The Effect of Maternal Hypothyroidism on the Carbohydrate Metabolism and Insulin Secretion of Isolated Islets in Adult Male Offspring of Rats

Abstract

Thyroid hormones have crucial developmental effect during fetal life. This study investigates the effects of maternal hypothyroidism on the carbohydrate metabolism and insulin secretion capacity of islets of the adult male offspring of rats. One group of pregnant mothers (fetal hypothyroid) of Wistar rats drank water containing 0.02% of 6-propyl-2-thiouracil during pregnancy, while the control group consumed only tap water. After delivery, survival and weight of the neonates from both groups were followed. In adult male offspring, the intravenous glucose tolerance test was performed and 5-6 weeks later, glucose-stimulated insulin secretion of isolated islets was assessed. Plasma glucose concentration of the fetal hypothyroid group during intravenous glucose tolerance test was significantly higher (p=0.003) at 5-20 min as compared to the control group, whereas plasma insulin concentration was significantly lower (p=0.012) at 5-20 min. Insulin secretion of the isolated islets stimulated with 16 mM glucose of the offspring in the fetal hypothyroid group (376.2 ± 57.1 pmol/islet/60 min) was significantly lower (p=0.02) as compared to the control group (618.1 ± 85.2). Although adult offspring born from hypothyroid mothers were euthyroid, their glucose tolerance and glucose stimulated insulin secretion of islets were altered, which may eventually contribute to the development of diabetes.

Transient Congenital Hypothyroidism Alters Gene Expression of Glucose Transporters and Impairs Glucose Sensing Apparatus in Young and Aged Offspring Rats

“…In our study, TCH rats had lower weight both at birth and until month 3, similar to previous reports [10, 11]. Weight gain was, however, similar between groups during months 3 to 19; a finding in keeping with our previous reports on TCH rats followed until month 12 [10, 44].…”

“…The incidence of TCH is very low in iodine-sufficient areas such as the United States (1 in 50000) or very high in the iodine-deficient areas such as Europe (1 in 100) [6] and Africa (1 in 10) [9]. Hypothyroidism during pregnancy can cause glucose intolerance during adulthood [10, 11] that is a result of disturbed intrauterine conditions [12, 13]. …”

Comparison of the effects of acute and chronic psychological stress on metabolic features in rats

“…Fasting plasma glucose and insulin were measured to determine HOMA-IR index, the formula is: HOMA-IR=(c i ×c g )/22.5, where c i is fasting insulin level (µU/ml) and c g is fasting glucose level (mmol/L) (Farahani et al, 2010).…”

Aortic Intima-Media Thickness in Newborns with Congenital Hypothyroidism

“…However, the important point is that the detrimental effect of TH deficiency begins in the early fetal life roughly after 12 weeks, which is the initiation of TH synthesis. Earlier studies revealed that fetal hypothyroidism has a worsening effect on brain development [22], cardiovascular development and functions [23,24], the reproductive system [25], skeletal muscle development [26] and glucose-insulin metabolism [27]. Additionally, optimizing the lipoprotein/lipid profile may take longer time.…”