Effect of neonatal hypothyroidism on carbohydrate metabolism, insulin secretion, and pancreatic islets morphology of adult male offspring in rats.
BACKGROUND
Neonatal hypothyroidism has serious effects on growth, development, and metabolism.


OBJECTIVE
This study aims to investigate the effects of the neonatal hypothyroidism on carbohydrate metabolism, islet insulin secretion and morphology of the pancreatic islets in adult male offspring.


METHODS
Lactating mothers of Wistar rats consumed 0.02% solution of 6-propyl-2-thiouracil during the weaning period (neonatal hypothyroid group), while mothers of the control group drank merely tap water. Body weight and survival of pups were followed up. Intravenous glucose tolerance test was performed in adult male offspring and 5-6 weeks later, glucose-stimulated insulin secretion (GSIS) was evaluated.


RESULTS
During the glucose tolerance test, plasma glucose level of the neonatal hypothyroid group (13.18 ± 0.59 mmol/l) was significantly higher at 5 min compared to the control group (11.54 ± 0.47 mmol/l), whereas plasma insulin concentrations and GSIS of the groups was not significantly different. Homeostasis model assessment of insulin resistance of adult male offspring of the hypothyroid group (9.1 ± 1.0) was significantly higher as compared to the control group (4.5 ± 0.6). Area (14,613.0 ± 2646.3 μm2) and the diameter of the islets (147 ± 3.0 μm) of the neonatal hypothyroid group were significantly lower, as compared to the control group (32,886.3 ± 4690.3 and 206.6 ± 5.9 μm2 and μm, respectively).


CONCLUSIONS
Neonatal hypothyroidism can alter carbohydrate metabolism in euthyroid adult offspring, which may increase susceptibility to the development of glucose intolerance and occurrence of Type 2 diabetes later in life.
Department of Physiology, the Medical School, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
H
H
Farahani
A
A
Ghasemi
M
M
Roghani
S
S
Zahediasl
D000818:Animals; D000831:Animals, Newborn; D001786:Blood Glucose / Q000378:metabolism; D050260:Carbohydrate Metabolism; D003924:Diabetes Mellitus, Type 2 / Q000175:diagnosis / Q000209:etiology*; D005260:Female; D005951:Glucose Tolerance Test; D007037:Hypothyroidism / Q000150:complications* / Q000503:physiopathology; D007328:Insulin / Q000378:metabolism*; D007333:Insulin Resistance; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000473:pathology*; D007774:Lactation; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D013974:Thyroxine / Q000378:metabolism
D001786:Blood Glucose; D007328:Insulin; D013974:Thyroxine