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COMPARISON OF THE EFFECT OF MATERNAL HYPOTHYROIDISM ON CARBOHYDRATE METABOLISM IN YOUNG AND AGED MALE OFFSPRING IN RATS. Narges Karbalaee *, Saleh Zahediasl , Asghar Ghasemi , Farzaneh Faraji Shahrivar
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COMPARISON OF THE EFFECT OF MATERNAL HYPOTHYROIDISM ON CARBOHYDRATE METABOLISM IN YOUNG AND AGED MALE OFFSPRING IN RATS. NargesKarbalaee*,SalehZahediasl, AsgharGhasemi, FarzanehFarajiShahrivar Endocrine Research Center, Research Institute for Endocrine Sciences, ShaheedBeheshti University of Medical Sciences, Tehran, Iran Karbalaee
IntroductionCritical periods of development (Composite data are from rodents and humans)
Introduction (cont.)Causes and consequences of intrauterine programming
Introduction (cont.) adulthood Hypertension Hyperlipidemia Intrauterine growth retardation Reproductivedisorders Renal failure Ischaemic heart disease Obstructive pulmonary disease Insulin resistance Glucose intolerance Type 2 diabetes
Introduction (cont.) There are evidences that maternal hormonal status markedly influence intra-uterine growth and developmen Cardiovascular Hemodynamic CNS Reproductive system Metabolic Activities in Most Tissue Liver function Growth and Development Immune System
Introduction (cont.) Thyroid hormones act as metabolic and maturational signals, any changes in the levels of these hormones in uterus alters fetal development and has long term consequences for cardiovascular, reproductive,andmetabolic function. There is a relationship between serum thyroid hormone levels and diabetes riskand also various abnormalities in carbohydrate metabolism occur in patients with thyroid disease. Soabnormalities in carbohydrate metabolism may take place in fetal hypothyroidism. Karbalaee
Aim This study aims to assess the glucose tolerance and insulin secretion capacity of islets in young and aged male offspring of mothers who were hypothyroid during pregnancy. Karbalaee
Materials & Methods Male and female Wistar rats were crossed for 24 h Pregnant femaleWistar rats Animals and study design Control Pregnant rats consumed tap water during gestation Fetal Hypothyroid Pregnant rats received water containing 0.02 % of PTU during gestation Delivery Male offspring (3 and 12 month) Mother and Offspring (Blood) Thyroid hormones (T3, T4) Assessed for
Material and Methods Intravenous Glucose Tolerance Test (IVGTT) • In young and old male offsprings,after over night fasting (12 h), IVGTT was carried out by intravenous infusion of 50% glucose (0.5 g/kg body weight) • The plasma glucose and insulin levels of rats were assayed at 0, 5,10,15, 20, 30, and 60 minutes after an intravenous glucose load.
Material and Methods Glucose-stimulated insulin secretion (GSIS) ASSAY • Islet isolation • Incubation with different glucose concentrations (5.6, 8.3, 16.7 mM) ( 60 min, 37°C ,95 % O 2 / 5 % CO 2 ) • Collection of supernatant for insulin determination Karbalaee
Materials & Methods (cont.) Measurements • Weight • Plasma T3 & T4(ELISA kits ) • Plasma Glucose concentration(glucose oxidase method ) • Plasma Insulin concentration(ELISA method ) Karbalaee
Results Karbalaee
Table I. Plasma T3 and T4 concentration in the fetal hypothyroid of control groups at birth and adulthood (3 and 12 months ), and their mothers at the time of delivery. Values are means ± SEM. * p< 0.05, *** p<0.0001 and *** p<0.0001 Significant difference compared to controls Karbalaee
Table II. Effect of hypothyroid during pregnancy on reproductive performance. a Percent weight gain relative to the weight on day 1 of pregnancy. Day 1 weight in all groups ranged from 180-220 g. bAll pups in a litter were weighed and the average pup weight of a litter computed and reported as a single point. This was done for all litters in a group and the mean of these points is reported as the group mean in the table. Values are means ± SEM. * p< 0.05 and *** p<0.001 Significantly from control Karbalaee
Body weight in control and Fetal hypothyroid (FH) male offspring rats. Values are mean ± SE ; n=14. Karbalaee
Plasma glucose and insulincocentrations and their AUC during intravenous glucose tolerance test in the young ( a , c n = 11) and old ( b , d n = 12) rats of fetal hypothyroid and control groups. Values are mean ± SE.
Comparison of the islets insulin secretion in the fetal hypothyroid and control groups in old ( a) and young (b) rats. Values are means ± SE Karbalaee
Conclusions The results of this study have shown that maternal hypothyroid during pregnancy leads to: • Intrauterine growth restriction in rat fetuses • Glucose intolerance and lower insulin secretion capacity in their adult off spring particularly in aged animals. From the results of this study we can conclude that carbohydrate metabolism in the offspring of fetal hypothyroid subjects is a matter of concern particularly in the old ages. Karbalaee
Thanks for your attention Karbalaee
Definition of term `programming‘ A stimulus or insult during a critical or sensitive period of development can have long-term or lifetime effects on an organism’, as well as with the ‘predictive adaptive response’ . (Holness ,2000; Hales and Barker (2001 Lucas A, 2000; Gluckman PD,,2006) • Disturbance in the metabolic intrauterine environment alters the development of the endocrine pancreas and the insulin sensitive tissues. • lPerturbed nutritional and hormona environment are responsible for the altered β-cell mass. Ghasemi
Diagram illustrating the relationships between nutritional state, hormone concentrations, metabolism and tissue accretion and differentiation in the fetus.(A L Fowden and A J Forhead(2004)