Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P20366 (substance P)
 21,176 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The present study tested whether release of dopamine from isolated bovine adrenal medullary cells in culture could be stimulated or inhibited by secretagogues and modulators known to affect noradrenaline and adrenaline release from adrenal medullary chromaffin cells. K+ depolarization or activation of voltage-sensitive Na+ channels by veratridine both stimulated dopamine release. Ca2+-dependent dopamine release was also stimulated by the mixed nicotinic-muscarinic agonist, carbachol. Carbachol-induced dopamine release was inhibited by a nicotinic but not by a muscarinic antagonist and dopamine release was also stimulated by a selective nicotinic agonist, 1,1-dimethyl-4-phenyl-piperazinium. Carbachol-induced dopamine release was inhibited by substance P and by neuropeptide Y. Histamine also stimulated dopamine release, while angiotensin II and glutamate produced no significant stimulation of dopamine release. Noradrenaline and adrenaline were released in response to the above agents with a profile almost identical to that of dopamine. The results indicate that dopamine can be directly released from adrenal medullary cells in response to stimulation of those cells and suggest that the dopamine release originates from chromaffin cells similar or identical to those storing noradrenaline and adrenaline. A possible role for dopamine, released from adrenal chromaffin cells, in modulating catecholamine release from the chromaffin cells and/or contributing to circulating plasma dopamine is discussed.
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PMID:Dopamine release from bovine adrenal medullary cells in culture. 169 90

The effects of dorsal root stimulation and of substance P (SP), neurokinin A (NKA), and calcitonin gene-related peptide (CGRP) on the basal release of 9 endogenous amino acids, including glutamate (Glu) and aspartate (Asp), have been investigated using the rat spinal cord slice-dorsal root ganglion preparation and high-performance liquid chromatography with fluorimetric detection. High-intensity repetitive electrical stimulation of a lumbar dorsal root produced a Ca2(+)-dependent increase in the basal release of Asp, Glu, glycine (Gly), serine (Ser), and threonine (Thr). Low concentrations of SP (2 x 10(-7) M) caused a selective increase in the rate of basal release of Glu, whereas higher concentrations (1-5 x 10(-6) M) produced, in addition, an increase in the basal release of Asp. The SP-induced increase of Glu persisted in the absence of external Ca2+, but the effect was blocked by (D-Arg1, D-Pro2, D-Trp7,9, Leu11)-SP, an SP analog claimed to be an antagonist of the synthetic SP. NKA (5 x 10(-7) - 10(-6) M), a related tachykinin coexpressed with SP in primary sensory neurons, enhanced the basal release of Gly. CGRP (10(-7) M) caused a significant, largely Ca2(+)-independent increase in the basal release of Glu and Asp and a decrease in asparagine. SP and CGRP potentiated the electrically evoked release of Glu and Asp. Neonatal capsaicin treatment did not significantly alter the basal efflux of 9 endogenous amino acids from the spinal slices, but it prevented the dorsal root stimulation-evoked release of Asp, Glu, Gly, and Thr and the SP-induced increase in the basal release of Glu. However, the effect of CGRP was not significantly modified by the capsaicin treatment. These results indicate that tachykinins (SP and NKA) and CGRP are capable of modulating the basal and electrically evoked release of endogenous Glu and Asp, and these actions may provide an important mechanism by which the peptides contribute to the regulation of the primary afferent synaptic transmission. The enhancement of the basal and the dorsal root stimulation-evoked release of Glu and Asp by tachykinins and CGRP may have important physiological implications for strengthening the synaptic connections in the spinal dorsal horn.
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PMID:Tachykinins and calcitonin gene-related peptide enhance release of endogenous glutamate and aspartate from the rat spinal dorsal horn slice. 169 54

1. The pharmacological profile of a tachykinin antagonist, [D-Arg1, D-Trp7,9, Leu11] substance P (spantide), was studied on motoneurones of the isolated spinal cord of the newborn rat. For this purpose, potentials were recorded from a lumbar ventral root extracellularly and drugs were bath-applied in the presence of tetrodotoxin (TTX). 2. Neurokinin A (NKA), a NK2-receptor selective agonist, induced concentration-dependent depolarizations, which were antagonized by spantide. Analyses of concentration-response curves suggested a competitive type antagonism with a pA2 of 6.5. 3. Depolarizations induced by acetyl-Arg6-septide, a NK1-receptor selective agonist, were also antagonized by spantide with a pA2 of 6.5. 4. Spantide (0.5-16 microM) had no depolarizing action on the ventral root in the presence of TTX. 5. Spantide antagonized the depolarizing action of substance P (SP) when SP was applied at low concentrations (0.1-0.3 microM) or by short duration pulses in artificial cerebrospinal fluid containing TTX, but much higher concentrations of spantide (4-10 microM) were needed to exert an antagonistic action against SP than against acetyl-Arg6-septide or NKA. 6. Thyrotrophin-releasing hormone, L-glutamate, GABA, and noradrenaline, also induced depolarizations of the ventral root in the presence of TTX but the responses to these agonists were not depressed by spantide (16 microM). 7. These results suggest that there is a subtype of tachykinin receptors on neonatal rat spinal motoneurones to which NKA, acetyl-Arg6-septide and spantide bind competitively with high affinity. The present results also suggest the existence on rat motoneurones of another class or other classes of tachykinin receptors that are less sensitive to the antagonistic action of spantide.
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PMID:Pharmacological profile of a tachykinin antagonist, spantide, as examined on rat spinal motoneurones. 169 96

A depletion of large cholinergic neurons in the nucleus basalis of Meynert is a consistent finding in Alzheimer's disease (AD). The nucleus basalis of Meynert also contains interneurons and afferents that may modulate its functioning. In the present study we examined neurochemical markers for neuropeptides, amino acid neurotransmitters, and monoaminergic neurotransmitters in postmortem samples of the nucleus basalis in 16 control subjects and 30 patients with AD. There were no significant changes in glutamate, aspartate, taurine, gamma-aminobutyric acid (GABA), and catecholamines; however, concentrations of serotonin, 5-hydroxyindoleacetic acid, and 5-hydroxytryptophol were significantly reduced. Choline acetyltransferase activity was significantly reduced, consistent with previous reports. Galanin immunoreactivity was significantly increased twofold in the patients with AD, but there were no significant changes in substance P, somatostatin, or neuropeptide Y immunoreactivity. Since galanin inhibits acetylcholine release, and produces cognitive deficits in animals, increased galanin immunoreactivity in the nucleus basalis of Meynert in AD may contribute to the cognitive deficits that characterize the illness.
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PMID:Galanin immunoreactivity is increased in the nucleus basalis of Meynert in Alzheimer's disease. 169 71

The volume-evoked micturition reflex (VEMR) is under the control of a complex vesico-spino-bulbo-spino-vesical reflex arc. When functional this system provides for the storage and retention of urine and its subsequent efficient expulsion by virtue of a joint contraction of the bladder and synergic relaxation of the urethral sphincter. Transection of the spinal cord results in an initial disruption of this organization (areflexia) followed by a time-dependent change in the characteristics of the functioning of this reflex system. The growth of knowledge of the pharmacology of spinal systems has yielded considerable information on the potential spinal neurotransmitter systems and their associated receptors. Given the possible role of such systems in mediating and modulating the VEMR, a reasonable approach has been to investigate the effects of spinally administered agonists and antagonists in unanaesthetized animals in which the VEMR can be examined. Thus, it appears that the initial state of bladder distension is signalled by larger (A type) afferent fibres. After spinal injury and the loss of this supraspinal control, smaller unmyelinated C fibres play a predominant role in controlling this reflex. On stimulation these C fibres release peptides (VIP, CCK, substance P, CGRP) and excitatory amino acids (glutamate). Studies in this laboratory have shown that whereas administration of these peptides is without effect in normal intact rats, the antagonists for glutamate and VIP receptors (but not CCK) produce a dose-dependent increase in spontaneous bladder contractions with a corresponding decrease in the volume required to evoke a VEMR. Other spinal systems, such as those for opioids and GABA, are known to exert modulatory effects upon spinal somatomotor reflex arcs. In the spinal cord these agonists (mu/delta and GABAA/B) produce discrete changes in the VEMR in intact and spinally transected animals. Thus these studies may provide insight into the coordinated mechanisms which govern the VEMR and may also allow the development of pharmacological approaches to managing the dysfunctional bladder.
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PMID:The spinal pharmacology of urinary function: studies on urinary continence in the unanaesthetized rat. 169 10

Using in vivo microdialysis in the dorsal spinal cord of the rat, we have previously observed increases in glutamate and aspartate during exposure to a noxious stimulus. The present investigation was designed to determine whether these increases may be mediated by substance P. Infusion of 1 mM of substance P in the dialysis fluid increased the concentrations of glutamate and aspartate, similar to the response seen during noxious stimulation. In addition, substance P also increased the concentrations of the inhibitory amino acids glycine and taurine. Calcitonin gene-related peptide, previously shown to enhance substance P-induced biting and scratching behavior, produced no effect on amino acid release by itself but potentiated the apparent release of taurine by substance P. To assess the importance of substance P-induced amino acid release in sensory processing, we examined the influence of taurine and of excitatory amino acid antagonists on the biting and scratching behavior produced by excitatory amino acids and substance P. Taurine selectively inhibited only substance P-induced biting and scratching while excitatory amino acid antagonists inhibited only excitatory amino acid-induced behavior. To further explore the ability of taurine to inhibit the substance P-induced behavior, 3 tests of nociception were then used. Pretreatment with taurine inhibited the nociceptive-related writhing behavior produced by an intraperitoneal injection of acetic acid in mice but failed to alter the latency of response in the hot plate or tail flick assay.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Interactions between substance P, calcitonin gene-related peptide, taurine and excitatory amino acids in the spinal cord. 170 Mar 56

We studied the ultrastructure and the synaptic arrangement of glutamate-immunoreactive terminals in rats, in the superficial laminae of the spinal cord, the brainstem cuneate nucleus, and the thalamic ventroposterolateral nucleus, where a role for glutamate as neurotransmitter has been suggested by biochemical, physiological and pharmacological approaches. The antiserum employed was raised against glutaramate conjugated to keyhole limpet hemocyanin with glutaraldehyde, and was used for pre-embedding staining with an avidin-biotin-peroxidase method and for post-embedding staining with an immunogold procedure. Both methods yielded similar results, consisting of labeling of selected terminals in all the areas examined. Double immunogold labeling on the same thin section using antisera against gamma-amino-butyric acid (GABA) or substance P (SP), in combination with the anti-glutamate serum, showed that staining for glutamate and GABA was present in different terminals in all the regions examined; glutamate and SP were co-localized in a few terminals only in the superficial laminae of the spinal cord. By performing immunogold staining in combination with anterograde tracing, glutamate immunoreactivity could be localized in identified primary afferents to the dorsal spinal cord and cuneate nucleus, and in lemniscal afferents to the thalamus.
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PMID:Ultrastructural immunocytochemical localization of excitatory amino acids in the somatosensory system. 170 56

The whole-cell patch-clamp technique was used to examine the effect of substance P (SP) on glutamate-induced currents in freshly dissociated rat spinal dorsal horn neurons (LI-III). In 48% of examined cells SP (10(-10)-10(-6) M) at -70 mV, induced in inward current that desensitized in the continued presence of SP. When applied simultaneously with, or prior to L-glutamate, SP caused a potentiation of L-glutamate-induced current in 65% of the tested cells. Since glutamate activates both N-methyl-D-aspartate (NMDA) and non-NMDA receptors in rat dorsal horn neurons, selective agonists, kainate, quisqualate, alpha-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid (AMPA) and NMDA were used to determine which subtype of excitatory amino acid receptors interacted with SP. We found that the responses to quisqualate, kainate, and AMPA were not significantly affected by SP (less than 20% increase). In contrast, the inward currents induced by NMDA (30-300 microM) appear to be reduced and potentiated after the administration of 2-200 nM of SP. These results suggest that post-synaptic mechanisms of action of tachykinins may contribute to the regulation of the strength of glutamate-mediated excitatory transmission in the rat spinal dorsal horn.
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PMID:Substance P modulates glutamate-induced currents in acutely isolated rat spinal dorsal horn neurones. 170 17

The levels of extracellular striatal dopamine and glutamate were measured simultaneously in halothane-anaesthetized rats using microdialysis. Unilateral injections of substance P (0.07 nmol) into the substantia nigra, pars reticulata enhanced the levels of dopamine and glutamate in the ipsilateral striatum. Intranigral injections of neurokinin A (0.09 nmol) enhanced the levels of striatal dopamine, and intranigral injections of gamma-aminobutyric acid (300 nmol) or dynorphin A (0.5 nmol) decreased the levels of striatal dopamine, but none of these had any effect on the levels of striatal glutamate. Local perfusion with the dopamine agonists apomorphine (D1/D2), SKF 38393 (D1) or pergolide (D2) (each at 10(5) M) decreased the levels of striatal dopamine and enhanced the levels of striatal glutamate. In unilateral 6-hydroxydopamine-lesioned rats, basal striatal glutamate levels were decreased bilaterally. Furthermore, on the denervated side intranigral substance P stimulation of striatal glutamate levels was enhanced, while on the intact side intranigral substance P stimulation of striatal dopamine and glutamate levels was similar to that seen in normal rats. These findings suggest that striatonigral substance P provides a stimulatory regulation of ipsilateral striatal glutamate release. Furthermore, it is indicated that striatal glutamate release can also be regulated by dopamine terminals.
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PMID:Striatal dopamine and glutamate release: effects of intranigral injections of substance P. 170 11

As microinjection of either substance P (SP) or acetylcholine (ACh) into the right intermediolateral cell nucleus (IML) at the T2 level elicits increases in heart rate (HR) in the anesthetized rat, we investigated the possibility of a synergistic effect on HR and arterial pressure (AP) of ACh and SP microinjected in this nucleus. Moreover, we studied the effect on HR and AP of microinjection of either ACh or SP into the IML combined with activation of cardiovascular neurons in the ipsilateral rostral ventrolateral medulla (RVLM) by microinjection of glutamate (Glu). Male Wistar rats (n = 16) were anesthetized with urethane (1.4 g/kg i.p.), artificially ventilated, and the dorsal medulla and spinal cord (T1-T3) were exposed. Micropipettes containing SP and ACh were positioned in the right IML at the T2 level. Microinjection of threshold amounts of ACh (5 x 10(-2) M, 2-10 nl) and SP (3 x 10(-6) M, 2-10 nl) that caused small or no changes in HR or AP (less than 10 bpm or mmHg) elicited statistically significant synergistic increases in HR (22.9 +/- 3.3 bpm) but no changes in AP. Threshold microinjections of Glu (0.18 M, 2-10 nl) into the right RVLM combined with microinjections of threshold amounts of SP or ACh into the ipsilateral IML elicited significant synergistic increases in HR of 13.1 +/- 1.9 bpm and 10.6 +/- 1.9 bpm and in AP of 9.7 +/- 1.9 mmHg and 10.8 +/- 1.7 mmHg, respectively. These results indicate that SP and ACh interact to influence cardioacceleratory spinal preganglionic neurons (SPN) and interact with the transmitter released in the IML by RVLM stimulation to elicit increases in HR.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Cardiovascular responses to combined microinjection of substance P and acetylcholine in the intermediolateral nucleus of the rat. 170 92


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