothesized that EA combined with ACA would produce a stronger glucose-lowering effect than ACA alone. METHODS: In this study, normal Wistar rats and SIIR rats were randomly divided into two groups: ACA and ACA + EA. To explore the potential mechanisms underlying the glucose-lowering effect, plasma FFA/insulin and insulin transduction signal pathway proteins were assayed. RESULTS: Combined ACA + EA treatment had a greater glucose-lowering effect than ACA alone in normal Wistar rats (-45% ± 3% vs -19% ± 3%, p < 0.001) and SIIR model rats (-43% ± 2% vs -16% ± 6%, p < 0.001). A significant reduction in plasma FFA levels, improvement in homeostatic model assessment of IR (HOMA-IR) index (-48.9% ± 4.0%, p < 0.001) and insulin sensitivity index (102% ± 16.9%, p < 0.001), and significant increases in insulin receptor substrate 1, glucose transporter 4, and peroxisome proliferator-activated receptor γ protein expressions in skeletal muscle, were also observed in the ACA + EA group of SIIR rats. CONCLUSION: Combined EA and ACA therapy had a greater glucose-lowering effect than ACA monotherapy; this combined therapy could be more effective at improving IR in SIIR rats, which may be related to a reduction in plasma FFA levels and an elevation of insulin signaling proteins. Whether this combined therapy has an effect in type 2 diabetes mellitus (T2DM) patients still needs to be explored.


Subject(s)
Acarbose/administration & dosage , Electroacupuncture , Hyperglycemia/therapy , Insulin Resistance , PPAR gamma/metabolism , Steroids/adverse effects , Animals , Combined Modality Therapy , Glucose Transporter Type 4/genetics , Glucose Transporter Type 4/metabolism , Humans , Hyperglycemia/etiology , Hyperglycemia/genetics , Hyperglycemia/metabolism , Insulin/metabolism , Insulin Receptor Substrate Proteins/genetics , Insulin Receptor Substrate Proteins/metabolism , Male , Muscle, Skeletal/drug effects , Muscle, Skeletal/metabolism , PPAR gamma/genetics , Rats , Rats, Wistar
5.
Mol Med Rep ; 17(2): 3260-3266, 2018 Feb.
Article in English | MEDLINE | ID: mdl-29257321

ABSTRACT

Insulin resistance is a major factor in type II diabetes development, occurring when insulin levels are normal, but do not have normal interactions with adipose, muscle or liver tissue. The present study aimed to explore the hypoglycemic effect of Antrodia cinnamomea (AC) mycelium powder by evaluating its impact on insulin resistance and plasma free fatty acid (FFA) levels in steroid­induced insulin­resistant (SIIR) rats. Male Wistar rats were administered dexamethasone for 5 days to induce insulin resistance. The SIIR rats were subsequently randomly assigned into three experimental groups (EGs) and a control group (CG), where saline was orally administered. The EGs were orally administered different doses of AC (100, 200 or 500 mg/kg) and an optimal dose for further study was determined. Changes in plasma insulin and glucose levels were calculated to investigate the hypoglycemic effect of AC. To evaluate insulin resistance, the homeostasis model assessment­estimated insulin resistance of the SIIR rats was determined. Changes in plasma FFA levels were detected and levels of insulin signal proteins (IRS­1, GLUT­4 and PI3K) were analyzed by western blot to elucidate AC's mechanism of action. The SIIR rats exhibited significantly decreased plasma glucose levels in the first 30 min, with plasma FFA levels displaying a marked downward trend (P<0.05) when they were administered the optimal dose of AC (200 mg/kg). The decrease in plasma glucose and FFA levels was significantly larger in the EG compared to the CG, and insulin signal protein levels were also significantly increased (P<0.05). The hypoglycemic effect observed may be due to decreased plasma FFA levels and increased expression of intracellular insulin signal proteins. Furthermore, insulin sensitivity was enhanced, indicating that AC acts as an insulin sensitizer in insulin resistant animal models.


Subject(s)
Antrodia , Biological Products/therapeutic use , Blood Glucose/analysis , Hypoglycemic Agents/therapeutic use , Insulin Resistance , Insulin/blood , Animals , Antrodia/chemistry , Biological Products/chemistry , Dexamethasone , Hypoglycemic Agents/chemistry , Male , Rats, Wistar
6.
Acupunct Med ; 34(4): 296-301, 2016 Aug.
Article in English | MEDLINE | ID: mdl-26879182

ABSTRACT

OBJECTIVE: To evaluate the effect of electroacupuncture (EA) in a rat model of chronic steroid-induced insulin resistance (SIIR). METHODS: An SIIR rat model was created using daily intraperitoneal injections of clinically relevant doses of dexamethasone (1 mg/kg) for 5 days to induce chronic insulin resistance. Thirty-six SIIR rats were randomly divided into the SIIR+EA group (n=18), which received 15 Hz EA at ST36 for 60 min, and the SIIR group (n=18), which remained untreated. Plasma glucose and free fatty acid (FFA) levels were measured in serial blood samples taken without further manipulation (n=6 per group) and during insulin challenge test (ICT, n=6 per group) and intravenous glucose tolerance test (ivGTT, n=6 per group). Insulin receptor substrate (IRS)-1 and glucose transporter (GLUT)-4 were measured using Western blotting and expressed relative to ß-actin. RESULTS: Following EA, area-under-the-curve (AUC) for glucose was reduced (7340±291 vs 10 705±1474 mg/dL/min, p=0.049) and FFA levels significantly lower at 30/60 min in the SIIR+EA versus SIIR groups. Similar effects on glucose AUC were seen during the ICT (5568±275 vs 7136±594 mg/dL/min, p<0.05) and igVTT (11 498±1398 vs 16 652±1217 mg/dL/min, p<0.01). FFA levels were lower at 30 and/or 60 min in SIIR+EA versus SIIR groups (p<0.01). Relative expression of IRS-1 and GLUT4 were significantly increased by EA (p<0.01). CONCLUSIONS: EA decreased the FFA level and increased insulin sensitivity in SIIR rats. Further clinical studies are needed to determine whether EA is an effective alternative treatment for the reduction of insulin resistance in patients requiring chronic use of dexamethasone.


Subject(s)
Acupuncture Points , Electroacupuncture , Fatty Acids, Nonesterified/blood , Insulin Resistance , Animals , Blood Glucose/metabolism , Dexamethasone , Glucose Tolerance Test , Glucose Transporter Type 4/metabolism , Insulin Receptor Substrate Proteins/metabolism , Male , Rats , Rats, Wistar
7.
Acupunct Med ; 33(5): 395-9, 2015 Oct.
Article in English | MEDLINE | ID: mdl-26025382

ABSTRACT

BACKGROUND AND AIM: Previous animal studies have reported a glucose-lowering effect of electroacupuncture (EA) and suggested that the mechanisms are closely related to intracellular signalling pathways. The aim of this study was to screen for potential intracellular signalling pathways that are upregulated by EA at ST36 bilaterally in rats with diabetes mellitus (DM) using microarray analysis. METHODS: Streptozotocin (STZ)-induced diabetic rats were randomly assigned to experimental (EA, n=8) or control (non-EA, n=8) groups. Plasma glucose levels were measured at baseline and after 30 and 60 min, and microarray analysis was performed on samples of gastrocnemius muscle. RESULTS: Relative to baseline values, EA significantly reduced plasma levels of glucose at 30 and 60 min. The microarray pathway analysis showed that cell adhesion molecules and type 1 DM gene sets were both upregulated in EA versus non-EA groups (p<0.05). CONCLUSIONS: Cell adhesion molecules might be related to the glucose-lowering effect induced by EA in rats with STZ-induced type 1 diabetes. Further research will be required to examine the involvement of related intracellular signalling pathways.


Subject(s)
Blood Glucose/metabolism , Diabetes Mellitus, Experimental/therapy , Electroacupuncture , Signal Transduction , Animals , Diabetes Mellitus, Experimental/metabolism , Male , Rats, Wistar
8.
Phytother Res ; 29(5): 770-6, 2015 May.
Article in English | MEDLINE | ID: mdl-25712886

ABSTRACT

Xylaria nigripes (XN) is a medicinal fungus with a high-economic value. The aim of this study was to explore the hypoglycemic effects and mechanisms of the XN aqueous extract in steroid-induced insulin-resistant (SIIR) rats. Significant hypoglycemic effects were observed 60 min after administration of XN aqueous extract. In normal Wistar, hypoglycemic effects were 21% (the plasma glucose level decreased from 128.6 ± 12.5 to 100.9 ± 10.7 mg/dL). In SIIR, hypoglycemic effects were 26% (the plasma glucose level decreased from 177.6 ± 12.5 to 133.3 ± 29.7 mg/dL) rats refer to their baseline. The signaling proteins for insulin-receptor substrate-1 and glucose transporter-4 increased 0.51-fold and 1.12-fold, respectively, as determined by Western blotting; the increase in the proteins was 13% and 9%, respectively, as determined by immunohistochemistry. The serotonin antagonist, α-p-chlorophenylalanine, effectively blocked the hypoglycemic effects and increased the signaling protein levels. After XN administration, none of the animals showed significant changes in plasma-free fatty acids in 60 min. In summary, the XN extract may have hypoglycemic effects in normal Wistar and SIIR rats that may have a serotonin-related hypoglycemic effect and enhance insulin sensitivity in the SIIR rats.


Subject(s)
Biological Products/pharmacology , Hypoglycemic Agents/pharmacology , Insulin Resistance , Serotonin/metabolism , Xylariales/chemistry , Animals , Blood Glucose/drug effects , Fatty Acids, Nonesterified/blood , Fenclonine/pharmacology , Glucose Transporter Type 4/metabolism , Insulin/blood , Insulin Receptor Substrate Proteins/metabolism , Rats , Rats, Wistar , Serotonin Antagonists/pharmacology
9.
Article in English | MEDLINE | ID: mdl-25024728

ABSTRACT

The application of electroacupuncture (EA) to specific acupoints can induce a hypoglycemic effect in streptozotocin-induced rats, normal rats, and rats with steroid-induced insulin resistance. EA combined with the oral insulin sensitizer rosiglitazone improved insulin sensitivity in rats and humans with type II diabetes mellitus (DM). There are different hypoglycemic mechanisms between Zhongwan and Zusanli acupoints by EA stimulation. On low-frequency (2 Hz) stimulation at bilateral Zusanli acupoints, serotonin was involved in the hypoglycemic effect in normal rats. Moreover, after 15 Hz EA stimulation at the bilateral Zusanli acupoints, although enhanced insulin activity mainly acts on the insulin-sensitive target organs, the muscles must be considered. In addition, 15 Hz EA stimulation at the bilateral Zusanli acupoints has the combined effect of enhancing cholinergic nerve activity and increasing nitric oxide synthase (NOS) activity to enhance insulin activity. Despite the well-documented effect of pain control by EA in many systemic diseases, there are few high-quality long-term clinical trials on the hypoglycemic effect of EA in DM. Combination treatment with EA and other medications seems to be an alternative treatment to achieve better therapeutic goals that merit future investigation.

10.
BMC Complement Altern Med ; 14: 30, 2014 Jan 18.
Article in English | MEDLINE | ID: mdl-24438349

ABSTRACT

BACKGROUND: The active components of Gardenia (Gardenia jasminoides Ellis, GJ) exhibit a hypoglycemic effect by improving insulin secretion and lowering plasma lipids. In the present study, we fed a water extract of gardenia to steroid-induced insulin-resistant (SIIR) rats and observed changes in signaling proteins in order to elucidate the mechanisms of the insulin-sensitizing effect of GJ and evaluate its possibility as an insulin-sensitizing agent. METHODS: Normal Wistar rats were randomly divided into a control group (i.e., saline) and experimental groups (GJ 100 and 200 mg/kg). Blood samples were taken at 0, 30, and 60 min for plasma glucose assay in order to determine the optimal dose to induce the hypoglycemic effect. SIIR rats were then randomly divided into a control group (i.e., saline) and an experimental group (optimal dose of gardenia extract) to observe the insulin-sensitizing effect of the extract. Finally, western blot analysis was performed to detect intracellular signaling proteins to elucidate the mechanisms of the insulin-sensitization effect of GJ. RESULTS: The normal Wistar rats in the GJ 200 mg/kg group exhibited significant hypoglycemic activity. Meanwhile, the SIIR rats had higher plasma glucose levels than normal rats. There was no obvious change in insulin level, but the insulin sensitivity index and homeostasis model assessment index were significantly elevated. Meanwhile, a significant hypoglycemic effect was observed with GJ 200 mg/kg. In addition, intracellular signaling proteins including insulin receptor substrate-1 (IRS-1) and peroxisome proliferator-activated receptor (PPARγ) were elevated in muscle cells. CONCLUSIONS: The optimal dose of GJ aqueous extract of 200 mg/kg exerts a PPARγ-activating hypoglycemic effect and improves insulin resistance in SIIR rats. Therefore, it is a potential insulin-sensitizing agent in type 2 diabetes mellitus with insulin resistance.


Subject(s)
Diabetes Mellitus, Type 2/blood , Gardenia , Hypoglycemic Agents/pharmacology , Insulin Resistance , Insulin/blood , Peroxisome Proliferator-Activated Receptors/metabolism , Plant Extracts/pharmacology , Animals , Blood Glucose/metabolism , Diabetes Mellitus, Type 2/drug therapy , Diabetes Mellitus, Type 2/metabolism , Hypoglycemic Agents/therapeutic use , Insulin Receptor Substrate Proteins/metabolism , Male , Muscles/drug effects , Muscles/metabolism , PPAR gamma/metabolism , Phytotherapy , Plant Extracts/therapeutic use , Rats, Wistar , Steroids
11.
Article in English | MEDLINE | ID: mdl-23983807

ABSTRACT

Aims. To evaluate the efficacy of rosiglitazone (TZD) and electroacupuncture (EA) combined therapy as a treatment for type 2 diabetes mellitus (T2DM) patients by randomized single-blind placebo controlled clinical trial. Methods. A total of 31 newly diagnostic T2DM patients, who fulfilled the study's eligibility criteria, were recruited. The individuals were randomly assigned into two groups, the control group (TZD, N = 15) and the experimental group (TZD + EA, N = 16). Changes in their plasma free fatty acid (FFA), glucose, and insulin levels, together with their homeostasis model assessment (HOMA) indices, were statistically compared before and after treatment. Hypoglycemic activity (%) was also compared between these two groups. Results. There was no significant difference in hypoglycemic activity between the TZD and TZD + EA group. The effectiveness of the combined therapy seems to derive from an improvement in insulin resistance and a significant lowering of the secreted insulin rather than the effect of TZD alone on T2DM. The combined treatment had no significant adverse effects. A lower plasma FFA concentration is likely to be the mechanism that causes this effect. Conclusion. This combined therapy seems to suppress endogenous insulin secretion by improving insulin resistance via a mechanism involving a reduction in plasma FFA. This trial is registered with ClinicalTrials.gov NCT01577095.

12.
Int J Med Mushrooms ; 15(3): 277-86, 2013.
Article in English | MEDLINE | ID: mdl-23662615

ABSTRACT

In our previous research, Cordyceps militaris (CM) had a hypoglycemic effect in normal rats. In this study we wanted to elucidate whether CM also had an effect on diabetic rats. Twelve rats with streptozotocin-induced diabetes were separated randomly into 2 groups. First, aqueous extracts of CM 10 mg/kg (CM group) or saline (control group) was fed to the rats; then the plasma glucose levels were assayed. Second, the signaling proteins IRS-1 and GLUT-4 collected from the muscle were detected. Finally, another 2 groups of rats were injected with atropine 0.1 mg/kg intraperitoneally just before the CM/saline feeding, and the assays mentioned above were repeated. Blood glucose decreased 7.2% in the CM group but only 1.5% in the control group (P < 0.05). The IRS-1 signal was 2.9-fold higher than actin in the CM group but only 0.8-fold higher in the control group (P < 0.005). In GLUT-4 signal, the difference was 1.7- vs. 0.6-fold, respectively, compared with actin (P < 0.05). However, atropine injection made CM-induced hypoglycemia or elevation of IRS-1 and GLUT-4 not significant. In conclusion, CM had a hypoglycemic effect in diabetic rats and atropine blocked it. Therefore, the cholinergic activation also was considered to be involved in the hypoglycemic effect of CM in rats with streptozotocin-induced diabetes.


Subject(s)
Blood Glucose/drug effects , Cholinergic Agents/pharmacology , Cholinergic Fibers/drug effects , Cordyceps/chemistry , Diabetes Mellitus, Experimental/drug therapy , Hypoglycemic Agents/pharmacology , Animals , Atropine/antagonists & inhibitors , Chemical Fractionation , Cholinergic Agents/chemistry , Hypoglycemic Agents/chemistry , Male , Random Allocation , Rats , Rats, Wistar , Water
13.
Phytother Res ; 26(8): 1173-7, 2012 Aug.
Article in English | MEDLINE | ID: mdl-22821853

ABSTRACT

Previous studies have shown that Cordyceps militaris (CM) has a hypoglycemic effect, but the actual mechanism remains unclear. This study explored the hypoglycemic mechanism of aqueous extracts of CM in normal Wistar rats. First, the optimal dose of CM for lowering plasma glucose and insulin secretion was tested. Further, atropine and hemicholinium-3 (HC-3) were injected and a western blot was used to investigate insulin signaling. It was found that 10 mg/kg CM extracts had a stronger hypoglycemic effect than a higher dose (100 mg/kg); therefore, a dose of 10 mg/kg was used in subsequent experiments. In normal rats, CM extracts decreased plasma glucose by 21.0% and induced additional insulin secretion by 54.5% after 30 min. When atropine or HC-3 was injected, CM induced a hypoglycemic effect, but the enhancement of insulin secretion was blocked. By western blotting, significant increases in the insulin receptor substrate 1 (IRS-1) and glucose transporter 4 (GLUT-4) were observed after CM feeding. However, the elevation of these signaling proteins was abolished by atropine or HC-3. Taken together, these findings indicate that CM can lower plasma glucose via the stimulation of insulin secretion and cholinergic activation involved in the hypoglycemic mechanism of normal Wistar rats.


Subject(s)
Blood Glucose/drug effects , Cholinergic Agents/pharmacology , Cordyceps/chemistry , Hypoglycemic Agents/pharmacology , Insulin/metabolism , Animals , Atropine/administration & dosage , Atropine/pharmacology , Blood Glucose/metabolism , Blotting, Western , Cholinergic Fibers/drug effects , Cholinergic Fibers/metabolism , Disease Models, Animal , Glucose Transporter Type 4/metabolism , Hemicholinium 3/administration & dosage , Hemicholinium 3/pharmacology , Insulin Receptor Substrate Proteins/metabolism , Insulin Secretion , Male , Rats , Rats, Wistar
14.
Article in English | MEDLINE | ID: mdl-21799686

ABSTRACT

Animal studies have shown that electroacupuncture (EA) at Zusanli (ST-36) and Zhongwan (CV-12) acupoints reduces plasma glucose concentrations in rats with type II diabetes. However, whether EA reduces plasma glucose levels in type I diabetes is still unknown. In this study, we explore the various non-insulin-dependent pathways involved in EA-induced lowering of plasma glucose. Streptozotocin (STZ) (60 mg kg(-1), i.v.) was administered via the femoral vein to induce insulin-dependent diabetes in non-adrenalectomized and in adrenalectomomized rats. EA (15 Hz) was applied for 30 min to bilateral ST-36 acupoints after administration of Atropine (0.1 mg kg(-1) i.p.), Eserine (0.01 mg kg(-1) i.p.), or Hemicholinium-3 (5 µg kg(-1) i.p.) in non-adrenalectomized rats. Rats administered acetylcholine (0.01 mg kg(-1) i.v.) did not undergo EA. Adrenalectomized rats underwent EA at bilateral ST-36 acupoints without further treatment. Blood samples were drawn from all rats before and after EA to measure changes in plasma glucose levels. Expression of insulin signaling proteins (IRS1, AKT2) in atropine-exposed rats before and after EA was measured by western blot. Atropine and hemicholinium-3 completely blocked the plasma glucose lowering effects of EA, whereas eserine led to a significant hypoglycemic response. In addition, plasma glucose levels after administration of acetylcholine were significantly lower than the fasting glucose levels. In STZ-adrenalectomized rats, EA did not induce a hypoglycemic response. EA stimulated the expression of IRS1 and AKT2 and atropine treatment blocked the EA-induced expression of those insulin signaling proteins. Taken together, EA at the ST-36 acupoint reduces plasma glucose concentrations by stimulating the cholinergic nerves.

15.
Exp Diabetes Res ; 2011: 947138, 2011.
Article in English | MEDLINE | ID: mdl-21754922

ABSTRACT

The aim of this study is to explore the mechanisms by which electroacupuncture (EA) enhances the hypoglycemic effect of exogenous insulin in a streptozotocin- (STZ-) diabetic rats. Animals in the EA group were anesthetized and subjected to the insulin challenge test (ICT) and EA for 60 minutes. In the control group, rats were subjected to the same treatment with the exception of EA stimulation. Blood samples were drawn to measure changes in plasma glucose, free fatty acids (FFA), and insulin levels. Western blot was used to assay proteins involved in insulin signaling. Furthermore, atropine, hemicholinium-3 (HC-3), and Eserine were used to explore the relationship between EA and cholinergic nerve activation during ICT. EA augmented the blood glucose-lowering effects of EA by activating the cholinergic nerves in STZ rats that had been exposed to exogenous insulin. This phenomenon may be related to enhancement of insulin signaling rather than to changes in FFA concentration.


Subject(s)
Blood Glucose/metabolism , Cholinergic Fibers/drug effects , Cholinergic Fibers/physiology , Diabetes Mellitus, Experimental/metabolism , Electroacupuncture , Hypoglycemic Agents/pharmacology , Insulin/pharmacology , Animals , Atropine/pharmacology , Cholinergic Agents/pharmacology , Diabetes Mellitus, Experimental/chemically induced , Disease Models, Animal , Fatty Acids, Nonesterified/blood , Hemicholinium 3/pharmacology , Insulin/blood , Male , Physostigmine/pharmacology , Rats , Rats, Wistar , Signal Transduction/drug effects , Signal Transduction/physiology , Streptozocin/adverse effects
16.
Neurosci Lett ; 494(2): 114-8, 2011 Apr 25.
Article in English | MEDLINE | ID: mdl-21376780

ABSTRACT

The purpose of this investigation was to evaluate the effect and mechanisms of electroacupuncture (EA) at the bilateral Zusanli acupoints (ST-36) on glucose tolerance in normal rats. Intravenous glucose tolerance test (IVGTT) was performed to examine the effects of electroacupuncture (EA) on glucose tolerance in rats. The EA group underwent EA at the ST-36, with settings of 15 Hz, 10 mA, and 60 min; the control group underwent the same treatments, but without EA. Atropine, hemicholinium-3 (HC-3) or NG-nitro-L-arginine methyl ester (L-NAME) were injected into the rats alone or simultaneously and EA was performed to investigate differences in plasma glucose levels compared to the control group. Plasma samples were obtained for assaying plasma glucose and free fatty acid (FFA) levels. Western blot was done to determine the insulin signal protein and nNOS to exam the correlation between EA and improvement in glucose tolerance. The EA group had significantly lower plasma glucose levels compared to the control group. Plasma glucose levels differed significantly between the EA and control groups after the administration of L-NAME, atropine, or HC-3 treatments alone, but there were no significant differences in plasma glucose with combined treatment of L-NAME and atropine or L-NAME and HC-3. EA decreased FFA levels and enhanced insulin signal protein (IRS1) and nNOS activities in skeletal muscle during IVGTT. In summary, EA stimulated cholinergic nerves and nitric oxide synthase for lowering plasma FFA levels to improve glucose tolerance.


Subject(s)
Blood Glucose/metabolism , Electroacupuncture , Neurons/metabolism , Nitric Oxide Synthase Type I/metabolism , Acetylcholine/metabolism , Animals , Fatty Acids, Nonesterified/blood , Glucose Tolerance Test , Insulin Receptor Substrate Proteins/metabolism , Male , Rats , Rats, Wistar
SELECTION OF CITATIONS
SEARCH DETAIL
...