Prostate-thyroid axis: Prostatic TRH is one of the stimulators of thyroid hormone

Ventral prostatectomy decreased serum thyroid hormones and histology of the thyroid gland indicate that hypothyroid condition. Go-culture of thyroid g land and ventral prostate stimulates thyroid hormone secretion. In the pres ent study we report prostatic thyrotropin releasing hormone (TRH) is the st imulating factor of thyroid hormone secretion. Mature rat (90 days old) ven tral prostate, anterior pituitary and thyroid glands were co-cultured in vi tro with or without TRH antibody to assess the direct influence of prostati c TRH on thyroid hormone secretion. Total thyroxine (T4) and triiodothyroni ne (T3) were increased significantly in the culture media of ventral prosta te, anterior pituitary and thyroid gland when compared with thyroid gland p lus anterior pituitary culture media. However, media T4 and T3 concentratio n decreased significantly in thyroid gland alone; also in thyroid gland plu s ventral prostate, thyroid gland plus anterior pituitary and thyroid gland plus anterior pituitary plus ventral prostate were co-cultured with TRH an tibody (Ab) in a dose dependent manner. The results suggest that ventral pr ostatic TRH is one of the stimulating factors of thyroid hormone secretion under these in vitro conditions.