Modulated release

Even more sophisticated control of neurotransmitter release is suggested by the possibility of heteroceptors . These receptors are thought to be located on the terminals of, and to modulate transmitter release from, one type of neuron, but are activated by transmitter released from a different type of neuron (Laduron 1985). For example, noradrenaline has been proposed to modulate release of a wide range of transmitters (e.g. dopamine, 5-HT and glutamate) through activation of a2-heteroceptors on the terminals of each of these different types of neuron. However, one factor that should be borne in mind is that most of the evidence for heteroceptors comes from studies of... 

Rump CL, Bohmann C, Schaible U, Schollhorn J, Limberger N (1995) ajc-Adrenoceptor-modulated release of noradrenaline in human right atrium. Br J Pharmacol 116 2617-2624... 

Transmitter release Many3 Nerve terminal membrane receptors Modulate release... 

Byk, G., Wetzer, B., Frederic, M., Dubertret, C., Pitard, B., Jaslin, G. etal. (2000) Reduction-sensitive lipopolyamines as a novel nonviral gene delivery system for modulated release of DNA with improved transgene expression. J. Med. Chem., 43,4377M387. 

In addition to their functions as presynaptic autoreceptors, 0C2AR can also modulate release of other neurotransmitters (Figure 3). In the CNS, 0C2A and 0C2C receptors inhibit dopamine release in basal ganglia (Bucheler et al. 2002) as well as serotonin secretion in mouse hippocampus and brain cortex (Scheibner et al. 2001a). In the enteric nervous system, the release of acetylcholine as determined by [3H] -choline overflow from tissue slices was selectively inhibited by (X2aAR (Scheibner et al. 2002). 

Sarhan H, Cloez-Tayarani I, Massot O, Fillion MP, Fillion G (1999) 5-HTib receptors modulate release of [3H] dopamine from rat striatal synaptosomes. Naunyn Schmiedeberg s Arch Pharmacol 359 40-7... 

Engelman HS, Anderson RL, Daniele C, MacDermott AB (2006) Presynaptic alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors modulate release of inhibitory amino acids in rat spinal cord dorsal horn. Neuroscience 139 539 Engelman HS, MacDermott AB (2004) Presynaptic ionotropic receptors and control of transmitter release. Nat Rev Neurosci 5 135 45... 

Chien YW. Controlled- and modulated-release drug-delivery systems. In Swarbrick J, Baylan JC, eds. Encyclopedia of Pharmaceutical Technology. New York Dekker, 1999 281-313. 

Sarhan H, Grimaldi B, Hen R, Fillion G. 5-HT1B receptors modulate release of [3H]dopamine from rat striatal synaptosomes further evidence using 5-HT mod-uline, polyclonal 5-HT1B receptor antibodies and 5-HT1B receptor knock-out mice. Naunyn-Schmiedebergs Arch Pharmacol 2000 361 12-18. 

Heller, J., Modulated release from drug delivery devices, Critical Reviews in Therapeutic Drug Carrier Systems, Vol. 10, No. 3, 1993, pp. 253-305. 

Bamford NS, Robinson S, Palmiter RD, Joyce JA, Moore C, et al. 2004. Dopamine modulates release from corticostria-tal terminals. J Neurosci 24 9541-9552. 

Pig. 27. Possible sites for the binding of secondary, nonsynergistic anions, which may perturb the iron site and modulate release. Residue 121 is the essential arginine. Residues 210 and 301 are located behind the iron site, near the Tyr ligands and the hinge region. Numbering is as for the N-lobe of lactoferrin. The identities of these residues, which vary in the two lobes and between different transferrins, can be seen in Table III. 

Several newer phannacological effects, independent of the anticoagulant effects, have been described. These include glycosylation mediated functional modulation of macromolecules, growth factor modulation, release of endothelial products and interactions with various endogenous sites. 

Reduction-sensitive lipopolyamines as a novel nonviral gene delivery system for modulated release of DNA with improved transgene expression. J Med Chem 43 4377-4387... 

Table 1 Reasons for Modulating Release of Drug in the Lungs... 

As indicated in the ganglionic effects of nerve CW agents, a number of mammalian synapses have presynaptic muscarinic autoreceptors that can modulate release of acetylcholine. The concept of presynaptic receptors that can modulate evoked... 

Controlled and modulated release of basic fibroblast growth factor. Biomaterials 12 619-626. 

Receptors on soma, dendrites, and axons of neurons respond to neurotransmitters or modulators released from the same neuron or from adjacent neurons or cells. Soma-dendritic receptors are located on or near the cell body and dendrites when activated, they primarily modify functions of the soma-dendritic region such as protein synthesis and generation of action potentials. Presy-naptic receptors are located on axon terminals or varicosities when activated, they modify functions such as synthesis and release of transmitters. Two main classes c presynaptic receptors have been identified on most neurons, including sympathetic and parasympathetic terminals. Heteroreceptors are presynaptic receptors that respond to neurotransmitters, neuromodulators, or neurohormones released from adjacent neurons or cells. For example, NE can influence the release of ACh from parasympathetic neurons by acting on and receptors, whereas ACh can... 

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