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

Vasomotor reactivity of human pial veins, obtained in conjunction with neurosurgical operations, was studied in vitro. The effect of transmitters in nerves previously recognized in these vessels, as well as that of neuromodulators, was characterized. A comparison of these effects with their effects in the nearby pial arteries of the same patients was made. It was found that the veins were equipped with more sensitive alpha-adrenergic receptors (lower EC50 values) than the arteries. The reverse was found for 5-hydroxytryptamine. Acetylcholine, which causes an endothelium-dependent dilation of pial arteries, contracted the veins despite an apparently intact endothelium. Considering the lower maximum values in veins, responses to histamine, the neuropeptides calcitonin gene-related peptide, bradykinin, and neuropeptide Y; and prostaglandins (PGE1 and PGF2 alpha) were principally the same in the arteries and veins. The dilatory responses to vasoactive intestinal polypeptide and substance P were less pronounced in veins than in arteries. The veins only transiently contracted to a depolarizing potassium solution; calcium influx promotors and inhibitors, as well as calcium-free solution, did not affect the contractile ability of the vein, contrasting to the reactivity of the artery. This clearly indicates that the veins are not substantially dependent upon calcium influx for their acute contractile ability.
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PMID:Vasomotor effects of neurotransmitters and modulators on isolated human pial veins. 288 77

1 Various doses of mediators were tested on tracheal vascular resistance in dogs anaesthetized with pentobarbitone. Tracheal vascular resistance was determined by perfusing the cranial tracheal arteries at constant flows and measuring inflow pressures. 2 All drugs produced dose-related changes in vascular resistance. 3 The peptides bradykinin, substance P and vasoactive intestinal peptide (VIP) each had similar vasodilator potencies and were much more powerful than histamine, methacholine and salbutamol. 4 Platelet activating factor (Paf) was a weaker dilator than the peptides. Prostaglandins D2, E1 and F2 alpha had wide dilator potency ranges, PGE1 being very effective even at low concentrations. 5 Phenylephrine, an alpha-adrenoceptor agonist, was the only drug tested that always increased vascular resistance. 6 All the drugs studied also had effects on the contralateral tracheal vascular resistance.
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PMID:Dose-related effects of pharmacological mediators on tracheal vascular resistance in dogs. 342 76

The bronchial arteries extend to all lung structures in man with the exception only of the alveolar wall. In addition to providing nutrition to the lungs, the bronchial vessels can also function as a hemodynamic and gas-exchange system due to anastomoses with the pulmonary arteries; they also play a significant role in controlling the clearance of chemical mediators, regulating the development of airway wall edema, and controlling heat exchange in the tracheobronchial tree. We have measured the effects of inflammatory and other mediators on tracheal mucosal thickness and the changes in tracheal vascular resistance in dogs. Bradykinin, histamine, and methacholine had large "vasodilator" effects, decreasing vascular resistance, and they also clearly increased the thickness of the mucosa. Substance P, VIP, PGF2 alpha, and PGE1 had as large a response on vascular resistance as the drugs mentioned above, but only had small effects in increasing tracheal mucosal thickness. Salbutamol fell between these 2 groups with regard to the pattern of response. Phenylephrine had an opposite action, causing an increase in vascular resistance and a decrease in mucosal thickness. Despite the vasodilatation and the increase in vascular permeability due to vasoactive drugs, the changes in mucosal thickness were rather small and could not be correlated with the decreases in vascular resistance due to the different drugs. Such changes are unlikely to have an appreciable effect on tracheal airway resistance. The change in mucosal thickness may be more significant in those parts of the airways where the ratio of change in mucosal thickness to the radius of adjacent lumen is large, such as the nose and small conducting airways.
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PMID:Effects of inflammatory and other mediators on airway vascular beds. 359 20

The effects of pharmacological and nervous stimuli on the flow of secretion from the dog lateral nasal gland following catheterization are described. Drugs were injected close-arterially into the arterial supply to the nose, or intravenously. Cholinergic agonists (pilocarpine, methacholine), given intravenously (I.V.) or intra-arterially (I.A.), and stimulation of the vidian nerve produced a copious flow of secretion which was blocked by atropine. The adrenoceptor agonists phenylephrine (alpha) and salbutamol (beta 2), given I.V. or I.A., and stimulation of the vagosympathetic nerve produced a small but consistent flow of secretion. Histamine (50 micrograms), substance P (0.1 micrograms) and prostaglandin E1 (1-5 micrograms), injected I.A., produced small flows of secretion. Bradykinin (25 ng-50 micrograms), 5-hydroxytryptamine (100 ng-50 micrograms) and vasoactive intestinal peptide (VIP) (10 ng-50 micrograms) did not cause secretion. The total protein content, the composition of secretions as revealed by sodium dodecyl sulphate-polyacrylamide agarose gel electrophoresis, and changes in [Na] and [K] in relation to flow of secretion are described. Differences in ion and protein concentrations, and in protein composition, are described for vidian nerve-induced and vagosympathetically induced secretions. Electron microscopy revealed that the gland contains serous cells in the secretory region, and ducts morphologically similar to the intercalated, striated and excretory ducts of salivary glands.
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PMID:Lateral nasal gland secretion in the anaesthetized dog. 374 94

1 Six to eight days after diathermic destruction of the fifth cranial nerve in the rabbit, the ocular hypertensive and miotic responses to intracameral administration of capsaicin, bradykinin, and prostaglandin E1 were greatly reduced or completely abolished. The response to substance P was not abolished. 2 A response could still be obtained to chemical irritants 36 h after coagulation of the nerve and it is deduced that manifestation of the response is dependent upon functional sensory nerve terminals, and is independent of central connections. 3 It is suggested that prostaglandin E1 and bradykinin act directly upon the sensory nerve endings and that propagation of the response is augmented by axon reflex. 4 In view of the ability of substance P to induce miosis in the denervated eyes, it is presumed that its actions are not mediated via sensory nerves. 5 It is considered possible that the mediator(s) released from sensory nerve endings after chemical irritation or antidromic stimulation may act in the same way as substance P with regard to the miotic effect. 6 Synthetic substance P will only produce ocular hypertension in doses which induce a maximal miotic response. This may either be a question of access or a partial resemblance to the endogenous mediator.
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PMID:The effects of sensory denervation on the responses of the rabbit eye to prostaglandin E1, bradykinin and substance P. 615 34

The effective doses of substance P, bradykinin and prostaglandin E1 that induced depressor responses in rats and rabbits were compared. On molar conversion substance P showed the most pronounced activity. There was an essential difference in doses that evoked standard responses in rabbits (the preparations were administered into the right or left heart ventricle). For bradykinin the dose difference was fivefold and prostaglandin E1 twenty-twofold. Substance P did not undergo inactivation in the lungs.
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PMID:[Hemodynamic characteristics of polypeptide substance P compared to bradykinin and prostaglandin E1]. 615 17

The role of nerve conduction was studied in acute experimental uveitis caused by antidromic trigeminal nerve stimulation, prostaglandin E1 and E2 (PGE1 and PGE2), capsaicin and substance P (SP). Systemic indomethacin was used to prevent formation of endogenous prostaglandins, and intracameral injection of tetrodotoxin (TTX) was used to block nerve conduction. 10 micrograms TTX prevented the miosis and reduced the rise in intraocular pressure (IOP) usually caused by antidromic trigeminal nerve stimulation. At a low dose of PGE1 the IOP rise was blocked by TTX. At higher doses of PGE1 and PGE2 the pressure effect was not blocked by TTX; the miotic effect was markedly diminished. Capsaicin caused a rise in IOP that was almost totally blocked by TTX, while the miosis at high doses seemed unaffected. At low doses, capsaicin-induced miosis could be abolished by TTX. SP caused miosis in TTX treated eyes similar to that in untreated eyes; the IOP rise was delayed by TTX. The results indicate that nerve conduction plays a role in the IOP reaction caused by low doses of PGE1 and by capsaicin and SP. The mechanism suggested is an axon reflex, elicited in the anterior uvea and resulting in transmitter release in the ciliary processes. Nerve conduction with release of SP or a similar substance in the iris seems to be required for the miotic effects of PGE1 and PGE2. SP and capsaicin are similar in not requiring nerve conduction to cause miosis, but the capsaicin effect probably requires presence of nerves, since denervated eyes--which respond to SP--have been reported no to respond to capsaicin does similar to those used here.
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PMID:Ocular responses to antidromic trigeminal stimulation, intracameral prostaglandin E1 and E2, capsaicin and substance P. 617 Feb 10

1 Nerve growth factor (NGF), substance P (SP) and thymopoietin all caused shape change reactions of rapid onset in rabbit platelets. NGF had the highest maximal effect, and SP the lowest EC50 (concentration causing half maximal shape change). The action of SP was reversible within 5 min, whereas that of NGF lasted for at least 1 h. A series of other peptides were inactive. 2 After preincubation of platelets with SP, a second application of SP no longer caused a shape change reaction, whereas the effect of NGF was not influenced. 3 An oxidized NGF-derivative without biological activity did not cause a shape change reaction, neither did epidermal growth factor. 4 Prostaglandin E1 (PGE1) and pretreatment of the platelets with 3% butanol, which counteract the shape changes caused by 5-hydroxytryptamine (5-HT) and adenosine 3',5'-diphosphate, also antagonized those induced by NGF and SP. Neither heparin nor methysergide, an antagonist of 5-HT-receptors, influenced the shape change induced by NGF or SP. The action of NGF was also antagonized by a specific antibody to NGF. 5 Thymopoietin, like the basic polypeptide polyornithine (mol. wt. 40,000) was not antagonized by PGE1 and butanol. Heparin, which counteracted the effect of polyornithine, did not influence that of thymopoietin. 6 In conclusion, different modes of action are involved in the shape change of blood platelets induced by polypeptides and proteins. SP and NGF may act by stimulating specific membrane receptors.
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PMID:Shape changes induced by biologically active peptides and nerve growth factor in blood platelets of rabbits. 617 Mar 75

Peptide and non-peptide agents were tested for their stimulatory or inhibitory effects on circular strips of guinea pig isolated tracheae. Substance P, eledoisin, physalaemin, neurotensin, angiotensin, histamine and carbachol were found to contract, while noradrenaline, dopamine, bradykinin, nucleotides (AMP, ADP, ATP) and prostaglandins (PGE1, PGE2, PGA2) induced concentration-dependent relaxations of tracheae contracted with substance P or carbachol. Indomethacin (2.8 X 10(-6) M) significantly potentiated the effect of substance P and blocked that of bradykinin. The contractions to substance P of tissues treated with indomethacin were not modified by atropine, methysergide, diphenhydramine, cimetidine, propranolol, phentolamine, [Leu8]-ATII, [Leu8]-des-Arg9-bradykinin, naloxone and baclofen. The order of potency of C-terminal fragments of substance P was: hexa(6-11) greater than hepta(5-11) greater than substance P greater than = octa(4-11). It is concluded that the guinea pig isolated trachea is a pharmacological preparation sensitive to numerous agents and useful for studying structure-activity relationship and the mechanism of cellular action of several peptides, particularly substance P.
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PMID:Pharmacological effects of peptides on tracheal smooth muscle. 618 32

A substance P analogue, (D-Pro2, D-Trp7,9)-SP, has been described to have SP antagonistic and SP agonistic effects in different tissues. We have investigated the effects of (D-Pro2, D-Trp7,9)-SP on the sphincter pupillae muscle, the blood aqueous barrier (BAB) and the intraocular pressure (IOP) in the albino rabbit eye. We also investigated the modifying effects of (D-Pro2, D-Trp7,9)-SP on miosis, BAB damage and IOP rise caused by SP, prostaglandin E1 (PGE1), capsaicin and on the miosis caused by electrical intracranial antidromic trigeminal nerve stimulation (NV stim). Endogenous PG synthesis was inhibited by systemic indomethacin i.v., cholinergic influence on the pupil size was inhibited with biperiden, i.v., adrenergic nerve influence by cervical sympathectomy just prior to the expts. Tubocurarine chloride was used to cause relaxation of striated muscles in the expts with NV stim. We found 100 micrograms (D-Pro2, D-Trp7,9)-SP to cause miosis, breakdown of the BAB with heavy leakage of Evans blue into the ciliary processes and aqueous humor, and a rise in IOP. At 10 micrograms (D-Pro2, D-Trp7,9)-SP caused slight miosis and did not inhibit the miosis caused by SP or capsaicin, but caused a significant reduction of the miotic response caused by PGE1 and NV stim. The rise in protein concentration in the aqueous humor caused by SP or PGE1 was slightly but significantly lower after pretreatment with (D-Pro2, D-Trp7,9)-SP. Thus (D-Pro2, D-Trp7,9)-SP was found to act as a SP agonist on the sphincter pupillae muscle, on the BAB and IOP. However, (D-Pro2, D-Trp7,9)-SP seemed to have some SP antagonistic effects on mechanisms that require sensory nerve conduction e.g. miosis caused by PGE1 and NV stim. The antagonistic mechanism is not clear. The SP analogue may have an unspecific membrane stabilizing effect or a toxic effect or block SP receptors on the sensory nerve fibers. Such effects of (D-Pro2, D-Trp7,9)-SP may explain also why the rise in protein concentration in the aqueous humor caused by SP and PGE1 was lower in eyes pretreated with (D-Pro2, D-Trp7,9)-SP.
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PMID:In the eye (D-Pro2, D-Trp7,9)-SP is a substance P agonist, which modifies the responses to substance P, prostaglandin E1 and antidromic trigeminal nerve stimulation. 619 Mar 53


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