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Query: UNIPROT:P20366 (
substance P
)
21,176
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
The cellular localization of
substance P
/
neurokinin A
-encoding
preprotachykinin
mRNAs in the rat enteric nervous system was studied by means of in situ hybridization histochemistry using 35S- or 3H-labeled single-stranded ribonucleic acid (RNA) probes which recognize all three
preprotachykinin
mRNA species,
alpha, beta
, and gamma.
Substance P
/
neurokinin A
-encoding mRNAs are expressed in neurons within the myenteric plexus of the esophagus and stomach, being more numerous in the latter, and in ganglion cells distributed to both the myenteric and submucosal plexuses of the intestine. Specificity of the hybridization was demonstrated by the lack of specific signal above background in sections incubated with a sense RNA probe or pretreated with ribonuclease A before hybridization. Ribonucleic acid blot hybridization analysis of RNA extracts from both the muscle layer-myenteric plexus and submucosal layer preparations of the duodenum demonstrated a single band of hybridization at 1.3 kb. Solution hybridization-nuclease protection assays showed multiple
preprotachykinin
-encoding transcripts in these RNA extracts, with an abundance level of gamma-mRNA greater than beta-mRNA much greater than alpha-mRNA, which is similar to that observed in the rat brain. Our results indicate that the
preprotachykinin
gene encoding the
tachykinin
peptides,
substance P
and
neurokinin A
, is transcribed in a population of enteric neurons that have a regional distribution comparable to the previously described
tachykinin
-like immunoreactive neurons, suggesting that specific mRNAs and the posttranslationally processed peptides are localized in the same structures.
...
PMID:Expression of substance P/neurokinin A-encoding preprotachykinin messenger ribonucleic acids in the rat enteric nervous system. 247 98
1. The effects of capsaicin, calcitonin gene-related peptide and
substance P
were studied via three parameters in the guinea-pig vas deferens: the overflow of ATP and of tritiated noradrenaline, the mechanical responses to field stimulation and the mechanical responses to exogenous noradrenaline and
alpha, beta
-methylene ATP. 2. At 2 Hz, capsaicin inhibited the stimulus-evoked release of ATP, whereas it was without effect on the release of noradrenaline. At 20 Hz capsaicin did not affect the release of either of the cotransmitters. Capsaicin enhanced responses to
alpha, beta
-methylene ATP, but not to exogenous noradrenaline. 3. Calcitonin gene-related peptide, like capsaicin, inhibited the release of ATP, but not noradrenaline at 2 Hz and was without effect on release at 20 Hz. However, calcitonin gene related peptide inhibited responses to
alpha, beta
-methylene ATP and was without effect on responses to exogenous noradrenaline. 4.
Substance P
had no effect on the release of either noradrenaline or ATP at either frequency. However, like capsaicin it enhanced responses to
alpha, beta
-methylene ATP and was without effect on exogenous noradrenaline. 5. These results suggest that the actions of capsaicin on the guinea-pig isolated vas deferens are mediated via the release of both calcitonin gene-related peptide and
substance P
. Furthermore, as capsaicin and calcitonin gene-related peptide prejunctionally modulate purinergic, but not noradrenergic transmission, this suggests that the mechanisms for the storage and release of the sympathetic co-transmitters noradrenaline and ATP may not be the same.
...
PMID:Modulation of neurotransmission in the guinea-pig vas deferens by capsaicin: involvement of calcitonin gene-related peptide and substance P. 247 44
1. The intracellularly-recorded electrical and mechanical responses to field stimulation of intramural nerves in three sympathetically-innervated smooth muscles--the mouse vas deferens, the rabbit ear artery and the rabbit mesenteric bed preparation were investigated. 2. In each tissue there was evidence for co-transmission involving noradrenaline (NA) and adenosine 5'-triphosphate (ATP) or a closely related nucleotide. 3. The electrical response in each tissue consisted of excitatory junction potentials (ejps) which were abolished by
alpha, beta
-methylene ATP (
alpha, beta
MeATP, 1-10 X 10(-6) M), suggesting that they were mediated by ATP. Only in the rabbit ear artery was there an additional electrical event mediated by NA. This took the form of a small slow membrane depolarization which followed the ejps and which was antagonized by either of the alpha-adrenoreceptor blocking agents phentolamine (1 X 10(-6) M) or prazosin (1 X 10(-7) M). 4. In the mouse vas deferens and rabbit mesenteric artery, both transmitter substances (NA and ATP) played a role in the contractile response to field stimulation. In the rabbit ear artery, NA alone appeared to mediate the contractile event. 5. Contractile responses to nerve-released ATP were accompanied by a membrane potential change, whereas those to NA appeared to be mediated largely by a voltage-independent mechanism. 6. In the mouse vas deferens, the ejps and action potentials evoked by field stimulation appeared to be mediated by a discrete increase in permeability to Na+ and K+. 7. In the mouse vas deferens, local application of bradykinin (1-100 X 10(-7) M) produced a small, slow membrane hyperpolarization. VIP (1-100 X 10(-7) M), neuropeptide Y (1-100 X 10(-7) M),
substance P
(1-100 X 10(-7) M), somatostatin (1-100 X 10(-7) M), leu-enkephalin (1-100 X 10(-7) M), metenkephalin (1-100 X 10(-7) M) and bombesin (1-100 X 10(-7) M), similarly applied, each produced no significant change in membrane potential. None of these peptides appear to be the transmitter mediating the ejp in this tissue.
...
PMID:The electrical and mechanical basis of co-transmission in some vascular and non-vascular smooth muscles. 284 46
Translocation of protein kinase C (PKC) from the cytosol to the plasma membranes is believed to reflect activation of the enzyme. We have studied translocation of PKC in lactotroph-enriched anterior pituitary cell cultures by measuring the incorporation of gamma-32P from [gamma-32P]ATP into a synthetic peptide substrate, MBP4-14, and by immunoblotting of PKC isozymes. Using cells permeabilized with digitonin the effects of PKC cofactors on the distribution of the enzyme were studied. Ca2+ (50 nM) and dioctanoyl-sn-glycerol had no effect when tested alone, but in combination they caused a redistribution of PKC from the soluble to the particulate fraction. Arachidonic acid needed Ca2+ to induce translocation of PKC, while being ineffective under Ca(2+)-free conditions. Western blot analysis of partly purified PKC from lactotroph-enriched pituitary cells revealed the presence of the
alpha, beta
, delta and zeta isozymes. 12-O-Tetradecanoylphorbol 13-acetate (TPA) and
substance P
displayed different patterns of redistribution of PKC isozyme immunoreactivity from soluble to membrane-attached forms. Thus, TPA induced time- and dose-dependent (mean effective concentration (EC50) = 1 nM) translocation of the
alpha, beta
and delta species, while
substance P
stimulated time- and dose-dependent (EC50 = 1 nM) redistribution of the alpha and beta isozymes. zeta subtype immunoreactivity could not be translocated by either agonist; neither could the immunoreactivity of zeta be down-regulated by long-term treatment (24 h) with TPA. The results indicate that simultaneous activation of phospholipases C and A2 induces a synergistic activation of PKC. Finally it is suggested that
substance P
may exert some of its effects in lactotrophs by translocation of PKC isozymes alpha and beta.
...
PMID:Translocation of protein kinase C isozymes in lactotroph-enriched rat anterior pituitary cell cultures: differential effects of substance P and phorbol ester. 752 60
It is generally accepted that the phospholipid and calcium-dependent enzyme protein kinase C (PKC) plays a significant role in secretion of hormones from anterior pituitary cells. The present study was undertaken to study age and sex-related changes in 1. levels of immunoreactivity of PKC isozymes and 2. distribution of immunoreactivity of PKC isozymes after stimulation with
substance P
(SP) in rat lactotroph-enriched cell cultures. The
alpha, beta
, delta and zeta isozymes were present in both sexes and at all ages. There was a sex-specific differential regulation of the different PKC isozymes as a function of sexual maturation. In male rats there was an up-regulation of the alpha isozyme throughout the sexual development, while the beta subtype showed a small, but significant decrease in immunoreactivity with increasing age. In female rats, on the other hand, the beta species was up-regulated with increasing age while the other subtypes remained constant. The concentration of the delta and zeta isozymes was unaffected of sex and age. Stimulation of lactotroph-enriched cell cultures with
substance P
(SP) resulted in translocation of the alpha and beta isozymes from the soluble to the particulate fraction while the delta and zeta species were left unchanged independently of age and sex. However, a decrease in responsiveness was observed in adult male rats, although a significant degree of translocation of alpha and beta species was still detected. On the basis of these results it is suggested that in lactotroph-enriched cell cultures basal levels of PKC subtype immunoreactivity and distribution of immunoreactivity of PKC isozymes after SP challenge might be regulated as a function of sex and age.
...
PMID:Translocation of protein kinase C isozymes in rat pituitary lactotroph-enriched cell cultures by substance P: effects of sex and age. 758 12
1. Intracellular membrane potential recordings were made from circular smooth muscle cells of the guinea-pig ileum in the presence of atropine (1 microM) and nifedipine (0.1 microM) at 30 degrees C. 2. Electrical field stimulation with one or four pulses produced a fast inhibitory junction potential (IJP) which lasted around 1 s. It was abolished by tetrodotoxin (1 microM), apamin (0.3 microM), and
alpha, beta
-methylene ATP tachyphylaxis. 3. Nitric oxide synthase inhibitor N-nitro-L-arginine (L-NNA; 200 microM) had no effect on the resting membrane potential or the fast IJP. 4. Electrical field stimulation in the presence of apamin and
substance P
desensitization produced a slow IJP which was abolished by tetrodotoxin (1 microM). 5. L-NNA significantly reduced the amplitude of the slow IJP (P < 0.01). The antagonistic effect of L-NNA was reversed by L-arginine but not by D-arginine. 6. Injections of
alpha, beta
-methylene ATP, nitric oxide (NO), and vasoactive intestinal polypeptide (VIP) into the recording chamber caused tetrodotoxin-resistant hyperpolarizations of the smooth muscle membrane.
Substance P
desensitization did not modify the amplitudes of the hyperpolarizing response to ATP or NO, but increased the VIP hyperpolarization by 150% (P < 0.01). 7. L-NNA did not modify the amplitude of hyperpolarization due to ATP or NO; however, it antagonized VIP-induced hyperpolarization (P < 0.01). 8. These studies show that in the guinea-pig ileum circular muscle: (a) NO is not involved in the fast IJP which is mediated by ATP; (b) NO is involved in the slow IJP which is mediated by VIP and NO acting in series, and (c) the hyperpolarizing effects of VIP and the slow IJP are normally masked by overlapping depolarization due to concomitant release of
substance P
by the peptide VIP.
...
PMID:Nitric oxide involvement in the peptide VIP-associated inhibitory junction potential in the guinea-pig ileum. 810 1
Smooth muscle cells distributed in the visceral organs are under the control of the autonomic nervous system, and contraction or relaxation of the muscle cells plays an important physiological role in the control of blood pressure, motility of the digestive, respiratory and urinary tracts and secretion. Recent physiological, pharmacological and histochemical investigations indicate that neurotransmitters other than acetylcholine or noradrenaline are involved in peripheral autonomic neuro-effector transmission, and these neurotransmitters are generally termed non-adrenergic, non-cholinergic (NANC) neurotransmitters. The neurotransmitters responsible for excitatory and inhibitory NANC neurotransmission (e-NANC and i-NANC respectively) have not been conclusively identified, but ATP, nitric oxide (NO) and peptides such as VIP and
substance P
are candidates for these roles. In this review, we discuss the possible role of ATP and NO as e- or i-NANC neurotransmitter in the digestive, respiratory and urinary tracts. Much of the work on NANC innervation in the digestive tract has been carried out on the circular muscle layers of the ileum. This receives inhibitory NANC innervation with ATP responsible for fast relaxation and VIP, and possibly NO, for the slow response. Early and late excitatory junction potentials can be recorded in the presence of atropine. The second is due to
substance P
since it is blocked in the presence of spantide and by desensitization of the tissue with high doses of
substance P
. The transmitter responsible for the early NANC contraction has not been identified. Electrical field stimulation (EFS) applied to the tracheal smooth muscle during contraction induced by 5-HT in the presence of atropine and guanethidine elicited monophasic NANC relaxation. By contrast, NANC relaxation elicited in the smaller airways was biphasic, comprising an initial fast component followed by a second slow one. L-NAME selectively abolished the first component without affecting the second. VIP-antagonists or alpha-chymotrypsin considerably attenuated the amplitude of the L-NAME insensitive relaxation. These results indicate that at least two neurotransmitters, possibly NO or NO-containing compounds and VIP, are involved in i-NANC neurotransmission in the airway. In the urinary bladder a large, transient atropine resistant contraction occurs in response to pelvic nerve stimulation. This is blocked by
alpha, beta
methylene ATP suggesting that it is due to ATP. There is no evidence of inhibitory innervation. In the urethra contraction is completely blocked by atropine and guanethidine; a rapid NANC relaxation is abolished by drugs that block NO synthesis. Nerves containing peptides supply both urethra and bladder and may also be involved. These results suggest that all visceral smooth muscles may receive inhibitory NANC innervation involving NO. ATP produces contraction of the urinary bladder but relaxation of the digestive tract. The role of peptides is not yet clear but there is evidence that
substance P
may be an excitatory transmitter and VIP an inhibitory transmitter in many organs.
...
PMID:[The control of smooth muscle tissues by nonadrenergic noncholinergic (NANC) nerve fibres in the autonomic nervous system]. 856 58
Conformationally and configurationally restricted rotameric probes of phenylalanine have been incorporated in the sequence of
substance P
(SP)-Arg-Pro-Lys-Pro-Gln-Gln-Phe-Phe-Gly-Leu-Met-NH2-for analyzing the binding pockets of Phe7 (S7) and Phe8 (S8), in the neurokinin-1 receptor. These analogues of phenylalanine are (2S. 3R)- and (2S, 3S)-indanylglycines, E- and Z-
alpha, beta
-dehydrophenylalanines, and 2(S)-
alpha, beta
-cyclopropylphenylalanines [delta E Phe. delta Z Phe. inverted delta E2 (S) Phe, and inverted delta Z 2 (S) Phe]. Binding data obtained with either conformationally (Ing diastereoisomers) or configurationally (delta E Phe, delta Z Phe) probes have unveiled large differences in the binding potencies of these rotameric probes. With the support of nmr data and energy calculations done on these SP-substituted analogues, we attempt to answer questions inherent to such study. First, none of these six probes prevents the formation of bioactive conformation(s) of the backbone of SP. Second, both diastereoisomers (S, S) and (S, R) of indanylglycine preferentially adopt, in the sequence of SP, the gauche (-) and trans side-chain orientations, respectively, as previously postulated from energy calculations with model peptides. However, in solution, the difference in energy between these rotamers included in the sequence of SP, compared to model peptides, is small since the other rotamer can be detected in [(2S, 3R)Ing7]SP. Finally, from this study we can hypothesize that the large variations observed in the affinities of Phe7 substituted analogues of SP must come from steric hindrance in the S7 binding site, which drastically restricts the space filling around the C alpha-C beta bond of residue 7.
...
PMID:Topographic analysis of the S7 binding subsite of the tachykinin neurokinin-1 receptor. 867 46
1. In the presence of atropine (1 microM), guanethidine (3 microM), indomethacin (3 microM), nifedipine (1 microM), L-nitroarginine (L-NOARG, 100 microM), and the selective
tachykinin
NK1 and NK2 receptor antagonists, SR 140,333 and GR 94,800, respectively (0.1 microM each), a single pulse of electrical field stimulation (EFS) produced a monophasic non-adrenergic non-cholinergic (NANC) inhibitory junction potential (i.j.p., about 10 mV in amplitude) in the circular muscle of guinea-pig proximal colon, recorded by the modified single sucrose gap technique. 2. The P2 purinoceptor agonist,
alpha, beta
methylene ATP (
alpha, beta
mATP, 100 microM) and the pituitary adenylyl cyclase activating peptide (PACAP, 1 microM) both produced hyperpolarization (11 +/- 0.8 mV, n = 14 and 10.2 +/- 0.8 mV, n = 19, respectively) and relaxation (1.1 +/- 0.2 mV, n = 14 and 1.5 +/- 0.2 mN, n = 19, respectively) of the circular muscle. 3. Apamin (0.1 microM) nearly abolished (about 90% inhibition) the NANC i.j.p. and the
alpha, beta
mATP-induced hyperpolarization, markedly reduced the
alpha, beta
mATP-induced relaxation (73% inhibition) and the PACAP-induced hyperpolarization (65% inhibition), while the PACAP-induced relaxation was unaffected. 4. Tetraethylammonium (TEA, 10 mM) increased the EFS-evoked i.j.p. and revealed an excitatory junction potential (e.j.p.). In the presence of TEA,
alpha, beta
mATP induced a biphasic response: transient depolarization and contraction followed by hyperpolarization and relaxation. The hyperpolarization to PACAP was reduced by TEA (45% inhibition) but the relaxation was unaffected. 5. The combined application of apamin (0.1 microM) and TEA (10 mM) abolished the i.j.p. and single pulse EFS evoked a pure e.j.p. with latency three times longer than that of the i.j.p. In the majority of strips tested,
alpha, beta
mATP and PACAP elicited a biphasic response : depolarization and small contraction followed by hyperpolarization and relaxation. 6. The P2 purinoceptor antagonist, pyridoxalphosphate-6-azophenyl-2',4'-disulphonic acid (PPADS) inhibited the NANC i.j.p. in concentration-dependent manner and inhibited the
alpha, beta
mATP-induced hyperpolarization and relaxation, without affecting the hyperpolarization and relaxation induced by PACAP. On the other hand, the P2 purinoceptor antagonist, suramin (100 microM) inhibited to a similar extent (60-80%) the NANC i.j.p. and the hyperpolarization and relaxation induced by
alpha, beta
mATP or PACAP. 7. PPADS and suramin reduced the NANC e.j.p. evoked by a single pulse EFS in the presence of apamin and TEA (100 microM of PPADS and 300 microM of suramin inhibited the e.j.p. by about 40%). 8. We conclude that ATP, but not PACAP, mediates the apamin-sensitive NANC i.j.p. in the circular muscle of the guinea-pig colon. After blockade of the NANC i.j.p., ATP may act as an excitatory transmitter by activating excitatory P2 purinoceptors. The subtypes of P2 purinoceptor involved in the inhibitory and excitatory responses remain to be established. The data suggest that excitatory P2 purinoceptors may be located extrajunctionally.
...
PMID:The possible role of ATP and PACAP as mediators of apaminsensitive NANC inhibitory junction potentials in circular muscle of guinea-pig colon. 892 21
The frequency of spontaneous action potentials of locus coeruleus neurons was recorded extracellularly in pontine slices of the rat brain. The adenosine 5'-triphosphate (ATP) analogues alpha,beta-methylene ATP (alpha,beta-meATP) and 2-methylthio ATP increased the firing rate with a similar potency, while uridine 5'-triphosphate (UTP) was inactive. Diadenosine 5'-pentaphosphate (Ap5A), diadenosine 5'-tetraphosphate (Ap4A) and diadenosine 5'-triphosphate (Ap3A) all facilitated the firing. When equimolar concentrations were compared, Ap5A had the largest effect followed by Ap4A and Ap3A. Suramin markedly inhibited responses to alpha,beta-meATP and 2-methylthio ATP; the effect of Ap4A was only slightly depressed by suramin. Pyridoxalphosphate-6-azophenyl-2,4-disulfonic acid (PPADS) strongly antagonized
alpha, beta
-meATP, but failed to alter the effects of 2-methylthio ATP and Ap4A. Reactive blue 2 weakly antagonized alpha,beta-meATP and did not interfere with 2-methylthio ATP and Ap4A. Moreover, suramin depressed responses to (S)-alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) and N-methyl-D-aspartic acid (NMDA), but not to
substance P
. PPADS failed to affect the AMPA- and NMDA-induced increases in firing. Hence, locus coeruleus neurons may possess receptors for adenosine nucleotides (P2X and P2Y purinoceptors) and dinucleotides (P2D purinoceptors); receptors for uridine nucleotides (P2U purinoceptors or pyrimidinoceptors) are probably absent.
...
PMID:Pharmacological characterization of P2 purinoceptor types in rat locus coeruleus neurons. 898 62
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