Neuropeptide release

Huybrechts, J., De Loof, A., and Schools, L., Melatonin-induced neuropeptide release from isolated locust corpora cardiaca. Peptides 26(1), 73-80, 2005. 

Ludwig M, Sabatier N, Bull PM, Landgraf R, Dayanithi G, Leng G (2002) Intracellular calciimi stores regulate activity-dependent neuropeptide release from dendrites. Natiue 418 85-89... 

Because neuropeptides have a more discrete neuroanatomical localization than classical neurotransmitters, it is expected that they produce less disturbances of physiological processes if modulated by drugs and antagonists are suggested to be less likely to produce tolerance or dependency. Additionally, these drugs are not expected to disrupt normal physiology in the absence of neuropeptide release, i.e., activation of the system. 

Trigeminal sensory nerve activation Neuropeptide release... 

Another interesting effect related to H3 receptors is its possible interference in the airway microvascular leakage (AML) induced by a variety of stimuli. Activation of H3 receptors inhibits NANC-induced leakage by reducing neuropeptides release from sensory fibers (Ichinose et al., 1990). Hence, H3 receptors may act as a safety device in asthmatic diseases to prevent, not only bronchoconstriction, but also increased airway permeability. On the other hand, it was also demonstrated that H3 receptor activation inhibits sympathetic tone, which, in turn, reduces antigen-induced AML (Danko et al., 1994). Therefore, the authors conclude that the blockade of H3 receptors may have therapeutic potential in inflammatory pulmonary... 

Rat Lung (in vitro) 4 Neuropeptide release from sensory nerves Dimitriadou et al, 1994... 

Blockade of histamine autoreceptors increases histamine synthesis and release and may support higher CNS functions such as arousal, cognition and learning. Peripheral histamine heteroreceptors on C liber and on postganglionic sympathetic fiber terminals diminish neuropeptide and noradrenaline release, respectively. Both inhibititory effects are beneficial in myocardial ischemia. The inhibition of neuropeptide release also explains the antimigraine effects of some agonists of presynaptic histamine receptors. 

In myocardial ischemia, several of the mechanisms presented above come into play. First, neuropeptides such as CGRP are released from cardiac sensory C fibers and subsequently release histamine from mast cells as just mentioned. Histamine then can act at least at two presynaptic H3 heteroreceptors on the C fibers to attenuate further neuropeptide release (Section 3.9), and on postganglionic sympathetic fibers to attenuate exocytotic as well as carrier-mediated noradrenaline release (Section 3.3). Both presynaptic effects are potentially beneficial. The H3 receptors are unique in this pattern of effects. Presynaptic adenosine Ai receptors, when activated, also inhibit both exocytotic and carrier-mediated noradrenaline release, but cardiac Ai receptors in addition mediate negative chronotropic and dro-motropic effects. Presynaptic 0C2-adrenoceptors, when activated, reduce exocytotic noradrenaline release but enhance carrier-mediated noradrenaline release (due to stimulation of the Na+/H+ exchanger, Imamura et al. 1996b), which is the major mode of noradrenaline release and the major arrhythmogenic risk in protracted myocardial ischemia (see Levi and Smith 2000 Koyama et al. 2003). 

Ahluwalia J, Urban L, Bevan S, Nagy I (2003) Anandamide regulates neuropeptide release from capsaicin-sensitive primary sensory neurons by activating both the cannabinoidl receptor and the vanilloid receptorl in vitro. Eur J Neurosci 17 2611-18... 

DA control of anterior pituitary hormone secretion also mediated through transynaptic regulation of hypothalamic neurosecretory neurons. This occurs via axonal-somatic/ dendritic interactions in hypothalamic regions containing neurosecretory neuron perikarya and/or through axonal-axonal interactions on their terminals in the median eminence. Diencephalic DA neurons may regulate neuropeptide release directly via stimulatory Di or inhibitory D2 receptors located on hypothalamic neurosecretory neurons, or they may act indirectly through stimulatory and/or inhibitory interneurons. 

Piedimonte, G., Hoffman, J.I.E., Husseini, W.K. etal. (1992). Effect of neuropeptides released from sensory nerves on blood flow in the rat airway microcirculation. J. Appl. Physiol. 72, 1563-1570. 

Helyes Z, Nemeth J, Than M, Bolcskei K, Pinter E, Szolcsanyi J (2003) Inhibitory effect of anandamide on resiniferatoxin-induced sensory neuropeptide release in vivo and neuropathic hyperalgesia in the rat. Life Sci 73 2345-2353... 

Nemeth J, Helyes Z, Than M, Jakab B, Pinter E, Szolcsanyi J (2003) Concentration-dependent dual effect of anandamide on sensory neuropeptide release from isolated rat tracheae. Neurosci Lett 336 89-92... 

Finally, cannabinoids inhibit the release of neuropeptides like calcitonin gene-related peptide (CGRP), substance P and somatostatin from sensory neurons (Table 4). Capsaicin or electrical stimulation was used to evoke neuropeptide release. In some of these studies, the endocannabinoid anandamide was used, which has a dual effect on neuropeptide release from sensory neurons. Anandamide possesses an inhibitory effect mediated via CBi receptors at low concentrations and... 

Peripheral CBIR Modulation of Capsaicin-Evoked Neuropeptide Release... 

Zolmitriptan is a serotonin 5-HTi-receptor antagonist that is a selective agonist for the vascnlar serotonin (5-HT)-receptor subtype, causing vasoconstriction of cranial arteries and inhibition of proinflammatory neuropeptide release. It is indicated in the short-term treatment of migraine attacks with/without aura. 

---