Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 20
Filter
1.
Braz J Med Biol Res ; 57: e13066, 2024.
Article in English | MEDLINE | ID: mdl-38265342

ABSTRACT

Health literacy (HL) is defined as a cognitive and social skill that determines the motivation and ability of individuals to understand and use information to promote and maintain proper health. Inadequate HL has been associated with worse outcomes in diabetes control, poor self-care, and higher hospitalization rates for some chronic diseases. We hypothesized that HL influences the prevalence of diabetic retinopathy (DR) among individuals with type 2 diabetes mellitus (T2DM) and that inadequate glycemic control would mediate this association. This was a cross-sectional study carried out with 288 participants of the "Brazilian Diabetes Study" cohort. Inclusion criteria were people diagnosed with T2DM aged between 40 and 70 years and ability to read and write. In the adequate HL group, DR was found in 16.5% of participants and in the inadequate HL group, it was found in 32.8% (P=0.0081). Individuals with inadequate HL had a higher risk of having DR, and this association was still statistically significant after adjusting for HbA1c, low-density lipoprotein cholesterol, systolic blood pressure, and diastolic blood pressure. In conclusion, HL is related to DR without the mediation of classical clinical variables.


Subject(s)
Diabetes Mellitus, Type 2 , Diabetic Retinopathy , Health Literacy , Humans , Adult , Middle Aged , Aged , Cross-Sectional Studies , Brazil
2.
Braz. j. med. biol. res ; 57: e13066, 2024. tab
Article in English | LILACS-Express | LILACS | ID: biblio-1528103

ABSTRACT

Health literacy (HL) is defined as a cognitive and social skill that determines the motivation and ability of individuals to understand and use information to promote and maintain proper health. Inadequate HL has been associated with worse outcomes in diabetes control, poor self-care, and higher hospitalization rates for some chronic diseases. We hypothesized that HL influences the prevalence of diabetic retinopathy (DR) among individuals with type 2 diabetes mellitus (T2DM) and that inadequate glycemic control would mediate this association. This was a cross-sectional study carried out with 288 participants of the "Brazilian Diabetes Study" cohort. Inclusion criteria were people diagnosed with T2DM aged between 40 and 70 years and ability to read and write. In the adequate HL group, DR was found in 16.5% of participants and in the inadequate HL group, it was found in 32.8% (P=0.0081). Individuals with inadequate HL had a higher risk of having DR, and this association was still statistically significant after adjusting for HbA1c, low-density lipoprotein cholesterol, systolic blood pressure, and diastolic blood pressure. In conclusion, HL is related to DR without the mediation of classical clinical variables.

3.
Braz J Med Biol Res ; 56: e12640, 2023.
Article in English | MEDLINE | ID: mdl-37194835

ABSTRACT

Diabetes mellitus is associated with impaired wound healing. The topical use of insulin is a promising therapy because it may favor all phases of the wound healing process. This study aimed to investigate the therapeutic outcomes of insulin gel in wounds of hyperglycemic mice. After diabetes induction, a 1-cm2 full-thickness wound was created on each animal's dorsum. The lesions were treated daily for 14 days with insulin gel (insulin group) or vehicle gel without insulin (vehicle group). Tissue samples were extracted on days 4, 7, 10, and 14 after the creation of the lesion. The samples were analyzed with hematoxylin/eosin and Sirius red staining, immunohistochemistry, Bio-Plex immunoassays, and western blotting. Insulin gel favored re-epithelialization at day 10 and increased the organization and deposition of collagen. Additionally, it modulated the expression of cytokines (interleukin (IL)-4 and IL-10) and increased the expression of arginase I, VEGF receptor 1, and VEGF on day 10. Activation of the insulin signaling pathway occurred via IRß, IRS1, and IKK on day 10 and activation of Akt and IRS1 on day 14. These results suggested that insulin gel improved wound healing in hyperglycemic mice by modulating the expression of inflammatory factors, growth factors, and proteins of the insulin signaling pathway.


Subject(s)
Insulin , Procollagen , Mice , Animals , Mice, Obese , Wound Healing , Anti-Inflammatory Agents
4.
Braz. j. med. biol. res ; 56: e12640, 2023. tab, graf
Article in English | LILACS-Express | LILACS | ID: biblio-1439705

ABSTRACT

Diabetes mellitus is associated with impaired wound healing. The topical use of insulin is a promising therapy because it may favor all phases of the wound healing process. This study aimed to investigate the therapeutic outcomes of insulin gel in wounds of hyperglycemic mice. After diabetes induction, a 1-cm2 full-thickness wound was created on each animal's dorsum. The lesions were treated daily for 14 days with insulin gel (insulin group) or vehicle gel without insulin (vehicle group). Tissue samples were extracted on days 4, 7, 10, and 14 after the creation of the lesion. The samples were analyzed with hematoxylin/eosin and Sirius red staining, immunohistochemistry, Bio-Plex immunoassays, and western blotting. Insulin gel favored re-epithelialization at day 10 and increased the organization and deposition of collagen. Additionally, it modulated the expression of cytokines (interleukin (IL)-4 and IL-10) and increased the expression of arginase I, VEGF receptor 1, and VEGF on day 10. Activation of the insulin signaling pathway occurred via IRβ, IRS1, and IKK on day 10 and activation of Akt and IRS1 on day 14. These results suggested that insulin gel improved wound healing in hyperglycemic mice by modulating the expression of inflammatory factors, growth factors, and proteins of the insulin signaling pathway.

5.
Med Oral Patol Oral Cir Bucal ; 26(1): e14-e20, 2021 Jan 01.
Article in English | MEDLINE | ID: mdl-33247577

ABSTRACT

BACKGROUND: Head and neck radiotherapy is typically associated with toxicities that can have profound effects on the patient's quality of life. Xerostomia, which may or may not be related to hypofunction of the salivary gland, leading to negative consequences, mainly in quality of life, leaving patients more susceptible to the development of oral mucositis, dental caries, oral infection and difficulties in speech is one of the most common side effects of such treatment. The aim of the present study was to evaluate salivary function of patients in treatment with radiotherapy for head and neck cancer submitted to photobiomodulation. MATERIAL AND METHODS: A cross-sectional study with a quantitative approach was carried out in the Dentistry Department of the Hospital de Câncer de Pernambuco between February and September 2019. RESULTS: The study sample comprised 23 patients of both genders, treated with radiotherapy for cancer in the head and neck region. The patients were submitted to photobiomodulation with infrared laser, as intraoral applications in order to prevent mucositis and extraoral applications to stimulate salivary glands. The applications were undertaken three times a week on alternate days throughout the radiotherapy period. The following parameters were used: Intraoral 15mW, 12J / cm2, 10s / point, 2.4 J / point, and extraoral 30mW, 7.5J / cm2, 10s / point, 0.3J / point, both with a wavelength of 830nm and area of 0.028cm². Subjective and objective symptoms were evaluated by measuring the unstimulated salivary flow (USF) using the spitting technique before, during and after radiotherapy treatment. For statistical analysis, a significance level of 5% was adopted. Most patients were male (70%) with 60 years of age on average. At the beginning of treatment, 22 patients had USF > 0.2 ml / min (grade 1), at the end of which 15 patients remained unchanged and only 3 patients progressed to grade 3. As for the subjective classification, most (52%) remained in grade 1 (absence of disability) throughout the treatment. CONCLUSION: Based upon the results of this study it was possible to conclude that the use of photobiomodulation did not significantly interfere with the xerostomia complaint of patients in treatment with radiotherapy, however, it does seem to prevent patients from reaching higher degrees of xerostomia taking into account salivary flow measures.


Subject(s)
Dental Caries , Head and Neck Neoplasms , Xerostomia , Cross-Sectional Studies , Female , Head and Neck Neoplasms/radiotherapy , Humans , Male , Middle Aged , Quality of Life , Xerostomia/etiology
6.
Braz. j. med. biol. res ; 53(1): e8621, Jan. 2020. tab, graf
Article in English | LILACS | ID: biblio-1055482

ABSTRACT

The use of specially designed wound dressings could be an important alternative to facilitate the healing process of wounds in the hyperglycemic state. Biocompatible dressings combining chitosan and alginate can speed up wound healing by modulating the inflammatory phase, stimulating fibroblast proliferation, and aiding in remodeling phases. However, this biomaterial has not yet been explored in chronic and acute lesions of diabetic patients. The aim of this study was to evaluate the effect of topical treatment with a chitosan-alginate membrane on acute skin wounds of hyperglycemic mice. Diabetes mellitus was induced by streptozotocin (60 mg · kg-1 · day-1 for 5 days, intraperitoneally) and the cutaneous wound was performed by removing the epidermis using a surgical punch. The results showed that after 10 days of treatment the chitosan and alginate membrane (CAM) group exhibited better organization of collagen fibers. High concentrations of interleukin (IL)-1α, IL-1β, granulocyte colony-stimulating factor (G-CSF), and tumor necrosis factor-alpha (TNF-α) were detected in the first and second days of treatment. G-CSF and TNF-α level decreased after 5 days, as well as the concentrations of TNF-α and IL-10 compared with the control group (CG). In this study, the inflammatory phase of cutaneous lesions of hyperglycemic mice was modulated by the use of CAM, mostly regarding the cytokines IL-1α, IL-1β, TNF-α, G-CSF, and IL-10, resulting in better collagen III deposition. However, further studies are needed to better understand the healing stages associated with CAM use.


Subject(s)
Animals , Male , Rabbits , Bandages , Wound Healing/drug effects , Chitosan/administration & dosage , Cell Proliferation/drug effects , Diabetes Mellitus, Experimental/physiopathology , Alginates/administration & dosage , Time Factors , Biocompatible Materials/administration & dosage , Biomarkers/blood , Collagen/drug effects , Inflammation/prevention & control , Mice, Inbred C57BL
7.
Braz J Med Biol Res ; 53(1): e8621, 2020.
Article in English | MEDLINE | ID: mdl-31859909

ABSTRACT

The use of specially designed wound dressings could be an important alternative to facilitate the healing process of wounds in the hyperglycemic state. Biocompatible dressings combining chitosan and alginate can speed up wound healing by modulating the inflammatory phase, stimulating fibroblast proliferation, and aiding in remodeling phases. However, this biomaterial has not yet been explored in chronic and acute lesions of diabetic patients. The aim of this study was to evaluate the effect of topical treatment with a chitosan-alginate membrane on acute skin wounds of hyperglycemic mice. Diabetes mellitus was induced by streptozotocin (60 mg · kg-1 · day-1 for 5 days, intraperitoneally) and the cutaneous wound was performed by removing the epidermis using a surgical punch. The results showed that after 10 days of treatment the chitosan and alginate membrane (CAM) group exhibited better organization of collagen fibers. High concentrations of interleukin (IL)-1α, IL-1ß, granulocyte colony-stimulating factor (G-CSF), and tumor necrosis factor-alpha (TNF-α) were detected in the first and second days of treatment. G-CSF and TNF-α level decreased after 5 days, as well as the concentrations of TNF-α and IL-10 compared with the control group (CG). In this study, the inflammatory phase of cutaneous lesions of hyperglycemic mice was modulated by the use of CAM, mostly regarding the cytokines IL-1α, IL-1ß, TNF-α, G-CSF, and IL-10, resulting in better collagen III deposition. However, further studies are needed to better understand the healing stages associated with CAM use.


Subject(s)
Alginates/administration & dosage , Bandages , Cell Proliferation/drug effects , Chitosan/administration & dosage , Diabetes Mellitus, Experimental/physiopathology , Wound Healing/drug effects , Animals , Biocompatible Materials/administration & dosage , Biomarkers/blood , Collagen/drug effects , Inflammation/prevention & control , Male , Mice , Mice, Inbred C57BL , Time Factors
8.
Rev Esp Anestesiol Reanim (Engl Ed) ; 66(8): 447-450, 2019 Oct.
Article in English, Spanish | MEDLINE | ID: mdl-31395405

ABSTRACT

Trigeminal neuralgia (TN) is a severe and often underestimated facial pain that affects quality of life. Pharmacological treatment is insufficient for pain control in 30% of cases and, although intervention techniques may be effective, there is a possibility of relapse and associated complications. The second division of the trigeminal nerve (V2) runs through the sphenopalatine ganglion (SPG), which is anatomically accessible to blocking due to its superficial location in the nasal cavity. We report a clinical case of a patient with uncontrolled V2 TN that was put on ambulatory self-administered SPG block with nasal swabs soaked in 0.75% ropivacaine. In the follow-up visits, we confirmed that this adjuvant treatment provided a significant pain relief over 24hours with a decrease in the number of exacerbations.


Subject(s)
Anesthetics, Local/administration & dosage , Curettage/adverse effects , Facial Pain/therapy , Intraoperative Complications/therapy , Mandibular Nerve Injuries/therapy , Maxillary Sinus/surgery , Pain, Postoperative/therapy , Ropivacaine/administration & dosage , Sphenopalatine Ganglion Block/methods , Trigeminal Neuralgia/therapy , Administration, Intranasal , Aged , Analgesics/therapeutic use , Antidepressive Agents/therapeutic use , Combined Modality Therapy , Facial Pain/drug therapy , Facial Pain/etiology , Humans , Instillation, Drug , Intraoperative Complications/drug therapy , Intraoperative Complications/etiology , Intraoperative Complications/physiopathology , Male , Mandibular Nerve Injuries/drug therapy , Mandibular Nerve Injuries/etiology , Mandibular Nerve Injuries/physiopathology , Pain, Postoperative/drug therapy , Pain, Postoperative/etiology , Self Administration , Trigeminal Neuralgia/drug therapy , Trigeminal Neuralgia/etiology
9.
Obes Sci Pract ; 2(2): 210-214, 2016 06.
Article in English | MEDLINE | ID: mdl-27840691

ABSTRACT

BACKGROUND: Obesity has emerged as major public health problem leading to increased morbidity and mortality. Epidemiological studies indicate that in many regions of the world, children and teenagers are increasingly affected by obesity, which contributes for a pessimistic projection for the near future. Maternal obesity has been implicated in metabolic disorders of the offspring, but there are no biological markers that can be detected early on life that predict the development of obesity in the offspring. OBJECTIVE: To evaluate the expression of inflammatory markers in the umbilical cord blood of babies of mothers with obesity/overweight, and correlate these markers with the body weight at age 9 months. METHODS: Anthropometric data of mothers and babies were obtained during prenatal evaluation, at birth and 9 months after birth. Cord blood was collected during delivery of 54 babies from mothers with obesity/overweight and of 50 babies from lean mothers. Tumour necrosis factor-alpha (TNF-α), transforming growth factor 1 beta, monocyte chemoattractant protein-1 and 2 (MCP-1/MCP-2) were determined in serum samples using enzyme-linked immunosorbent assay methods. Correlations were evaluated using the Spearman correlation coefficient, and comparisons were evaluated using the non-parametric Mann-Whitney U-test. RESULTS: Cord blood TNF-α was positively correlated with maternal body mass index. There was an inverse correlation between cord blood transforming growth factor 1 beta and baby body weight at birth. There was no biological marker that predicted body weight at age 9 months. CONCLUSION: Although we have not found a biological marker to predict increased body weight at 9 months of age, the study shows that maternal obesity exposes the baby to higher TNF-α level in the early stages of life, and this can affect metabolic and inflammatory parameters during adulthood.

10.
Biol Res Nurs ; 18(2): 181-92, 2016 Mar.
Article in English | MEDLINE | ID: mdl-26111834

ABSTRACT

The healing process is complex in diabetic wounds, and the healing mechanism of burn wounds is different from that of incisional or excisional wounds. Data from our previous study indicated that topical insulin cream reduced wound closure time in diabetic rats. Our aim was to investigate the effect of topical insulin cream on wound healing following second-degree burns in control and diabetic rats. Rats were divided into four groups: control (nondiabetic) rats treated with placebo (CP), control (nondiabetic) rats treated with topical insulin cream (CI), diabetic rats treated with placebo (DP), and diabetic rats treated with topical insulin cream (DI). The wounds were assessed at 4 time points (1, 7, 14, and 26 days) post-wounding for morphometric analysis of wound sections stained with hematoxylin/eosin, α-smooth muscle actin, and Picrosirius red to evaluate general aspects of the wound, inflammatory infiltrate, blood vessels, and Types I and III collagen fibers. Histological analysis showed that topical insulin cream increased the inflammatory cell infiltrate in the DI group (at 7 and 14 days postburn, p < .05) and blood vessels (at 14 days postburn, p < .05) to levels similar to those of groups CP and CI. Wounds treated with topical insulin cream (CI and DI groups) showed significantly stronger staining for fibrillar collagen than wounds of the DP group. The use of topical insulin may reduce the duration of the inflammatory phase; improve wound reepithelialization, tissue granulation, and wound contraction; and increase collagen deposition in second-degree burns in healthy and diabetic animals.


Subject(s)
Burns/drug therapy , Diabetes Mellitus, Experimental/physiopathology , Granulation Tissue/drug effects , Insulin/administration & dosage , Skin Cream/administration & dosage , Wound Healing/drug effects , Administration, Topical , Animals , Male , Rats , Rats, Wistar
11.
Health Policy ; 56(2): 99-110, 2001 May.
Article in English | MEDLINE | ID: mdl-11275300

ABSTRACT

Opioids are not always available in many developing countries, including those in Latin America. In this study we analyzed the national laws on opioids and other controlled substances from Argentina, Colombia, Costa Rica, Peru, Mexico, and the state of Texas, according to the principles set by the World Health Organization (WHO) and the International Narcotics Control Board (INCB), as well as to the presence of over-regulations regarding their medical and scientific use. The six main principles outlined by WHO and INCB for opioid availability were analyzed by using a total of 17 criteria as shown in Table 3. The result scores ranged from 17/17 (full compliance with all criteria) to 0/17 (non-compliance). Results showed that with the exception of the state of Texas 16/17 (94%), the countries failed to adequately meet the INCB and WHO criteria: Argentina: 7/17 (41%); Colombia: 9 /17 (53%); Costa Rica: 9/17 (53%); Mexico: 4/17 (24%); and Peru: 7/17 (41%). In all 5 Latin American countries, national laws and regulations imposed limits on the number of days allowed for prescription, the potency of the dosage, and the number of doses allowed per day. In all cases, including Texas, there was confusion on the meaning and utilization of the terms physical dependence, psychological dependence, addiction, tolerance and abuse. In total, combining all cases, only 51% of the criteria were met. Additionally, all laws and regulations, especially in Argentina, include over regulations and statements that may further interfere with patient access to opioids. The prescription criteria were fully met by the state of Texas and all five countries. These results indicate that there is need to revise the existing laws and regulations in countries with opioid availability problems, and identify the potential barriers, which may be playing a significant role in the access to adequate treatment. Such review seeks to carefully consider all possible criteria, since partial resolution of legislative articles will not result in increased opioid availability.


Subject(s)
Drug and Narcotic Control/legislation & jurisprudence , Health Policy , Narcotics/supply & distribution , Palliative Care/legislation & jurisprudence , World Health Organization , Argentina , Colombia , Costa Rica , Developing Countries , Humans , Mexico , Peru , Texas
12.
Curr Eye Res ; 21(5): 833-42, 2000 Nov.
Article in English | MEDLINE | ID: mdl-11262604

ABSTRACT

PURPOSE: Insulin has been acknowledged as a mediator of several physiological events in lacrimal and salivary glands. We investigated the presence of insulin receptors and of insulin-induced autophosphorylation of the insulin receptor and activation of elements involved in the early steps of insulin signaling in lacrimal and salivary glands of rats. METHODS: Lacrimal and salivary glands of Wistar rats were removed and processed for immunohistochemistry using anti-insulin receptor and anti-IGF-1 receptor antibodies. The activation of insulin receptors following insulin treatment, and the involvement of insulin receptor substrates-1 and -2, Shc, JAK-2 and STAT-1, were analyzed by immunoprecipitation, followed by SDS-PAGE and immunoblotting of rat lacrimal and salivary glands after exposure to insulin. RESULTS: Insulin and IGF-1 receptors were present in rat lacrimal and salivary glands and were located predominantly in the cytoplasm and plasma membrane. Functional studies demonstrated that insulin induced a dose-dependent phosphorylation of the insulin receptor, IGF-1R, insulin receptor substrates-1 and -2, Shc, and STAT-1. In rats with streptozotocin-induced diabetes mellitus there was a significant reduction in insulin-induced insulin receptor and STAT-1 phosphorylation in the lacrimal gland but not in the salivary gland; there was no influence on Shc phosphorylation in either tissue. CONCLUSIONS: The present results indicate that insulin and IGF-1 receptors are expressed in lacrimal and salivary glands, and that insulin can induce the phosphorylation of its receptor and activate elements involved in the early steps of insulin signaling in both tissues.


Subject(s)
Adaptor Proteins, Signal Transducing , Adaptor Proteins, Vesicular Transport , Insulin/physiology , Lacrimal Apparatus/metabolism , Proto-Oncogene Proteins , Receptor, IGF Type 1/metabolism , Receptor, Insulin/metabolism , Salivary Glands/metabolism , Signal Transduction , Animals , DNA-Binding Proteins/metabolism , Diabetes Mellitus, Experimental/metabolism , Dose-Response Relationship, Drug , Electrophoresis, Polyacrylamide Gel , Immunoblotting , Insulin/pharmacology , Insulin Receptor Substrate Proteins , Intracellular Signaling Peptides and Proteins , Janus Kinase 2 , Lacrimal Apparatus/drug effects , Male , Phosphoproteins/metabolism , Phosphorylation , Precipitin Tests , Protein-Tyrosine Kinases/metabolism , Proteins/metabolism , Rats , Rats, Wistar , STAT1 Transcription Factor , Salivary Glands/drug effects , Shc Signaling Adaptor Proteins , Src Homology 2 Domain-Containing, Transforming Protein 1 , Trans-Activators/metabolism , Tyrosine/metabolism
13.
Braz. j. med. biol. res ; 31(11): 1409-13, Nov. 1998. ilus
Article in English | LILACS | ID: lil-224474

ABSTRACT

Insulin stimulates the tyrosine kinase activity of its receptor resulting in the phosphorylation of its cytosolic substrate, insulin receptor substrate-1 (IRS-1) which, in turn, associates with proteins containing SH2 domains. It has been shown that IRS-1 associates with the tyrosine phosphatase SHPTP2 in cell cultures. While the effect of the IRS-1/SHPTP2 association on insulin signal transduction is not completely known, this association may dephosphorylate IRS-1 and may play a critical role in the mitogenic actions of insulin. However, there is no physiological demonstration of this pathway of insulin action in animal tissues. In the present study we investigated the ability of insulin to induce association between IRS-1 and SHPTP2 in liver and muscle of intact rats, by co-immunoprecipitation with anti-IRS-1 antibody and anti-SHPTP2 antibody. In both tissues there was an increase in IRS-1 association with SHPTP2 after insulin stimulation. This association occurred when IRS-1 had the highest level of tyrosine phosphorylation and the decrease in this association was more rapid than the decrease in IRS-1 phosphorylation levels. The data provide evidence against the participation of SHPTP2 in IRS-1 dephosphorylation in rat tissues, and suggest that the insulin signal transduction pathway in rat tissues is related mainly to the mitogenic effects of the hormone.


Subject(s)
Animals , Rats , Liver/enzymology , Muscles/enzymology , Phosphoproteins , Protein Tyrosine Phosphatases , Receptor, Insulin
14.
Braz J Med Biol Res ; 31(5): 697-703, 1998 May.
Article in English | MEDLINE | ID: mdl-9698777

ABSTRACT

The present study examines the effect of concanavalin A (Con A) on the blood insulin and glucose levels of rats. Male and female rats treated with Con A (62.5-500 micrograms/kg) for three days showed a dose- and time-dependent hyperinsulinemia that lasted more than 48 h. Male rats were more sensitive to Con A. Thus, 6 h after treatment with Con A the circulating insulin levels in male rats had increased by 85% (control: 10.2 +/- 0.9 mU/l and Con A-treated: 18.8 +/- 1 mU/l) compared to only 38% (control: 7.5 +/- 0.2 mU/l; Con A-treated: 10.3 +/- mU/l) in females. An identical response was seen after 12 h. Con A (250 micrograms/kg) produced time-dependent hypoglycemia in both sexes but more pronounced in males. There was no correlation between the hypoglycemia and hyperinsulinemia described above. The Con A-induced hyperinsulinemia in rats of both sexes was abolished in gonadectomized animals (intact males: +101 +/- 17% vs orchiectomized males: -5 +/- 3%; intact females: +86 +/- 23% vs ovariectomized females: -18 +/- 7.2%). Pretreating intact male and female rats with human chorionic gonadotropin also significantly inhibited the Con A-induced hyperinsulinemia. Estradiol (10 micrograms/kg,i.m.) significantly blocked the Con A-induced increase in circulating insulin in male rats (101 +/- 17% for controls vs 32 +/- 5.3% for estradiol-treated animals, P < 0.05) while testosterone (10 mg/kg, i.m.) had no similar effect on intact female rats. Pretreating Con A-injected rats with opioid antagonists such as naloxone (1 mg/kg, s.c.) and naltrexone (5 mg/kg, s.c.) blocked the hyperinsulinemia produced by the lectin in males (control: +101 +/- 17% vs naloxone-treated: +5 +/- 14%, or naltrexone-treated: -23 +/- 4.5%) and females (control: +86 +/- 23% vs naloxone-treated: +21 +/- 20%, or naltrexone-treated: -18 +/- 11%). These results demonstrate that Con A increases the levels of circulating insulin in rats and that this response is opioid-dependent and hormonally regulated.


Subject(s)
Concanavalin A/pharmacology , Hormones/pharmacology , Hyperinsulinism/chemically induced , Narcotic Antagonists/pharmacology , Animals , Blood Glucose/analysis , Castration , Female , Insulin/blood , Male , Rats , Rats, Wistar , Time Factors
15.
Braz. j. med. biol. res ; 31(5): 697-703, May 1998. tab, graf
Article in English | LILACS | ID: lil-212410

ABSTRACT

The present study examines the effect of concanavalin A (Con A) on the blood insulin and glucose levels of rats. Male and female rats treated with Con A (62.5-500 mug/kg) for three days showed a dose-and time-dependent hyperinsulinemia that lasted more than 48 h. Male rats were more sensitive to Con A. Thus, 6 h after treatment with Con A the circulating insulin levels in male rats had increased by 85 percent (control: 10.2 + 0.9 mU/l and Con A-treated: 18.8 + 1 mU/l) compared to only 38 percent (control: 7.5 + 0.2 mU/l; Con A-treated: 10.3 + mU/l) in females. An identical response was seen after 12 h. Con A (250 mug/kg) produced time-dependent hypoglycemia in both sexes but more pronounced in males. There was no correlation between the hypoglycemia and hyperinsulinemia described above. The Con A-induced hyperinsulinemia in rats of both sexes was abolished in gonadectomized animals (intact males: +101 + 17 percent vs orchiectomized males: -5 + 3 percent; intact females: +86 + 23 percent vs ovariectomized females: -18 + 7.2 percent). Pretreating intact male and female rats with human chorionic gonadotropin also significantly inhibited the Con A-induced hyperinsulinemia. Estradiol (10 mug/kg, im) significantly blocked the Con A-induced increase in circulating insulin in male rats (101 + 17 percent for controls vs 32 + 5.3 percent for estradiol-treated animals, P<0.05) while testosterone (10 mg/kg, im) had no similar effect on intact female rats. Pretreating Con A-injected rats with opioid antagonists such as naloxone (1 mg/kg, sc) and naltrexone (5 mg/kg, sc) blocked the hyperinsulinemia produced by the lectin in males (control: +101 + 17 percent vs naloxone-treated: +5 + 14 percent, or naltrexone-treated: -23 + 45 percent) and females (control: +86 + 23 por cent vs naloxone-treated: +21 + 20 percent, or naltrexone-treated: -18 + 11 percent). These results demonstrate that Con A increases the levels of circulating insulin in rats and that this response is opioid-dependent and hormonally regulated.


Subject(s)
Animals , Male , Female , Rats , Concanavalin A/adverse effects , Hormones/pharmacology , Hyperinsulinism/chemically induced , Narcotic Antagonists/pharmacology , Blood Glucose/analysis , Castration , Insulin/blood , Rats, Wistar , Time Factors
16.
Braz J Med Biol Res ; 31(11): 1409-13, 1998 Nov.
Article in English | MEDLINE | ID: mdl-9921276

ABSTRACT

Insulin stimulates the tyrosine kinase activity of its receptor resulting in the phosphorylation of its cytosolic substrate, insulin receptor substrate-1 (IRS-1) which, in turn, associates with proteins containing SH2 domains. It has been shown that IRS-1 associates with the tyrosine phosphatase SHPTP2 in cell cultures. While the effect of the IRS-1/SHPTP2 association on insulin signal transduction is not completely known, this association may dephosphorylate IRS-1 and may play a critical role in the mitogenic actions of insulin. However, there is no physiological demonstration of this pathway of insulin action in animal tissues. In the present study we investigated the ability of insulin to induce association between IRS-1 and SHPTP2 in liver and muscle of intact rats, by co-immunoprecipitation with anti-IRS-1 antibody and anti-SHPTP2 antibody. In both tissues there was an increase in IRS-1 association with SHPTP2 after insulin stimulation. This association occurred when IRS-1 had the highest level of tyrosine phosphorylation and the decrease in this association was more rapid than the decrease in IRS-1 phosphorylation levels. The data provide evidence against the participation of SHPTP2 in IRS-1 dephosphorylation in rat tissues, and suggest that the insulin signal transduction pathway in rat tissues is related mainly to the mitogenic effects of the hormone.


Subject(s)
Liver/enzymology , Muscles/enzymology , Phosphoproteins/physiology , Protein Tyrosine Phosphatases/physiology , Receptor, Insulin/physiology , Animals , Insulin Receptor Substrate Proteins , Intracellular Signaling Peptides and Proteins , Protein Tyrosine Phosphatase, Non-Receptor Type 11 , Protein Tyrosine Phosphatase, Non-Receptor Type 6 , Rats
19.
Stain Technol ; 53(2): 91-4, 1978 Mar.
Article in English | MEDLINE | ID: mdl-694955

ABSTRACT

The classical sulfuric acid method for the histochemical detection of carotenoids has been adapted to give a reliable cytological localization of these compounds in fish chromatophores. This procedure consists mainly in fixing skin fragments in glutaraldehyde and dehydrating in a 50% solution of glycerin followed by exposure to air. It is essential that the preparation permit direct contact of the sulfuric acid with the pigment cells. Under these conditions, carotenoid containing cells stain green or blue. When associated with the extraction of the carotenoids by acetone, the procedure permits the distinction between pterin and carotenoid in fish chromatophores.


Subject(s)
Carotenoids/isolation & purification , Chromatophores/analysis , Fishes/anatomy & histology , Histocytochemistry/methods , Pterins/isolation & purification , Skin/ultrastructure , Acetone , Animals , Sulfuric Acids
SELECTION OF CITATIONS
SEARCH DETAIL
...