Browsing by Subject "Insulin"

Now showing 1 - 12 of 12
  • Thumbnail Image
    Publication
    Open Access
    A quantitative description of the insulin-induced ultrastructural changes in newborn rat hepatocytes
    (Murcia : F. Hernández, 1993) Maintas, D.B.; Kotoulas, Othon B.; Kotoulas, Angeliki O.
    The effects of insulin on the ultrastructure of newborn rat hepatocytes were systernatically quantified at satisfactory statistical significance. Insulin prevented the normal postnatal increase in the total volume of lysosomes and the breakdown of glycogen inside these organelles. The lysosomal glycogen-hydrolysing enzyme, acid alpha 1,4 glucosidase was inhibited by the hormone. Insulin also prevented the normal postnatal increase in the total volume of peroxisomes, especially of the crystalloid core-devoid type. The hormone produced an increase in the area of cell membrane, due to the forrnation of many irregular folds of the cell surface. These results constitute good evidence for participation of lysosomes and peroxisomes in the overall glycogen degradation and or gluconeogenesis in the newborn rat hepatocytes.
  • Thumbnail Image
    Publication
    Open Access
    Conocimiento actual de las hormonas reguladoras de la ingestión de alimentos en la especie porcina
    (Murcia: Servicio de Publicaciones de la Universidad de Murcia, 2013) Martínez Subiela, Silvia; Campos, C.; Madrid Sánchez, Josefa; Cerón Madrigal, José Joaquín; Orengo Femenia, Juan; Tvarijonaviciute, Asta; Valera, L.; Hernández, F.; Medicina y Cirugía Animal
    Este trabajo es una revisión de los estudios realizados en la especie porcina sobre el comportamiento de la insulina, leptina y grelina, y su implicación en la regulación de la ingestión de alimentos. Desde el punto de vista productivo es de gran interés por constituir una fuente de información importante para conocer el estado metabólico y energético del animal. Los animales, durante su crecimiento y a lo largo de su vida productiva, pasan por diferentes etapas con necesidades específicas que deben ser cubiertas mediante el aporte de nutrientes a través de la alimentación. La salud de los animales dependen de la habilidad del cuerpo para regular de forma adecuada el equilibrio entre las necesidades y los aportes, y este equilibrio está regulado por del sistema nervioso central mediante señales neuronales o la liberación de hormonas. Las hormonas implicadas en la ingestión de alimentos, es decir, aquellas que ejercen un papel regulador sobre el apetito o la saciedad, pueden clasificarse en orexigénica o anorexigénicas según su capacidad de estimular o inhibir, respectivamente, el consumo de alimentos. La grelina, también llamada hormona del hambre, es la principal hormona orexigénica, es producida principalmente en el estómago en respuesta al hambre y la inanición. Durante el ayuno, o en estados energéticos insuficientes eleva sus niveles en sangre y tras la alimentación recupera los niveles basales. Entre las hormonas anorexigénicas destaca la leptina secretada principalmente por las células del tejido adiposo, cuya función primordial es la regulación de la ingestión de alimentos y del gasto energético, a largo plazo, para mantener las reservas corporales, de manera que, cuando un individuo está en balance energético positivo los niveles de leptina aumentan presentando un estado de saciedad que provoca la disminución en el consumo alimentos y/o apetito. Además, tras la ingestión de alimento, se secreta insulina, que es la principal hormona encargada de regular la glucemia y esta implicada en la regulación del apetito por interactuar con otras hormonas. Aunque estas hormonas han sido ampliamente estudiadas en la especie humana y roedores, es de esperar que en las próximas décadas su estudio se extienda a todos las especies domésticas.
  • Thumbnail Image
    Publication
    Open Access
    Evaluation of CART-, glucagon-, and insulinimmunoreactive cells in the pancreas of an experimental rat model of unilateral renal artery stenosis
    (F. Hernández y Juan F. Madrid. Universidad de Murcia: Departamento de Biología Celular e Histología, 2015) Kasacka, I.; Janiuk, I.; Piotrowska, Z.
    Hypertension is one of the most frequently occurring diseases worldwide. Approximately 10% of the population with hypertension reveal the secondary type of hypertension. The aim of this study was to evaluate the cells containing CART, insulin and glucagon in the pancreas of rats with renovascular hypertension. An experimental model of hypertension in rats according to Goldblatt (2K1C model of hypertension) was used in the study. The experimental material (pancreas) was collected in the 6th week of the study. Cells containing CART, insulin and glucagon were evaluated using immunohistochemical and morphometric methods. Pancreatic islet cells were evaluated based on the number and intensity of staining. The investigation showed an increase in the number and immunoreactivity of CART containing cells, 6 weeks after partial unilateral ligation of the renal artery. There was a significant decrease in the number of glucagon-IR cells. Although intensity of staining these cells did not change. No differences were observed in the number and staining affinity of insulin-containing cells. On the basis of the study it can be stated that the endocrine system of pancreas undergoes changes in the course of renovascular hypertension. This may affect the production of hormones and contribute to the development of possible hypertension complications.
  • Thumbnail Image
    Publication
    Open Access
    Histopathological evaluation of insulin-DMSO formula designed for direct nose-to-brain delivery
    (Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2022) Maher, Mustafa A.; Kandeel, Wafaa A.; Hammam, Olfat A.; Attia, Yasmeen M.; Mahmoud, Soheir; Salah, Mohamed
    The combination of insulin and DMSO is a patented (Publication No US8987199B2), noninvasive, pharmaceutically strategized preparation for direct noseto-brain delivery (DN2BD) suggested for the treatment of Alzheimer’s disease (AD). Although its main ingredients have been individually researched, no histopathological investigations have been conducted to address this combination effect on the CNS and nasal tissues in animals. The present work was, therefore, designed to investigate the potential histopathological changes induced by this new pharmaceutical combination using a newly developed refractory staining method. The findings presented herein showed no signs of treatment-related lesions or behavioral changes in Sprague Dawley rats following a three-month successive treatment with two strengths of the formula.
  • Thumbnail Image
    Publication
    Restricted
    Insulin in the saliva of pigs: Validation of an automated assay and changes at different physiological conditions
    (2021-10-20) Ortín-Bustillo, Alba; Tvarijonaviciute, Asta; Cerón, José Joaquín; Contreras-Aguilar, María Dolores; Martínez-Miró, Silvia; Martínez-Subiela, Silvia; Tecles, Fernando; Muñoz-Prieto, Alberto; Medicina y Cirugía Animal
    This study aimed to evaluate whether insulin could be measured in the saliva of pigs and if its concentration changes in some physiological conditions. For this purpose, a validation of an automated heterologous immunoassay for measuring insulin in the saliva of pigs was performed. In addition, the possible changes of salivary insulin concentration in sows after food intake and during gestation and lactation were studied. The evaluated immunoassay was able to detect insulin in the saliva of pigs in a precise and accurate way when species-specific calibrators were used. There was no correlation in insulin concentrations between serum and saliva. Insulin concentrations showed a significant increase in the saliva of sows after feeding. Sows at farrowing and lactation presented higher salivary insulin levels as compared with those in gestation. In conclusion, the results showed that insulin could be measured in the saliva of pigs, and changes in its concentration can be detected due to food intake and different physiological conditions.
  • Thumbnail Image
    Publication
    Open Access
    Metabolic profile and glycemic response in fully-grown sows born using assisted reproductive technologies
    (Elsevier, 2024-10-02) Cánovas Bernabé, Sebastián; Heras García, Sonia; Romero Aguirregomezcorta, Jon; Quintero Moreno, Armando Arturo; Gadea Mateos, Joaquín; Coy Fuster, Pilar; Romar Andrés, Raquel; Anatomía y Anatomía Patológica Comparada; Facultad de Veterinaria
    The aim of the present work was to gain insight into the metabolism of pigs derived from assisted reproductive technologies during their adulthood. Approximately 4h after feeding, a blood sample was taken from 3.5 year old sows born by artificial insemination (AI group, n = 7) and transfer of in vitro produced embryos (IVP group, n = 11) to determine the physiological concentrations of the main biomarkers of carbohydrates (glucose and lactate), proteins (albumin, creatinine and urea) and lipids (cholesterol and triglycerides). Four weeks later, an oral glucose tolerance test (OGTT; 1.75g glucose/kg body weight) was performed after an overnight fast and 1h of water withdrawal. Blood samples were obtained prior (T = 0 min; fasting conditions) and 15, 30, 45, 60, 90, 120, 150, 180, 210 and 240 min after glucose intake. At each time point, glycemia was measured immediately using glucometer test strips, and serum was collected to determine the above metabolites along with insulin and glucagon. After OGTT, the area under the curve (AUC) between sampling times and homeostasis model assessment of insulin resistance (HOMA) indices were calculated. Under physiological conditions, the concentration of metabolites studied was similar between AI and IVP sows. In both groups, fasting decreased cholesterol and increased triglycerides and urea (P < 0.001). However, creatinine and lactate were similar in both groups under physiological and fasting conditions. The expected increase in albuminemia and decrease in glycaemia after fasting was only observed in IVP sows. OGTT revealed a different glucose curve pattern (monophasic in AI and biphasic in IVP group), a lower mean concentration of cholesterol, glucose, lactate, triglycerides in IVP compared to AI pigs (P < 0.01), and a higher mean concentration of albumin, creatinine and insulin in IVP compared to AI group (P < 0.05). On the contrary, no differences were found between groups for mean serum glucagon and urea levels, nor for glucose homeostasis indices HOMA-IR and HOMA-%B. The AUC differed between groups at several time points with larger AUC for creatinine, and smaller AUC for glucose, glucagon, and triglycerides, in IVP pigs than in AI pigs at 180–210 min (P < 0.05). In conclusion, under physiological conditions the metabolic profile of fully-grown AI and IVP sows is similar and within normal ranges. Glucose challenge revealed differences in metabolic and insulin responses between groups but with normal glucose tolerance in both cases.
  • Thumbnail Image
    Publication
    Open Access
    Metabolic profile and glycemic response in fully-grown sows born using assisted reproductive technologies
    (Elsevier, 2024-10-02) Cánovas, Sebastián; Heras, S.; Quintero-Moreno, A.A.; Gadea, Joaquín; Coy, P.; Romar, Raquel; Romero Aguirregomezcorta, Jon; Fisiología
    The aim of the present work was to gain insight into the metabolism of pigs derived from assisted reproductive technologies during their adulthood. Approximately 4h after feeding, a blood sample was taken from 3.5 year old sows born by artificial insemination (AI group, n = 7) and transfer of in vitro produced embryos (IVP group, n = 11) to determine the physiological concentrations of the main biomarkers of carbohydrates (glucose and lactate), proteins (albumin, creatinine and urea) and lipids (cholesterol and triglycerides). Four weeks later, an oral glucose tolerance test (OGTT; 1.75g glucose/kg body weight) was performed after an overnight fast and 1h of water withdrawal. Blood samples were obtained prior (T = 0 min; fasting conditions) and 15, 30, 45, 60, 90, 120, 150, 180, 210 and 240 min after glucose intake. At each time point, glycemia was measured immediately using glucometer test strips, and serum was collected to determine the above metabolites along with insulin and glucagon. After OGTT, the area under the curve (AUC) between sampling times and homeostasis model assessment of insulin resistance (HOMA) indices were calculated. Under physiological conditions, the concentration of metabolites studied was similar between AI and IVP sows. In both groups, fasting decreased cholesterol and increased triglycerides and urea (P < 0.001). However, creatinine and lactate were similar in both groups under physiological and fasting conditions. The expected increase in albuminemia and decrease in glycaemia after fasting was only observed in IVP sows. OGTT revealed a different glucose curve pattern (monophasic in AI and biphasic in IVP group), a lower mean concentration of cholesterol, glucose, lactate, triglycerides in IVP compared to AI pigs (P < 0.01), and a higher mean concentration of albumin, creatinine and insulin in IVP compared to AI group (P < 0.05). On the contrary, no differences were found between groups for mean serum glucagon and urea levels, nor for glucose homeostasis indices HOMA-IR and HOMA-%B. The AUC differed between groups at several time points with larger AUC for creatinine, and smaller AUC for glucose, glucagon, and triglycerides, in IVP pigs than in AI pigs at 180–210 min (P < 0.05). In conclusion, under physiological conditions the metabolic profile of fully-grown AI and IVP sows is similar and within normal ranges. Glucose challenge revealed differences in metabolic and insulin responses between groups but with normal glucose tolerance in both cases.
  • Thumbnail Image
    Publication
    Open Access
    Metabolic profile and glycemic response in fully-grown sows born using assisted reproductive technologies
    (Elsevier, 2024-10-02) Canovas, Sebastian; Heras, Sonia; Quintero-Moreno, Armando; Gadea, Joaquin; Coy, Pilar; Romar, Raquel; Romero Aguirregomezcorta, Jon; Fisiología
    The aim of the present work was to gain insight into the metabolism of pigs derived from assisted reproductive technologies during their adulthood. Approximately 4h after feeding, a blood sample was taken from 3.5 year old sows born by artificial insemination (AI group, n = 7) and transfer of in vitro produced embryos (IVP group, n = 11) to determine the physiological concentrations of the main biomarkers of carbohydrates (glucose and lactate), proteins (albumin, creatinine and urea) and lipids (cholesterol and triglycerides). Four weeks later, an oral glucose tolerance test (OGTT; 1.75g glucose/kg body weight) was performed after an overnight fast and 1h of water withdrawal. Blood samples were obtained prior (T = 0 min; fasting conditions) and 15, 30, 45, 60, 90, 120, 150, 180, 210 and 240 min after glucose intake. At each time point, glycemia was measured immediately using glucometer test strips, and serum was collected to determine the above metabolites along with insulin and glucagon. After OGTT, the area under the curve (AUC) between sampling times and homeostasis model assessment of insulin resistance (HOMA) indices were calculated. Under physiological conditions, the concentration of metabolites studied was similar between AI and IVP sows. In both groups, fasting decreased cholesterol and increased triglycerides and urea (P < 0.001). However, creatinine and lactate were similar in both groups under physiological and fasting conditions. The expected increase in albuminemia and decrease in glycaemia after fasting was only observed in IVP sows. OGTT revealed a different glucose curve pattern (monophasic in AI and biphasic in IVP group), a lower mean concentration of cholesterol, glucose, lactate, triglycerides in IVP compared to AI pigs (P < 0.01), and a higher mean concentration of albumin, creatinine and insulin in IVP compared to AI group (P < 0.05). On the contrary, no differences were found between groups for mean serum glucagon and urea levels, nor for glucose homeostasis indices HOMA-IR and HOMA-%B. The AUC differed between groups at several time points with larger AUC for creatinine, and smaller AUC for glucose, glucagon, and triglycerides, in IVP pigs than in AI pigs at 180–210 min (P < 0.05). In conclusion, under physiological conditions the metabolic profile of fully-grown AI and IVP sows is similar and within normal ranges. Glucose challenge revealed differences in metabolic and insulin responses between groups but with normal glucose tolerance in both cases.
  • Thumbnail Image
    Publication
    Open Access
    Preliminary results on glycaemic response after oral glucose tolerance test (OGTT) in sows derived from assisted reproductive technologies
    (Association of Embryo Technology in Europe, 2023) Quintero-Moreno, Armando; Canovas, Sebastian; Heras, Sonia; Gadea, Joaquin; Romar, Raquel; Romero Aguirregomezcorta, Jon; Fisiología
    In human, murine and rabbit species, individuals derived from embryos produced in vitro (IVP) may present, among others, disorders in glucose metabolism (Chen et al. 2014, Diabetes 63:3189–3,98; García-Domínguez et al. 2020, Animals 10:1043-1059). In pigs, available information is very scarce and we have reported in 45-days-old piglets differences in the glycaemic response after an oral glucose tolerance test (OGTT) between IVP-produced animals and those conceived in vivo by artificial insemination (AI) (Paris-Oller et al. 2022, JDOHaD 13:593-605). However, it is unknown if these differences are corrected or maintained during adult life. The objective of the present study was to evaluate the glucose tolerance in the same colony of pigs during their adult life by means of an oral glucose tolerance test (OGTT). The animals were obtained from a previous study (Paris-Oller et al. 2021, J Anim Sci Biotech 12:32-44) that were born after artificial insemination (AI group) and surgical transfer of in vitro-produced embryos (IVP group). All animals were kept under same housing and feeding conditions since birth. The OGTT was performed in AI (n=8) and IVP (n=10) sows with 3.5-3.6 years age, and weighing from 227 to 249 kg. For the OGTT, animals were previously fasting for 24h and 2h without drinking water. Sows ingested 1.75 g/kg body weight of glucose solution (100% glucose carbs, Myprotein) and blood samples were collected via auricular vein before OGTT (t=0) and over 240 minutes (15, 30, 45, 60, 90, 120, 150, 180, 210 and 240 min) following glucose administration. Blood glucose concentration was immediately measured by a glucometer (Aposan) using test strips, and blood serum was obtained and freeze (-80ºC) until determination of insulin (immunoturbidimetric method) and glucagon (10-1281-01 Mercodia, Uppsala, Sweden). Data were analysed using an ANOVA test with nested design (animal within reproductive treatment group) and reproductive treatment (AI, ET) and time of sampling and interaction treatment and time as the main factors. Data are expressed as mean ± SEM. Values of p<0.05 were considered significant. Glycaemia was influenced by time of sampling (p=0.019) and was higher in AI-derived animals than in IVP group (66.95±1.29 vs. 60.57±1.31 g/dL, p<0.001), while the interaction group and time was not significant (p=0.401). On the other hand, the insulin concentration was only influenced by the origin of the animals, with higher values in IVP than AI animals (58.66±4.88 vs. 75.79±4.27 μUI/ml, p=0.013). As for the glucagon concentration, it was similar for all the times of sampling and between groups (AI: 2.84±0.39 vs. IVP: 2.75±0.24 pmol/L, p=0.664). These observations suggest that, up to some extend, the differences in the response to OGTT in IVP-produced pigs are maintained during their adult life. Moreover, IVP sows challenged with an OGTT show changes in the insulin response. Increasing the number of animals, and determination of complementary biochemical parameters are needed for a better interpretation of the results.
  • Thumbnail Image
    Publication
    Restricted
    Saliva as a non-invasive tool for assessment of metabolic andinflammatory biomarkers in children
    (Elsevier, 2020-08) Tvarijonaviciute, Asta; Martínez Lozano, Nuria; Ríos, Rafael; Marcilla de Teruel, María C.; Garaulet, Marta; Cerón, José J.; Medicina y Cirugía Animal
    Background&aims:Epidemiological studies in school-age children are challenging, particularly thosethat aim to analyse metabolic markers on blood samples obtainedviainvasive and stressful procedures.The objective of this paper is to evaluate the use of saliva, as a non-invasive tool in epidemiologicalstudies performed in school-age children, to capture metabolic changes associated with body mass index(BMI), dietary characteristics and physical activity in both boys and girls.Methods:This is an observational study in which healthy children of ages between 8 and 12 years(n¼129, 60 girls and 69 boys) from three schools in a Mediterranean area of Spain were included. Apanel of biomarkers was measured in serum and saliva and correlated with BMI, dietary characteristicsand physical activity.Results:Significant positive correlation between serum and salivary levels were detected for CRP(r¼0.770) in all included children, and boys (r¼0.805) and girls (r¼0.775) separately (P<0.001, in allcases) and for insulin in girls (r¼0.442;P<0.05). Among all studied salivary biomarkers, insulin wassignificantly correlated with the three factors studied: positively with BMI and negatively with dietarycharacteristics (intake and composition) and physical activity (P<0.05). Obesity and diet compositionwere both positively associated to pro-inflammatory biomarkers, CRP and IL1b; while diet compositionshared with physical activity levels the correlation with IL6 (positive with energy, fat, carbohydrate andsaturated fatty acid intake, and negative with cholesterol intake and average physical activity in boys),NGF and glucose (in both cases correlations were negative with diet composition and physical activityvariables) (P<0.05, in all cases). Sex differences were detected in serum glucose and TNFa.Conclusions:Biomarkers in saliva are able to capture differences in BMI, dietary characteristics andphysical activity levels in school-age children. Saliva may potentially constitute a useful non-invasive andstress-free tool to evaluate metabolic markers of inflammation and/or metabolism related to BMI andlifestyle in a sex-dependent manner.
  • Thumbnail Image
    Publication
    Open Access
    Tyrosine hydroxylase in mouse pancreatic islet cells, in situ and after syngeneic transplantation to kidney
    (Murcia : F. Hernández, 2002) Persson-Sjögren, S.; Forsgren, Sture; Täljedal, I.B.
    Tyrosine hydroxylase (TH) is co-expressed with islet hormones in the fetal mouse pancreas. In the adult animal, the enzyme has been considered as a marker of ageing ß-cells. By immunohistochemical staining, we analyzed the expression of TH-like immunoreactivity (TH-LI), insulin-LI (INS-LI) and somatostatin-LI (SOM-LI) in adult mouse islets, in situ and after isolation and transplantation to kidney. In pancreas in situ, most TH-LI cells expressed INS-LI while less than 5% expressed SOM-LI. The total number of TH-LI cells/mm2 was significantly increased directly after isolation and in 0-day, 12-week and 52-week old grafts, but not in 3-day grafts. The proportion of TH-LI cells expressing SOM-LI increased after transplantation, amounting to about one-third by 52 weeks. As expressed per unit islet area, the frequencies of both TH/INS and TH/SOM cells increased significantly in the transplants. The results demonstrate that TH occurs in both ß-cells and D-cells of adult islets. In both cell types the enzyme appears to be responsive to the microenvironmental changes inherent in transplantation. This cellular phenotype plasticity might contribute to the altered insulin secretory dynamics in islet grafts.
  • Thumbnail Image
    Publication
    Open Access
    Zinc ions in the endocrine andexocrine pancreas of zinc deficient rats
    (Murcia : F. Hernández, 2006) Søndergaard, L.G.; Stoltenberg, M.; Doering, P.; Flyvbjerg, A.; Rungby, J.
    Objective: Zinc deficiency is a problem world-wide. Zinc and insulin are intimately related, and a reduced zinc intake may affect glucose metabolism. The present study investigates how subclinical zinc deficiency in rats affects glucose metabolism and zinc distribution in the pancreas. Methods: Glucose metabolism was evaluated by blood-glucose, serum insulin, homeostasis model assessment (HOMA), and intraperitoneal glucose tolerance tests. Immersion zincsulphide autometallography (iZnSAMG) was used to describe zinc ion distribution. Results: After 4 weeks on a zinc deficient diet (<10 ppm), the zinc deficient rats had a slightly impaired glucose metabolism characterized by significantly increased blood-glucose levels. No differences in serum insulin, insulin resistance, beta-cell function were observed. The zinc deficient rats had significantly decreased serum zinc without any clinical signs of zinc deficiency. Zinc ion staining intensity of the islets of Langerhans was unaffected by the zinc deficiency. In contrast, the acinar cells in the exocrine pancreas appeared depleted of iZnSAMG grains in the zinc deficient rats when compared with their controls. Though statistically non-significant, a reduction in total zinc of the pancreas was found. Conclusions: The present findings suggest that the endocrine pancreas is able to compensate for the subclinical zinc deficiency as it maintains an adequate zinc ion level in the secretory vesicles for insulin storage. The exocrine pancreas lacks this ability; it exhibits decreased levels of zinc ion staining as a consequence of 4 weeks of reduced zinc intake.