Mechanisms involved in the long-term modulation of tyrosine hydroxylase by endothelins in the olfactory bulb of normotensive rats

Chronic Blockade of Brain Endothelin Receptor Type-A (ETA) Reduces Blood Pressure and Prevents Catecholaminergic Overactivity in the Right Olfactory Bulb of DOCA-Salt Hypertensive Rats

“…Moreover, the increase in norepinephrine release stimulated by ETs in the OB suggests that it contributes to enhance TH activity by reducing the feedback inhibition evoked by the amine. In a later study, we reported that long-term exposure to ETs enhances TH mRNA and the expression of total TH and its phosphorylation forms in normotensive rats [ 14 ]. Furthermore, to our knowledge, we were the first to report that in the right OB of DOCA-salt hypertensive rats TH activity and expression as well as neuronal norepinephrine release were increased whereas the uptake of the amine was diminished [ 40 ].…”

“…ETs are potent vasoconstrictor substances intimately involved in the regulation of BP and cardiovascular function. In the brain, ETs modulate catecholaminergic transmission, although little is known about their participation in the central regulation of cardiovascular physiology and pathophysiology [ 9 , 10 , 11 , 12 , 13 , 14 , 15 ]. ETs mediate their biological effects through two well characterized G-protein coupled receptors, ET A and ET B [ 10 , 16 , 17 ].…”

“…ETs mediate their biological effects through two well characterized G-protein coupled receptors, ET A and ET B [ 10 , 16 , 17 ]. Several authors support the existence of atypical or non-conventional receptors based on the observation of atypical responses to the ET agonists and antagonists that characterize the conventional receptors [ 13 , 14 , 16 , 18 ]. However, at present no additional ET receptors have been cloned.…”

“…We previously reported that ETs applied to the brain modulate noradrenergic transmission (biosynthesis, neuronal release, and uptake of norepinephrine) in the anterior and posterior hypothalamus as well as in the OB of both normotensive and DOCA-salt hypertensive rats [ 11 , 12 , 13 , 14 , 15 ]. In recent studies, we showed that the acute administration (1 h) of an ET A antagonist (BQ610) or an ET B agonist (IRL1620) in the rat brain lateral ventricle modulates tyrosine hydroxylase (TH) expression and its phosphorylated forms in the anterior and posterior hypothalamus as well in the OB.…”

Endothelins and dopamine levels in tears for assessment of neurovascular disorders in glaucoma

“…Известно, что ДА действует на периферические сосуды как вазодилататор, а ЭТ-1 и big-ЭТкак вазоконстрикторы; следовательно, снижение содержания ДА и его метаболитов и повышение уровня эндотелинов в слезе указывает на усиление вазоконстрикции и нарушение микроциркуляции в тканях глаза. Возможно, эндотелины влияют на концентрацию ДА за счет регулирования активности тирозингидроксилазы (фермента, участвующего в образовании ДА) [24]. Дофаминергическая система выполняет важную роль в глаукоматозном процессе [25].…”