Hormones and Reproductive Cycles in Rodents

Thyroid and reproduction in amphibians and reptiles

“…Limited studies of both amphibians and reptiles indicate that the thyroid condition affects gonadal development and reproduction. The negative effects reported for thyroid hormones on the reproductive organs of larval amphibians and adult reptiles are in marked contrast to the many positive correlations reported for fishes (Deal & Volkoff, 2020; Raine, 2011; Tovo‐Neto et al, 2018), birds (Ubuka & Bentley, 2011), and mammals (Bales & Holsetler, 2011). Although the evidence is clear that thyroid hormones are important in some way for normal reproduction in both amphibians and reptiles, most of the data relating positive or negative actions of thyroid hormone on reproduction in amphibians and reptiles are correlative and do not support a cause–effect relationship.…”

“…Limited studies of both amphibians and reptiles indicate that the thyroid condition affects gonadal development and reproduction. The negative effects reported for thyroid hormones on the reproductive organs of larval amphibians and adult reptiles are in marked contrast to the many positive correlations reported for fishes (Deal & Volkoff, 2020;Raine, 2011;Tovo-Neto et al, 2018), birds (Ubuka & Bentley, 2011), and mammals (Bales & Holsetler, 2011). Although Finally, it is important to consider that the reproductive systems of both amphibians (Carr, 2011) and reptiles (Tokarz & Summers, 2011) can be strongly affected by the HPA axis via stress-induced secretion of corticosteroids, especially in captive animals.…”