Polimorfismo PRO12ALA del gen PPARy2, ALA54THR del gen FABP2 y polimorfismos del gen de alipoproteina E en habitantes del sector los eucaliptos de la parroquia san juan, munisipio libertador / PRO12ALA polymorhism of the PPARy2 gene, ALA54THR polymorphism of the FABP2 gene and polymorphisms of the apolipoprotein E gene in the population of Eucapliptos of the parroquia san jua, municipio libertador

Las enfermedades cardiovasculares y el síndrome metabólico son patologías que afectan a gran parte de la población mundial, de etiología poligénica y multifactorial, resultado de la interacción entre factores genéticos, ambientales, sociales y culturales. Los principales genes candidatos a estudiar son aquellos relacionados con la regulación de la homeostasis de la glucosa, del metabolismo lipídico y/o de la secreción y acción de la insulina, como son el gen de los Receptores de los Proliferadores Perixosomales Activados gamma 2 (PPARγ2), la Proteína Enlazante de Ácidos Grasos Intestinal (FABP2) y la Apolipoproteína E (ApoE). Evaluar la relación entre los polimorfismos Pro12Ala del gen PPARγ2, Ala54Thr del gen FABP2 y del gen de ApoE en habitantes del Sector “Los Eucaliptos” de la Parroquia San Juan. 308 individuos de dicha comunidad, 98 hombres y 210 mujeres, clasificados en hipercolesterolémicos, hipertrigliceridémicos, resistentes a la insulina y controles de acuerdo a sus niveles de colesterol total, triglicéridos e índice HOMA. Extracción de 10 mL de sangre venosa para la determinación de química sanguínea y extracción de ADN, amplificación mediante PCR de un fragmento de 102pb del gen de PPARγ2, uno de 180pb del gen de FABP2 y otro de 244pb del gen de ApoE, y posterior RFLP. Se encontró una frecuencia alélica de 0,91 para el alelo Pro y 0,09 para el Ala del gen de PPARγ2; 0,70 para el alelo Ala del gen FABP2 y 0,30 para el Thr, mientras que para los alelos del gen de ApoE la frecuencia fue de ε2=0,05, ε3=0,80 y ε4=0,15. Se encontró relación entre el alelo ε4 de ApoE y la hipercolesterolemia, además del alelo ε2 como factor protector ante el desarrollo de hipercolesterolemia, hipertrigliceridemia y resistencia a la insulina, no encontrándose asociación alguna entre los polimorfismos de los restantes genes y las patologías mencionadas.

Cardiovascular disease and metabolic syndrome are diseases that affect worldwide, with multiple genetic and environmental components contributing to susceptibility. The main candidate genes to study are those related to the regulation of glucose homeostasis, lipid metabolism, insulin secretion and action and obesity, these include the genes for Peroxisome proliferator-activated receptor gamma 2 (PPARγ2), fatty acid-binding protein 2 (FABP2) and Apolipoprotein E (Apo E). The aim of this study was to investigate the relationship between polymorphisms of Pro12Ala PPARγ2 gene, Ala54Thr FABP2 gene and the ApoE gene in residents from the “The Eucaliptus” of the “Parroquia San Juan”. 308 subjects, 98 men and 210 women, classified as hypercholesterolemic, hypertriglyceridemic, insulin resistant and controls according to their levels of total cholesterol, triglycerides and HOMA index. Extraction of 10 mL whole blood for determination of chemistry and DNA extraction, PCR amplification of a 102 bp fragment PPARγ2 gene, a 180 bp FABP2 gene and a 244 bp of ApoE gene, and subsequent RFLP. An allele frequency for allele Pro 0.91 and 0.09 for gene PPARγ2 Ala and 0.70 for the allele of the gene FABP2 Ala and 0.30 for Thr, while for the different alleles of ApoE gene frequency was ε2=0.05, ε3=0.80 and ε4=0.15. We found a relationship between the ApoE ε4 allele and hypercholesterolemia, in the other hand, Apo E ε2 allele was found as a protective factor against the development of hypercholesterolemia, hypertriglyceridemia and insulin resistance, we did not found association between polymorphisms of the other genes and the pathologies mentioned above.

Effect of temperature on the potency & pharmacological action of insulin.

Background & objectives: Since proper storage of insulin is necessary for its action, the present study was undertaken to determine the extent to which improper temperature storage conditions could have contributed to the potency of the three insulin formulations tested. Methods: Two human insulin formulations (regular and biphasic) from three different manufacturers were stored at 5 different temperatures. In vitro potency of insulin was determined by high performance liquid chromatography on every seventh day for a period of 28 days. For the in vivo study, insulin tolerance test was done by injecting human regular insulin intraperitoneally to rabbits on the 25th day of storage. Blood glucose was determined at 0, 15, 30 and 60 min after insulin injection using glucometer. Results: Storage at 32 and 37ºC showed 14-18 per cent decrease in potency of insulin in both the formulations on 28th day for all the three brands. Also the rabbits receiving insulin stored in 32 and 37ºC did not show a significant decrease in blood sugar level when compared to those receiving insulin stored at 5ºC. Interpretation & conclusions: Improper storage of insulin decreases the potency and hence the pharmacological action of insulin. Patients should be educated on the proper methods of storage, and free supplies of insulin for more than two weeks use should not be dispensed.

Análise quantitativa das células das ilhotas pancreáticas de ratos pinealectomizados / Quantitative analysis of pancreatic islet cells of pinealectomised rats

Foi verificada a influência da glândula pineal em relação à análise quantitativa das células α, β e δ através de estudo imuno-histoquímico. Vinte ratos Wistar foram distribuídos em 2 grupos (grupo controle - grupo pinealectomizados). Os animais foram sacrificados 70 dias após a cirurgia. Amostras de pâncreas foram coradas com anticorpos monoclonais antiinsulina, antiglucagon e antisomatostatina. Foram contadas as células de cinco ilhotas de cada segmento. O número de células positivas para insulina nos ratos normais variou de 91 a 777 (312,5 ± 203,8) e nos pinealectomizados de 81 a 903 (524,4 ± 300,3); em relação ao glucagon variou nos normais de 83 a 326 (164,6 ± 95,4) e nos pinealectomizados de 95 a 287 (188,8 ± 78,4); em relação à somatostatina variou nos normais de 13 a 65 (35,4 ± 20,9) e nos pinealectomizados de 11 a 65 (29,7 ± 18,4). O número médio de células positivas para insulina nos animais pinealectomizados apresentou-se superior ao dos normais, mas essa superioridade não foi estatisticamente significante (p = 0,08). Estes resultados demonstram que a pineal parece exercer influência no pâncreas endócrino e corroboram estudos prévios.

The influence of the pineal gland on pancreatic islet with respect to a quantitative analysis of α, β and δ cells by immunohistochemistry was verified. Twenty Wistar rats was divided in two groups (control group - pinealectomysed group). The animals were sacrificed 70 days after surgery. Fragments of pancreas segments were stained with anti-insulin, anti-glucagon and antisomatostatin monoclonal antibodies. The cells of five islets were counted in each segments. The number of insulin-positive cells ranged from 91 to 777 (312,5 ± 203,8) in normal rats and from 81to 903 (524,4 ± 300,3) in pinealectomysed rats; glucagon-positive cells ranged from 83 to 326 - 164,6 ± 95,4 - (normals) and from 95 to 287 - 188,8 ± 78,4 - (pinealectomysed); somatostatin-positive cells ranged from 13 to 65 - 35,4 ± 20,9 - (normals) and from 11 to 65 - 29,7 ± 18,4 - (pinealectomysed). The mean number of insulin-positive cells was higher in pinealectomysed animals than in normal animals but not significantly (p = 0.08). These results indicate that the pineal gland seems to have an influence on endocrine pancreas and support previous studies.

Decreased basal and acute insulin-stimulated effect on the uptake of glucose and amino acid in vitro by thyroid glands from streptozotocin-diabetic rats

Since experimental diabetes in rats and mice is associated with impairment of several aspects of thyroid function, we determined glucose and amino acid uptake in vitro by isolated thyroid glands from normal and streptozotocin-diabetic rats. Adult male Wistar rats weighing 150-200 g were used. Diabetes was induced by intraperitoneal injection streptozotocin (STZ, 65 mg/kg body weight) and after five days only rats with blood glucose levels higher than 250 mg/dl were used. The thyroid glands were preincubated in Krebs-Ringer bicarbonate buffer in the presence or absence of insulin (0.7 nM to 7 muM) for 90 min and then incubated with the same concentration of the hormone or its vehicle plus 0.2 muCi of [l-l4C]-2-deoxy-D-glucose ([l4C]DG) or [l4C] methylaminoisobutyric acid ([l4C]MeAIB) for 15 to 180 min. The uptake of [l4C]DG or [l4C]MeAIB by the thyroid glands of normal rats increased as a function of incubation time, and the presence of insulin (7 muM) induced a significant increase of labelled DG from 3.30 ñ 0.11 to 4.16 ñ O.12 and of labelled MeAIB from 1.79 ñ 0.06 to 3.10 ñ 0.17 tissue/medium ratio (TIM) after 45 min of incubation. The lowest concentration of insulin that increased both [l4C]DG and [l4C]MeAIB transport was 7 nM. Thyroid glands from STZ rats exhibited lower basal values of [l4C]DG (4.03 ñ 0.11 T/M) or [l4C]MeAIB uptake (1.05 ñ 0.05 T/M) than glands from normal rats (4.62 ñ 0.13 and 1.70 ñ 0.O8 T/M, respectively). Insulin produced a stimulatory effect on the transport of both substrates in STZ rats. However, the maximals stimulating concentration of the hormone did not restore[l4C]DG and [l4C)MeAIB uptake to control values (4.89 + O.17 in STZ rats versus 5.44 ñ 0.17 T/M in controls for [l4C]DG, and 1.51 ñ 0.11 in STZ rats versus 2.19 ñ 0.10 T/M in controls for [l4C]MeAIB). These results indicate that insulin exerts a direct action on the thyroid gland, and its absence or reduction affects thyroid metabolism, contributing, at least in part, to the abnormality in thyroid function associated with diabetes mellitus.

Hipoglicemia associada a tumor extrapancreático / Hypoglycemya associated with extra-pancreatic tumor

Os autores descrevem o caso de uma mulher de 51 anos, portadora de massa torácica extrapulmonar, que apresentou episódios de hipoglicemia sintomática dejejum. Esse quadro reverteu após a retirada cirúrgica de um mesotelioma pleural benigno, que pesava 1.800g. Sao discutidos os mecanismos de hipoglicemia tumoral extrapancreática em face de níveis indetectáveis de insulina, como em nosso caso.