The hydroxylase cofactor, tetrahydrobiopterin, and its biosynthetic system are localized in dopaminergic nerve terminals in the striatum. This conclusion is based on the nearly equivalent loss of tyrosine hydroxylase and tetrahydrobiopterin and its initial biosynthetic enzyme, guanosine triphosphate cyclohydrolase, after injection of 6-hydroxydopamine into the substantia nigra. The role of the ...

background and objective: parkinson's disease (pd) is an age-related neurodegenerative disease with selective damage of dopaminergic neurons of the mesencephalon. l-dihydroxyphenylamine (l-dopa) therapy is currently the gold standard maneuver for pd. due to the protective, anti-inflammatory, and antioxidant effect of sesamin, this study was undertaken to assess dose-dependent effect of thi...

Previous results suggest that the tryptophan metabolite, picolinic acid may have the unusual properties of antagonizing the neurotoxic but not the neuroexcitant effects of another tryptophan metabolite, quinolinic acid in the central nervous system. The present experiments tested this possibility utilizing behavioural and tyrosine hydroxylase immunohistochemical techniques. In the first series ...

The purpose of this study was to examine the role of carotid sinus and cardiopulmonary mechanoreceptors in the reflex control of adrenal medullary catecholamine secretion. Afferent input from carotid sinus and cardiopulmonary mechanoreceptors was decreased by carotid occlusion or cervical vagal cold block, respectively. Increases in arterial pressure were significantly greater when either inter...

A selective and permanent destruction of sympathetic ganglia was achieved by injecting 6-hydroxydopamine in newborn animals. A lifelong chemical sympathectomy may thus be obtained. The process of cell damage and destruction is substantially different from that produced with an antiserum to a specific nerve growth factor.

A basic assumption of the 'rotational behavior model' is that amphetamine (AMPH) produces ipsiversive rotational behavior in rats with unilateral 6-hydroxydopamine lesions of the nigrostriatal dopamine (DA) system. However, we report here that if the normally 'dominant ' striatum is partially depleted of DA the majority of rats turn contraversive when given AMPH, i.e. in the opposite direction ...