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ARS Home » Southeast Area » Stoneville, Mississippi » Warmwater Aquaculture Research Unit » Research » Publications at this Location » Publication #375779
Research Project: Biophotonics - The Application of Novel Imaging Methodologies to Livestock Production Research

Location: Warmwater Aquaculture Research Unit

Title: Deficiency in proliferative, angiogenic, and LH receptors in the follicle wall: implications of season toward the anovulatory condition

Author
item ISHACK, GHASSAN - Southern Illinois University
item DUTRA, GABRIEL - Southern Illinois University
item GASTAL, GUSTAVO - Southern Illinois University
item ELCOMBE, M - Southern Illinois University
item GASTAL, MELBA - Southern Illinois University
item PARK, SEONG - Mississippi State University
item FEUGANG, JEAN - Mississippi State University
item GASTAL, EDUARDO - Southern Illinois University

Submitted to: Domestic Animal Endocrinology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/24/2019
Publication Date: 7/31/2019
Citation: Ishack, G., Dutra, G., Gastal, G., Elcombe, M., Gastal, M., Park, S., Feugang, J., Gastal, E. 2019. Deficiency in proliferative, angiogenic, and LH receptors in the follicle wall: implications of season toward the anovulatory condition. Domestic Animal Endocrinology. 70:106382.

Interpretive Summary: Ovarian folliculogenesis in mammals is a complex process regulated by autocrine, paracrine, and endocrine factors [1], with thyroid hormones (TH), triiodothyronine (T3) and thyroxine (T4), influencing follicular development. The influence of the insulin-to-thyroxine balance on the development of cultured early preantral follicles is still unclear. In the present study, the combination of low concentrations of insulin and thyroxine better maintained follicle survival, while high levels ensured better follicular development.

Technical Abstract: Here we investigated the in vitro effects of thyroxine combined with insulin on caprine preantral follicle survival and development. Sliced ovarian tissues were cultured for 1 or 7 days using 10 ng/mL (low) or 10 µg/mL (high) insulin in the presence of thyroxine at 0, 0.5, 1 or 2 µg/mL. Post-culture, we evaluated the follicular survival and development, assessed the expression of apoptotic-related genes (Bcl2/Bax) and receptors of insulin and thyroid hormones, and quantified the estradiol and reactive oxygen species (ROS) production levels. Follicular survival in low-insulin culture conditions was enhanced by the presence of 0.5 µg/mL thyroxine (P < 0.05) as compared to the thyroxine-free medium but remained similar to non-cultured control in the presence of 2 µg/mL (P > 0.05). Significantly higher ROS production was measured from Day 1 to Day 7 in low-insulin culture media containing 0.5 or 2 µg/mL thyroxine (P < 0.05). When compared to high insulin level, the presence of thyroxine in low insulin culture conditions yielded higher stromal cell density (P < 0.05), increased estradiol production on Day 1, and higher Bcl2/Bax ratio on Day 7. Cultures with high levels of both insulin and thyroxine led to follicles and oocytes with larger diameters (P < 0.05). The RNA transcript levels of insulin and thyroid receptors were reduced in the presence of high insulin cultures when compared to controls (non-cultured).