A novel thyrotropin-releasing hormone-leptin interaction.

SILVIA INES, GARCIA; PORTO PATRICIA,; ALVAREZ AZUCENA,; MARIANO LUIS, SCHUMAN; FINKIELMAN SAMUEL,; CARLOS JOSE, PIROLA

Chicago, USA

Congreso; Council for High Blood Pressure Research,; 2001

American Heart Association.

Leptin,an adipocyte-released hormone, modifies food intake and energy expenditure regulating hypothalamus-pituitary-thyroid axys function. Here we studied plasma leptin levels (EIA) in male Wistar rats made hypertensives by periventricular tliyrotropin-releasing hormone (TRH) overproduction induced by icv injection of the eucariotic expression plasmid containing the preTRH cDNA (pCMV-TRH). After 24-48 hours, 100 ug of pCMV-TRH decreased leptin plasma levels and a preTRH antisense. reverted this effect (table) Male and female SHR having increased central TRH system activity showed lower levels of circulating leptin than their sex-matched WKY controls (table).This difference was abated by a preTRH antisense. These dala suggest in TRH-induced hypertension leptin is decreased inducing compensatory adiposity. We, propose that as leptin produces central TRH synthesis and release, obesity mayinduce hypertension  through the TRH system activation, then the TRH-leptin interaction may contribute to the strong association  hypertension and obesity.plasma leptin concentrations in pCMV-TRH-treated rats and female and male SHR and WKY controls effect of prel TRH artisense (AS) Vehicle  preTRH AS - pre TRH inverted ASWístar Control 9 4±1 5 9.1±2 0 7,9±2,1Wistar pCMV-TRH 53-13 9,0±1.2 t 4 8±1 4Female WKY 7.2±1 2 8.2±1.3 7 5±2 2Male WKY 12 O±1 4 # lo ,,~ U 11.6-2.0Female SHR 4.8±09 T 8 9+-l.5 1 5.1±1 8Male SHR 8.7+-0,9n# 3.7±,64 9.4±1.4Results are expressed as mean±SD, n=6, ANOVA.  p<0.05 vs Wistar control 0: p<0.05 Vs females.  p<0.05 vs sexmatched WKY, t p<0 05 vs vehicle