Effect of Thyrotropin-Releasing Factor in Man

Abstract

This study reports the changes of plasma TSH levels which occurred when a highly purified preparation of porcine TRF was given to 3 cretins. These results in man indicate a certain lack of species specificity since TRF prepared from the hypothalami of pigs was active in the mouse and rat as well as man. The levels of TSH were measured by both bioassay and radioimmunoassay and were found to rise within 3 min in 2 of the patients and by 6 min in all 3 patients. The greatest rise was from 6 to 30 min and was followed by a gradual decline of the TSH level over the next 45 min. When the plasma level of TSH was measured in one of the patients 120 min after injecting TRF, it had returned to the base line level. Some conditions considered important for testing the activity of TRF in man are given. Because of the limited supply of TRF available, it was not possible to determine if the above were the optimal conditions for detecting the TRF response in man. (J Clin Endocr 28: 978,1968) A SERIES of beautiful and specific studies was performed within the last 20 years which indicated that thyrotropin (TSH) released from the anterior pituitary gland (APG) was dependent on the hypothalamus (1, 2). To increase the release of TSH with electrodes placed into the hypothalamus, it was necessary to stimulate the preoptic area. To decrease the release of TSH it was found that either the removal of the pituitary gland and its transplantation away from its normal anatomical site, the severing of the anatomical connection between the hypothalamus and pituitary gland, or the localized destruction of specific areas in the hypothalamus was effective in each instance. It was concluded from these studies that the hypothalamus and anterior pituitary gland functioned as a unit to regulate TSH release. Since it had been established that a vascular link in which blood flowed from the hypothalamus to the APG was the only connection between these two organs, it was also concluded that a humoral substance had been formed in the hypothalamus and secreted

The effect of glucocorticoids on thyrotropin secretion

“…Subsequently, this accumulated TRF might be rapidly released and therefore briefly stimulate TSH secretion through its known pituitary action. Whatever the mechanism of the TSH rebound, it represents the first demonstration of increased TSH secretion in the adult not resulting from either reduced circulating thyroid hormone concentrations or TRF administration (16). It also suggests that alterations in TSH secretion are not determined entirely by changing plasma thyroid hormone levels interacting with unvarying TRF concentrations at the level of the pituitary thyrotroph, but that alterations in TRF secretion can also participate in regulating TSH secretion.…”

Endocrine approaches to treatment of Alzheimer's disease and other neurological conditions

“…It may be important to mention that our collaborative clinical publications on hypothalamic hormones involved TRH [2,13,14,30] collaborator at Tulane University in New Orleans, Dr. Cy Bowers, as the leading author, and myself. Dr. Carlos Gual and Abba Kastin were co-authors [2,13,14,30].…”

“…Dr. Carlos Gual and Abba Kastin were co-authors [2,13,14,30]. These studies on TRH have been cited in our various book chapters [30].…”

“…This favorable situation and so many publications on hypothalamic hormones were of course due to our fruitful work on TRH [2,13,14,30]. There was also the issue of our clear leadership in the chemical, physiological and clinical advances on LH-RH [26,43,[47][48][49][50][51]72,90,93].…”

“…Part III: Experimental studies on antagonists of LH-RH and GH-RH in animal models of Alzheimer's disease: Projections for treatment of other neurological conditions. Peptides (2015), http://dx.doi.org/10.1016/j.peptides.2015.03.009 this analog [D-Tpi 6 ,Leu 13 (CH 2 NH)-Leu 14 ]BN (6)(7)(8)(9)(10)(11)(12)(13)(14) is completely different from that of GHRH analogs indicating that multiple classes of peptides can affect behavior and induce extinction of memory. These findings support the merit of further studies aimed at neuro-psychiatric applications of such analogs for the treatment of patients with fear-related disorders.…”