Search results for "Piperazines"

Impact of serotonin 2C receptor null mutation on physiology and behavior associated with nigrostriatal dopamine pathway function.

2009

The impact of serotonergic neurotransmission on brain dopaminergic pathways has substantial relevance to many neuropsychiatric disorders. A particularly prominent role has been ascribed to the inhibitory effects of serotonin 2C receptor (5-HT2CR) activation on physiology and behavior mediated by the mesolimbic dopaminergic pathway, particularly in the terminal region of the nucleus accumbens. The influence of this receptor subtype on functions mediated by the nigrostriatal dopaminergic pathway is less clear. Here we report that a null mutation eliminating expression of 5-HT2CRs produces marked alterations in the activity and functional output of this pathway. 5-HT2CR mutant mice displayed i…

The interferance of muscarinic receptors with the noradrenaline release from sympathetic nerve endings caused by nicotinic agents.

1968

Brimonidine versus dapiprazole: Influence on pupil size at various illumination levels.

2005

To evaluate the influence of dapiprazole versus brimonidine on pupil size at various illumination levels.Department of Ophthalmology, Johannes Gutenberg-University, Mainz, Germany.In randomized prospective study, 19 healthy volunteers received 2 ophthalmic solutions, dapiprazole and brimonidine, 1 in each eye, for intraindividual comparison. Before and after application, pupil diameter was measured using an infrared binocular pupillometer at 3 illumination levels (0.03, 0.82, and 6.4 lux).Only slight pupil dilation was observed under scotopic conditions after application of both agents. After 20 minutes, the median reduction in pupil width was 1.4 mm for brimonidine and 0.9 mm for dapiprazo…

Cigarette smoke-induced pulmonary endothelial dysfunction is partially suppressed by sildenafil.

2009

Abstract Cigarette smoke mediated oxidative stress and endothelial dysfunction are important processes in the pathogenesis of several lung disorders. In this study we evaluated the effect of PDE5 inhibition on pulmonary artery endothelial dysfunction induced by cigarette smoke in vitro . Human pulmonary artery endothelial cells (HPAEC) were incubated in the absence or presence of PDE5 inhibitor sildenafil (10 nM–1 μM), PKG agonist 8-Br-cGMP (1 mM), or the antioxidants dyphenyleneiodonium (DPI 1 μM) and N -acetylcysteine (NAC 1 mM) for 30 min. Then, cigarette smoke extract (CSE) was added for 24 h. CSE (2.5–10%)-induced ROS generation was suppressed by DPI, and partially reversed by sildenaf…

Amphoteric, prevailingly cationic L-arginine polymers of poly(amidoamino acid) structure: Synthesis, acid/base properties and preliminary cytocompati…

2013

A linear amphoteric poly(amidoamino acid), L-ARGO7, is prepared by Michael-type polyaddition of L-arginine with N,N′-methylenebisacrylamide. Chain-extension of acrylamide end-capped L-ARGO7 oligomers with piperazine leads to high-molecular-weight copolymers in which L-arginine maintains its absolute configuration. Acid/base properties of L-ARGO7 polymers show isolectric points of ≈10 and positive net average charges per repeating unit at pH = 7.4 from 0.25 to 0.40. These arginine-rich synthetic polymers possibly share some of the unique biological properties of polyarginine cell-permeating peptides. In vitro tests with mouse embryo fibroblasts balb/3T3 clone A31 show that L-ARGO7 polymers a…