6-Hydroxydopamine (6-OHDA) (two doses of 200 micrograms each, administered intraventricularly at a 48 h interval) caused a marked decrease of hypothalamic noradrenaline content and blocked the TSH rise elicited by cold exposure. Clonidine (0.4 mg/kg i.p.), a noradrenaline receptor agonist, was able to reverse the 6-OHDA of cold-induced TSH surge. The plasma TSH levels after cold stress in rats treated with 6-OHDA + clonidine were significantly higher than in vehicle + clonidine-injected animals, thus suggesting the presence of noradrenaline receptor supersensitivity in 6-OHDA-pretreated rats. 6-OHDA did not modify the basal concentrations of TSH but the administration of clonidine to 6-OHDA-injected animals caused a significant increase in thyrotropin secretion when compared with the vehicle + clonidine group.
Effect of 6-hydroxydopamine treatment on TSH secretion in basal and cold-stimulated conditions in the rat / Schettini, G.; Quattrone, A.; DI RENZO, GIANFRANCO MARIA LUIGI; Lombardi, Gaetano; Preziosi, P.. - In: EUROPEAN JOURNAL OF PHARMACOLOGY. - ISSN 0014-2999. - ELETTRONICO. - 56:(1979), pp. 153-157.
Effect of 6-hydroxydopamine treatment on TSH secretion in basal and cold-stimulated conditions in the rat
DI RENZO, GIANFRANCO MARIA LUIGI;LOMBARDI, GAETANO;
1979
Abstract
6-Hydroxydopamine (6-OHDA) (two doses of 200 micrograms each, administered intraventricularly at a 48 h interval) caused a marked decrease of hypothalamic noradrenaline content and blocked the TSH rise elicited by cold exposure. Clonidine (0.4 mg/kg i.p.), a noradrenaline receptor agonist, was able to reverse the 6-OHDA of cold-induced TSH surge. The plasma TSH levels after cold stress in rats treated with 6-OHDA + clonidine were significantly higher than in vehicle + clonidine-injected animals, thus suggesting the presence of noradrenaline receptor supersensitivity in 6-OHDA-pretreated rats. 6-OHDA did not modify the basal concentrations of TSH but the administration of clonidine to 6-OHDA-injected animals caused a significant increase in thyrotropin secretion when compared with the vehicle + clonidine group.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
