Simultaneous Melatonin Administration Effectively Deprograms the Negative Influence of Neonatal Hypothyroidism on Immature Follicles but not on Mature Follicles and Body and Ovarian Weights

Abstract

Background: The impact of simultaneous melatonin administration on neonatal progmming by hypothyroidism (HPOT + MT) on adult ovarian functions and serum hormone profiles has been evaluated in the Charles foster strain of rats. Methods:The female neonates were rendered hypothyroid (HPOT) by feeding lactating mothers with 6-propyl 2-thiouracil (PTU) through drinking water and were simultaneously administered with melatonin (MT) (40 µg/animal/day) from day 0 to day 21 in the evening at 16:30 hours just prior to lights off. Results:The experimental animals (HPOT + MT) consistently showed decreased body and ovary weights compared to controls. The total number of follicles was significantly lower in treated animals (HPOT + MT) but was greater than the HPOT group of animals, and both showed significantly decreased number of follicles compared to control rats. There was a significant reduction in the number of antral follicles and corpora lutea and decreased atretic follicles in experimental rats. Conclusions:It can be concluded from the above results that melatonin is able to nullify the negative influence of hypothyroidism on adult ovarian functions and steroidogenesis to a greater extent.

Morphological and functional changes in pituitary‐thyroid axis following prolonged exposure of female rats to constant light

“…Thyroid hormones (TH) play essential roles in regulation of energy expenditure, as well as in regulation of growth and maturation of many organs and systems, including brain, skeleton, and reproductive organs (Mann et al, 2006;Thakkar et al, 2011). Secretions of TSH and thyroid hormones are of circadian nature (Weeke and Gundersen, 1978;Jordan et al, 1980).…”

Effects of Simultaneous Melatonin Administration on the Testis of the Experimentally Induced Hyper- and Hypothyroidism in the Adult Male Albino Rat

“…On the other hand, Thakkara et al [9] observed that, simultaneous melatonin administration effectively deprogramed the negative influence of neonatal hypothyroidism on immature follicles but not on mature follicles and body and ovarian weights. This different finding may be attributed to the different organ (ovary) they worked on.…”

“…The most common disorders of the thyroid gland are hyperthyroidism and hypothyroidism [1] . Hyperthyroidism is a condition in which the thyroid gland secretes too much thyroid hormone and hypothyroidism results in insufficient amounts of thyroid hormone [9] . Both hyperthyroidism and hypothyroidism have been linked to cell damage [10][11][12] .…”

“…Hyperthyroidism, or overactive thyroid, is most commonly a result of an autoimmune disease. Occasionally, it can result from a non-cancerous tumor in the thyroid gland or an infection of the thyroid gland [9] .…”

Can constant light exposure affect the thyroid gland in prepubertal male albino rats? Histological and ultrastructural study

“…T4 is the dominant hormone released from the thyroid gland, while T3 is biologically more active and originates mainly from peripheral deiodination of T4 [5]. Thyroid hormones play essential role in regulation of metabolic rate, regulation of growth, maturation of many organs and systems, including brain, skeleton, reproductive organs and energy expenditure [24,37].…”