67 The Role of Thyrotropin-releasing Hormone(TRH) and Histidyl-proline Diketopiperazine(HPD) in the Maturation of Thermogenesis in Growing Rats

Abstract

The echo patterns of diffuse thyroid lesions in children are not yet well known. We present here the ultrasound findings of 32 children aged 5 to 15 years with a newly diagnosed diffuse thyroid disease. 23 patients had thyromegaly by palpation, 9 had hypothyroidism but no goiter. Of the 23 goitrous patients 9 were hypo-, 3 hyper-and 11 euthyroid. The 9 with hypothyroidism had all autoimmune thyroiditis as judged by antithyroid antibodies, and confirmed cytologically in 5. They had all 9 a hypoechogenic patchy, partly nodular thyroid by ultrasound.2 of the 3 with Graves disease had initially a similar pattern than in thyroiditis, the 3rd showed hypoechogenity later. Of the 11 euthyroid patients 8 had antithyroid antibodies and the ultrasound suggested thyroiditis in 5 of them, 3 were judged normal (2 and 1 became later hypothyroid). Of the 3 patients with euthyroid goiter but without antithyroid antibodies the ultrasound finding was normal in 1, showed multicystic thyroid in 1 and suggested thyroiditis in 1 who later had antithyroid antibodies. Of the 9 hypothyroid patients without thyromegaly one had an unusually small hit otherwise normal thyroid by ultrasound. The others had an echopoor thyroid, but the patchy and nodular pattern was often less marked than in goitrous hypothyroidism. We conclude that autoimmune thyroiditis gives a typical ultrasound pattern, and ultrasonography gives useful information especially of euthyroid goiter and nongoitrous hypothyroidism. PERICARDIAL EFFUSION IN CONGENITAL HYPOTHYROID/ ; A 1NFANTS:AN AETIOLOGICAL CORRELATION. Gianfili~po -" ...~e h children positive at the newborn screen'ing program for congenital hypothyroidism were studied. Confirmlng diagnosis was made in 8/10 infants,while 2/10 were false positive. Moreover we have considered in the study a patient clinically diagnosed at 19 months (he did not undergo the screening prograrn),in which was demonstrated an ectopic g1and.A complete thyroid function evaluation (FT3,FT4,T3,T4,TBG,TRH test),scintlgraphy (TC99),echocardiography (B-mode)were carried out in all the babies (scintigraphy was not performed in the 2 false positive children). Pericardial effusion was demonstrated in 4/9 patients (44%); complete resolution occurred after a variable period of L-T4 therapy (15 days to 5 months).None of the patients showed clinical symptoms nor electrocardiographrc signs of cardiac failure. Data collected in Zaire suggested that severe iodine deficiency resulted in neonatal hypothyroidism and its longterm consequence, endemic cretinism. In order to further evaluate this possibility, we initiated neonatal thyroid screening in an endemic goiter area in Algeria (area A) with a high prevalence of goiter (51.3 %) and cretinism (1.1 %) and a low dietary supply of iodine (I)(Mean urinary I : 16.2 uglg creatinine) and in a non goitrous area (B) with no cretinism and a normal iodine supply (urinary 1:73.9 ug/g creat.). Serum TSH levels in 3135 newborn infants of area A were shifted towards high values as compared to the results obtained in a...

Thyroid hormone-catecholamine interrelationship during cold acclimation in rats Compensatory role of catecholamine for altered thyroid states

“…In addition to the stimulation of TSH release, thyrotropin-releasing hormone (TRH) accelerates CA turnover (Keller et al 1974) and produces a rise in plasma NE and E in rats (Brown 1981). Furthermore, we have observed that intrathecally administered TRH produced hyperthermia in young rats (Sato et al 1985). These findings led to the concept that TRH may play a regulatory role in thermogenesis.…”

“Ferrocrinology”—Iron Is an Important Factor Involved in Gluco- and Lipocrinology

“…The adrenergic response is integrated in the preoptic/anterior hypothalamic (POAH) area, which contains thermosensitive neurons [ 14 ]. Thyrotropin-releasing hormone (TRH) administration was shown to increase norepinephrine levels and stimulate catecholamine metabolism [ 15 ]. The sympathetic stimulation can alter blood flow, resulting in a decrease in heat loss and an increase in heat production via its effects on the brown adipose tissue.…”

“…As already mentioned, the endocrine system stimulation in response to low temperatures is mediated by POAH neurons. In a study by Sato et al from 1985, TRH administration resulted in hyperthermia in rats [ 15 ]. Beard, Green, Miller, and Finch observed no increase in TSH levels after 6 and 24 h of cold exposure in iron deficient rats [ 30 ].…”