The Immunohistochemical Effect of Maternal Hypothyroidism and Hyperthyroidism during Pregnancy and Lactation on Skin Development in Wistar Rat Newborns

Previous studies have shown that thyroid hormones are necessary for normal development of many tissues in the human body. So In this investigation, the effect of maternal hypothyroidism on neonatal skin development was studied using immunohistochemistry technique. Rats were divided in 4 groups hypothyroid, hyperthyroid, hypothyroid treated with thyroxin and control, each group containing 10 rats. 14 days before mating, hypothyroid, hyperthyroid and hypothyroid treated with thyroxin groups, were respectively exposed to Propylthiouracil (PTU) (50 mg/lit), levothyroxin 1 mg/lit and both PTU (50 mg/lit) and levothyroxin (1 mg/lit) simultaneously. After 14 days, blood test was taken from mothers and in the case of desired changes in hormone levels, rats were allowed to mate. After pregnancy and delivery, the dorsal skins of the 10 days old newborns were used for immunohistochemical studies. in this study, in most area of skin, significant increase of laminin expression in hypothyroid groups (p=0.002) and significant decrease of laminin expression in hyperthyroid groups (p=0.007) were observed. Also in treated hypothyroid with thyroxin rather than control group no significant difference was observed. Maternal hypothyroidism causes considerable changes in the expression of laminin in different areas of skin. While maternal hyperthyroidism causes opposite results in laminin expression. In fact, thyroid hormone causes negative regulation of laminin expression. There fore, rising of thyroid hormone levels leads to a decrease in laminin expression and overhand. So,changes in thyroid hormones level can cause various changes in different areas of newborns skin.