The effects of microinjections of cholinergic agents into the substantia nigra pars compacta on dopamine (DA) efflux in the anterior dorsomedial striatum of urethane-anesthetized rats were investigated using in vivo chronoamperometry and intracerebral microdialysis techniques. A dose-dependent augmentation of DA efflux as evidenced by increases in the chronoamperometric signals was observed in ...

Prostaglandin E2 (PGE2), similar to beta-adrenergic receptor agonists, can protect airways from bronchoconstriction and resulting increase in airway resistance induced by a number of agents, including cholinergic receptor agonists and antigen. We examined the impact of sustained alterations in PGE2 pathways on changes in airway resistance. Genetic methods were utilized to alter PGE2 metabolism ...

Evidence of an overload of reactive oxygen species and peroxynitrite, a derivative of nitric oxide, in sporadic amyotrophic lateral sclerosis suggests that peroxynitrite could impair cholinergic functions. Because of the impossibility of obtaining synaptosomes from vertebrate neuromuscular junctions, we used cholinergic synaptosomes purified from Torpedo marmorata electroneurons to characterize...

Acetylcholine regulates perfusion of numerous organs via changes in local blood flow involving muscarinic receptor-induced release of vasorelaxing agents from the endothelium. The purpose of the present study was to determine the role of M₁, M₃, and M₅ muscarinic acetylcholine receptors in vasodilation of small arteries using gene-targeted mice deficient in either of the three receptor subtypes...

Organophosphate pesticides are used extensively worldwide, and poisoning by these agents, particularly in developing nations is a public health problem. Organophosphorous nerve agents are still considered as potential threat in both military or terrorism situations. The mechanism of toxicity is the inhibition of acetylcholinesterase, resulting in accumulation of the neurotransmitter acetylcholi...

BACKGROUND Polycyclic aromatic hydrocarbons are suspected developmental neurotoxicants, but human exposures typically occur in combination with other neurotoxic contaminants. OBJECTIVE AND METHODS We explored the effects of benzo[a]pyrene (BaP) on neurodifferentiation in PC12 cells, in combination with a glucocorticoid (dexamethasone, used in preterm labor), an organophosphate pesticide (chlo...

The subfornical organ (SFO) is sensitive to both ANG II and ACh, and local application of these agents produces dipsogenic responses and vasopressin release. The present study examined the effects of cholinergic drugs, ANG II, and increased extracellular osmolarity on dissociated, cultured cells of the SFO that were retrogradely labeled from the supraoptic nucleus. The effects were measured as ...

The hippocampal slice preparation was used to classify cholinergic effects in terms of muscarinic receptor subtypes (M1 or M2) and biochemical effector systems linked to these effects in CA1 pyramidal cells. Based on the action of the M1 antagonist pirenzepine and the M2 antagonist gallamine, the muscarinic-induced membrane depolarization and blockade of the afterhyperpolarization appear to res...

BACKGROUND In light of the large number of chemicals that are potential developmental neurotoxicants, there is a need to develop rapid screening techniques. OBJECTIVES We exposed undifferentiated and differentiating neuronotypic PC12 cells to different organophosphates (chlorpyrifos, diazinon, parathion), a carbamate (physostigmine), an organochlorine (dieldrin), and a metal (divalent nickel;...

Background: Gastric lavage (GL) is one of the most commonly used decontamination method for cholinergic insecticide ingestion in developing countries despite lack of supporting evidence. This study was designed to evaluate the outcome of patients with cholinergic insecticide poisoning treated with GL in regards to timing and frequency of the procedure. Methods: In this prospective observational...