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)

Although many peptides have been reported in the vicinity of hypothalamic magnocellular nuclei, their role in the control of neurohypophysial hormone release was only studied for few peptides: opiates, angiotensin II, substance P, CRF, oxytocin and vasopressin. Their effects are briefly recalled and then compared to the more detailed study of their role in the firing pattern of oxytocin and vasopressin neurones. This technique, in some cases, revealed the action site and mechanism of these peptides in the hypothalamo-neurohypophysial system.
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PMID:[Peptidergic control of electrical activities in the magnocellular neurons of the hypothalamus]. 241 39

Administration of 10 micrograms of substance P intrathecally at the spinal T9 level of the unanaesthetized and the anaesthetized rat provoked an increase in arterial pressure and an increase in heart rate. Both cardiovascular responses began within 1-2 min of administration, and the peak of each occurred at 4-10 min. In the anaesthetized rat, which gave rise to the bulk of the responses reported, peak arterial pressure was ca 20 mm Hg greater than pre-administration levels, and peak heart rate was greater by ca 50 beats per min. Similar administration of vehicle failed to alter either parameter. Arterial pressure and heart rate in substance P-treated rats were significantly different from those in vehicle-treated rats up to 15-20 min after administration. Pretreatment with the sympathetic ganglion blocker, hexamethonium (10 mg/kg, i.v.), prevented the responses to intrathecal administration of substance P. Pretreatment with [D-Pro2, D-Phe7, D-Trp9]-substance P, an analogue with antagonist properties in the central nervous system, blocked both responses to substance P but failed to alter similar responses provoked by intrathecal administration of angiotensin II. Pretreatment with vehicle had no effect on responses to substance P or to angiotensin II. The antagonist also had partial agonistic effects. Both arterial pressure and heart rate were transiently increased, but this effect was reversed within 6 min; in the case of heart rate, values returned to the pre-application level but arterial pressure fell to a ca 15 mm Hg below this level. These results demonstrate a pharmacologically specific excitatory effect of substance P on spinal mechanisms controlling sympathetic output to the vessels and the heart; this output can be either via the adrenal medullae or via nerve pathways to the vessels and the heart. Our results also support the possibility that dysfunction of substance P systems at the spinal level may underly some models of hypertension and may be involved in some cases of essential hypertension in man, as well as in autonomic dysfunction associated with some neurological disorders.
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PMID:Substance P given intrathecally at the spinal T9 level increases arterial pressure and heart rate in the rat. 243 74

The isolated, spontaneously active portal vein of guinea pig was stimulated by the following compounds (the pD2 is given in parentheses): caerulein (CER, 8.02), cholecystokinin octapeptide (CCK-8, 7.59), substance P (SP, 4.68), and carbachol (5.37), whereas neurotensin (NT) was ineffective and angiotensin II (AII) produced inhibition. On the portal vein of the rat, CER and CCK-8 were ineffective, whereas stimulation occurred with SP (5.72), NT (6.79), AII (7.89), and carbachol (5.50). Tetrodotoxin did not modify these effects in both types of preparation. Cyclic dibutyryl guanosine monophosphate reduced the effect of CCK-8 and CER but not that of carbachol. It is concluded that the peptides stimulate the portal vein in a way independent from intramural neurons. It may be speculated that receptors for CCK-8 and CER are absent in the portal vein of rat and those for NT in the guinea pig vein.
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PMID:Cholecystokinin octapeptide, caerulein, substance P, neurotensin, and angiotensin II: species-typical effects on the isolated portal vein of guinea pig and rat. 243 99

In a previous study (Watts et al., '87) we reexamined the projections of the suprachiasmatic nucleus (SCh) with the PHA-L method and found that they could be divided conveniently into six groups of fibers. By far the densest projection ends just dorsal to the SCh in a comma-shaped region designated the "subparaventricular zone," although some fibers continue on through the paraventricular nucleus of the hypothalamus to end in the overlying midline thalamus, and others continue on to end in the dorsomedial nucleus, the region around the ventromedial nucleus, and the posterior hypothalamic area. Other relatively sparse projections from the SCh were also described to the preoptic region, lateral septal nucleus, parataenial and paraventricular nuclei of the thalamus, and ventral lateral geniculate nucleus. In addition, the same method was used to show that the subparaventricular zone projects in turn massively to these same regions, as well as back to the SCh itself and to the periaqueductal gray. The present series of experiments was designed to confirm these observations with retrograde tracer injections and to investigate the cellular and possible neurotransmitter organization of the major projections from the SCh and subparaventricular zone with a combined retrograde tracer-immunohistochemical method. For this, the distribution of neuronal cell bodies within the SCh that stain with antisera to vasopressin, vasoactive intestinal polypeptide (VIP), corticotropin-releasing factor, bombesin, substance P, neurotensin, somatostatin, thyrotropin-releasing hormone, and angiotensin II was described in detail first. Then the distribution of retrogradely labeled neurons that were also stained for one or another of these peptides was described after injections of true blue, or in some cases SITS, into the regions of the subparaventricular zone, the paraventricular and parataenial nuclei of the thalamus, the ventromedial nucleus, the dorsomedial nucleus, and the periaqueductal gray. The results confirm previous immunohistochemical and anterograde tracing studies and in addition indicate that cells in dorsal as well as ventral parts of the SCh project to each of the terminal fields examined, as do many cells in surrounding areas, including the subparaventricular zone. Our results also suggest that, at the very least, vasopressin-, VIP-, and neurotensin-stained cells in the SCh project to the subparaventricular zone, midline thalamus, and dorsomedial nucleus, and that the vasopressin and VIP-stained fiber systems are partially segregated at the level of the subparaventricular zone.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Efferent projections of the suprachiasmatic nucleus: II. Studies using retrograde transport of fluorescent dyes and simultaneous peptide immunohistochemistry in the rat. 243 9

Angiotensin I converting enzyme (kininase II; ACE) has been described as a peptidyldipeptidase or dipeptidyl carboxypeptidase (EC 3.4.15.1) of the pulmonary endothelial cells, which liberates angiotensin II or inactivates kinins. However, ACE has a much wider distribution and substrate specifity; it is concentrated in human epithelial cells (e.g. brush border of the kidney, placenta, intestine and choroid plexus), neuroepithelial cells (subfornical organ, pallidonigral dendrites, median eminence) and male genital tract (testes, prostate, epididymides, seminal plasma). Its substrates include enkaphalins, the C-terminal extended proenkephalins and a protected chemotactic tripeptide. Recent, mostly in vitro studies with purified ACE, indicate that ACE also cleaves peptides by other than peptidyldipeptidase action. Homogeneous human ACE inactivated substance P in spite of its blocked C-terminus (Met11-NH2) primarily by releasing the C-terminal tripeptide. A blocked C-terminal tripeptide, Arg-Pro-Gly-NH2 was also released from the luteinizing hormone releasing hormone (LHRH). Although ACE shares many properties with carboxypeptidases, it surprisingly cleaves the N-terminal tripeptide greater than Glu1-His2-Trp3 from LHRH. Because human ACE hydrolyzes a variety of peptide hormones, actions of its inhibitors may go well beyond blocking the conversion of angiotensin I.
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PMID:The broad substrate specificity of human angiotensin I converting enzyme. 244 Jun 24

Specific angiotensin II (ANG II) binding sites in the dorsal aspects of the medulla oblongata of dogs and rats were shown previously to be dependent upon intact sensory and motor components of the vagus nerve. The present studies compared the distribution of ANG II binding sites in the canine medulla with the visualization of substance P immunoreactive fibres, since this peptide is known to be present in vagal afferent fibres. Dense bands of substance P-containing fibres were found to cap the tractus solitarius (TS) in the dorsal subdivision of the nucleus tractus solitarii (nTS) at a level corresponding to the region of highest ANG II binding. In addition, moderate densities of both substance P immunoreactivity and ANG II binding sites were dually localized in the medial nTS and the ventral portion of the dorsal motor nucleus of the vagus (dmnX). Since previous studies indicated that ANG II binding sites are associated with vagal afferent fibres in the nTS and efferent motor neurons in the dmnX, their apparent association with substance P immunoreactive fibres suggests that a functional interaction may occur between these two peptides in the central integration of cardiovascular function.
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PMID:Correlation between angiotensin II binding sites and substance P in the canine brain stem. 244 Oct 17

Adrenergic and osmoregulatory responses to substance P (SP) were studied in salt-loaded ducks. SP inhibited nasal salt secretion by decreasing the salt concentration of the nasal fluid, but reversed the inhibitory effect of angiotensin II (ANG II) on nasal water and K secretion. SP also stimulated salivation, urinary water excretion, and urinary salt excretion, but diminished the diuretic and saluretic responses to ANG II. The osmoregulatory effects of SP were accompanied by elevated plasma concentrations of norepinephrine and epinephrine. The data suggest that SP may contribute to adrenergic and osmotic regulation in ducks.
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PMID:Reevaluation of the effect of substance P on nasal salt gland secretion in the duck (Anas platyrhynchos). 244 66

The microcirculatory effects of vasoactive peptides on arteriolar diameter were determined in the dorsal skin-fold preparation of conscious Syrian hamsters and related to arterial blood pressure (MABP). (5 Ile)-angiotensin II (ANG II), (8 Arg)-vasopressin (AVP), vasoactive intestinal polypeptide (VIP), atrial natriuretic factor (ANF), and substance P (SP) were administered intravenously as bolus injections in picomolar concentrations. The diameters of subcutaneous A3 arterioles (15-40 microns) at bifurcation sites were determined via a microscope video system and stored in a digital memory. When spontaneous rhythmic vasoconstrictions and dilations (vasomotion) were present, the diameter oscillations were analyzed by means of the Prony Spectral Line Estimator. ANG II caused sustained arteriolar contraction at increased MABP, but did neither induce nor modulate vasomotion. Both ANF and VIP slightly reduced MABP and had no effect on microcirculatory parameters. SP led to a significant dilation of subcutaneous arterioles in the hamster skin with concomitant drop in MABP, but did not influence arteriolar vasomotion. Physiological concentrations of AVP, as determined in the plasma by radioimmunoassay, caused a marked contraction of the arterioles and evoked a mild pressor response. In addition, AVP induced or greatly enhanced vasomotoric activity. This study therefore provides evidence that endogenous vasoactive peptides play an important role in regulation of skin peripheral resistance by altering arteriolar diameter in a tonic or even dynamic way.
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PMID:Regulatory role of vasoactive peptides in subcutaneous skin microcirculation of the hamster. 245 Aug 51

The present study examines the effects of intrathecal administration of selected peptides on nociceptive responses in the rat. Each peptide was delivered via a chronically implanted catheter to the L5 vertebral level. In the tail flick test, VIP (0.65-6.5 nmoles) produced a dose-dependent decrease in reaction time (RT) from 1 to 6-16 min after injection; 6.5 nmoles decreased RT to 37% of control value at 1 min after injection. Galanin (0.65-6.5 nmoles) produced a dose-dependent increase in reaction time at 1 and 6 min; at high doses, many of the rats failed to flick the tail. CGRP (6.5 nmoles) produced a small, transient decrease in RT to 73% of control values at 1 min; 3.25 nmoles were without effect. CSF and 6.5 nmoles of somatostatin, TRH and angiotensin II were without effect. At high doses of galanin and CGRP, rats vocalized to innocuous touch of the tail, as reported for substance P. Von Frey hairs were thus applied to the tail after 6.5 nmoles of VIP, galanin, CGRP or substance P. Vocalization in response to a previously innocuous pressure stimulus was observed at 30 s after injection in all rats given galanin and some rats given CGRP or substance P; the effect lasted 4-8 min. VIP and CSF had no effect. These results suggest that VIP, galanin, CGRP and substance P may act as excitatory agents in nociceptive pathways and that specific peptides may function in the different types of pain modalities; VIP in thermal, galanin in mechanical and substance P and CGRP in both.
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PMID:Effects of intrathecal administration of neuropeptides on a spinal nociceptive reflex in the rat: VIP, galanin, CGRP, TRH, somatostatin and angiotensin II. 245 92

Ovarian follicular fluid (FF) of a number of species contain regulatory peptides secreted by granulosa cells or by autonomic nerve terminals. In this report we demonstrate the presence of authentic (HPLC-verification) angiotensin II and III as well as of substance P (SP) in human FF obtained from hMG stimulated infertile patients undergoing in vitro fertilization. Angiotensin II/III (AII/III), estradiol (E2) and progesterone concentrations increase with the size of the follicles. SP concentrations did not vary significantly in FF of various sizes. These peptide concentrations in FF are about 10-fold higher than those measured in the serum of the same patients. Attempts to correlate SP, AII/III, E2 and progesterone concentrations in the individual FF with the ability of an oocyte to be fertilized, failed. Neither AII/III, SP, E2 nor progesterone concentrations were different in these subclasses of FF. Follicles of patients punctured under general anesthesia contained significantly more SP than follicles of patients which had lumbar analgesia. AII/III concentrations were the same in FF of both treatment groups. The presence of angiotensin II and III in FF in increasing concentrations depending on the maturity of the follicle and the inability of general anesthesia to affect the AII/III concentrations suggests that this peptide is produced within the ovary.
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PMID:Angiotensin II/III and substance P in human follicular fluid obtained during IVF: relation of the peptide content with follicular size. 245 91


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