Effect of cold exposure on the hypothalamic release of thyrotropin-releasing hormone and catecholamines.

摘要: The effects of cold exposure on the release thyrotropin-releasing hormone (TRH) and catecholamines as estimated by push-pull perfusion mediobasal hypothalamus were studied. Before exposure, male rats had been kept at room temperature or 30 degrees C for 3 weeks. Transfer to 4 increased plasma levels thyroid-stimulating (TSH), but this cold-induced TSH response was more pronounced in animals which acclimatized C. Exposure also thyroid levels, no effect prolactin. hypothalamic content TRH dopamine remained similar after transfer C, 6 h cold, noradrenaline adrenaline 1.6-fold 3-fold, respectively. In vivo TRH, during a 2-hour period control did not change transferred from amount perfusate low temperatures. However, these weeks, first 15 min (2-fold increase). Thus, stimulates hypothalamo-pituitary-thyroid axis increases