Thyrotropin-releasing hormone and somatostatin inhibit each others release in vitro in the rat retina

Abstract

The effect of thyrotropin-releasing hormone (TRH), somatostatin (SS) or octreotide, an analogue of SS, on release of TRH or SS from the rat retina was studied in vitro. The retina was incubated in medium 199 (pH 7.4) with 1.0 mg/ml of bacitracin (medium) for 20 min. The amount of TRH or SS release into the medium was measured by individual radioimmunoassays. The TRH release from the rat retina was inhibited significantly in a dose-related manner by the addition of SS or octreotide. The SS release from the retina was inhibited by TRH, and the inhibitory effect of TRH on SS release from the rat retina was blocked by the addition of anti-TRH receptor antiserum immunoglobulin fraction. The findings suggest an interaction between TRH and SS in the rat retina by which the addition of one inhibits the release of the other.

Expression of hypothalamic neurohormones and their receptors in the human eye

“…The expression of hypothalamic hormones and their receptors in the mammalian eye has been previously reported, mainly using rat models and mostly limited to retinal tissue [ 34 – 39 ]. Somatostatin receptors have been previously described in the human retina and other ocular structures [ 40 – 43 ] as has TRH, which has also been identified in human retina [ 44 ].…”