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Query: UNIPROT:P20366 (
substance P
)
21,176
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
In order to study alterations of peripheral
substance P
(SP) and vasoactive intestinal peptide (VIP) in the immunoreactive nervous system in essential hypertension, plasma SP and VIP concentrations in
stroke
-prone spontaneously hypertensive rats (SHRSP) at 8, 12, 18, 28, 30, 35 and 48 weeks of age and age-matched Wistar-Kyoto rats (WKY) were measured, using enzyme immunoassays (EIAs). The mean plasma SP concentrations of SHRSP (n = 61) and WKY (n = 58) were 4.9 +/- 1.2 fmol/ml and 6.6 +/- 1.9 fmol/ml, respectively. The value of SHRSP was significantly lower than that of WKY (p < 0.01). The mean SP concentration of young SHRSP was significantly higher than those of other ages. The mean plasma VIP concentrations of SHRSP (n = 61) and WKY (n = 58) were 0.80 +/- 0.25 fmol/ml and 1.01 +/- 0.32 fmol/ml, respectively. The value of SHRSP was significantly lower than that of WKY (p < 0.01). These decreases in plasma SP and VIP concentrations of SHRSP were observed at all ages. Decreases in the peripheral release of SP and VIP from the endings of SP- and VIP-immunoreactive nerves of SHRSP were seen, and the functional involution of peripheral SP- and VIP-immunoreactive nerves in essential hypertension was suggested.
...
PMID:Decreases in substance P and vasoactive intestinal peptide concentrations in plasma of stroke-prone spontaneously hypertensive rats. 751 29
While hypertension is a major risk factor for
stroke
, it is not its sole determinant. Despite similar blood pressures, spontaneously hypertensive rats (SHR) do not share the predisposition to cerebrovascular disease typical of
stroke
-prone spontaneously hypertensive rats (SHRSP). We investigated vascular function in male SHR and SHRSP as well as in SHRSP/SHR-F2 hybrid animals. Animals were maintained on the appropriate dietary regimen necessary for the manifestation of
stroke
. Among the hybrid animals, a group of
stroke
-prone and a group of
stroke
-resistant rats were selected. Blood pressure was similar in all groups. Endothelium-independent vascular reactivity tested on isolated rings of thoracic aorta and basilar artery after death showed similar contractile and dilatory responses to serotonin and nitroglycerin, respectively, in all groups. In contrast, endothelium-dependent relaxation, in response to acetylcholine or
substance P
, was markedly reduced in SHRSP compared with SHR. Similarly, reduced vasodilatory responses were present in aortae of F2 rats that had suffered a
stroke
when compared with SHR or F2 rats resistant to
stroke
. The observed association and cosegregation of
stroke
with significant and specific impairment of endothelium-dependent vasorelaxation among SHRSP and
stroke
-prone F2 hybrids, respectively, suggest a potential causal role of altered endothelium-dependent vascular relaxation in the pathogenesis of
stroke
.
...
PMID:Association and cosegregation of stroke with impaired endothelium-dependent vasorelaxation in stroke prone, spontaneously hypertensive rats. 875 32
The radioactive microsphere technique was used to determine the contribution of acute changes in systemic hemodynamic variables to the lowering of blood pressure caused by
substance P
in rats anesthetized with urethane. Infusion of 0.74 nmol/kg/min of
substance P
caused a decrease of blood pressure, cardiac output,
stroke
volume and blood flow to most tissues. Total and regional vascular resistances were not affected. Heart rate was increased. These results suggest that the lowering of blood pressure caused by
substance P
occurs as a result of the decreased
stroke
volume and cardiac output. The most likely explanation for the decreased
stroke
volume is a decreased venous return. Several studies have shown that
substance P
has a direct effect to dilate peripheral arteries. Since
substance P
dilates arteries, one would expect a decrease of peripheral vascular resistance. The results of this study suggest, however, that counter-regulatory processes, elicited in response to the vasodilatation and direct effects of
substance P
on sympathetic ganglia to increase the sympathetic nervous system activity, offset the direct effect of
substance P
on arteries that would otherwise cause a decrease of peripheral vascular resistance.
...
PMID:Contribution of hemodynamic variables to the lowering of blood pressure by substance P in the anesthetized rat. 883 48
1. The relaxant of vasodilator peptides were examined in ring preparations of basilar arteries from
stroke
-prone spontaneously hypertensive rats (SHRSP) and Wistar-Kyoto (WKY) rats. 2. Vasoactive intestinal peptide and peptide histidine isoleucine produced similar endothelium-independent relaxations in basilar arteries from WKY rats and SHRSP. Calcitonin gene-related peptide (CGRP) elicited endothelium-independent relaxations in both groups and the CGRP-induced relaxation was greater in SHRSP than in WKY rats.
Substance P
and
neurokinin A
did nor relax basilar arteries from either group. 3. Both WKY rat and SHRSP basilar arteries were relatively insensitive to atrial natriuretic peptide, brain natriuretic peptide and C-type natriuretic peptide. 4. Bradykinin (BK) potently relaxed basilar arteries with endothelium, but BK produced contractions in endothelium-rubbed arteries in both WKY rats and in SHRSP. There was no significant difference in the relaxant response to BK between WKY rat and SHRSP arteries. 5. Adrenomedullin (AM) produced endothelium-independent relaxations in both groups and the relaxant response to AM was significantly greater in SHRSP than in WKY rats. 6. Human CGRP(8-37;mumol/L), a CGRP receptor antagonist, significantly inhibited both relaxant responses induced by CGRP and AM in WKY rats and in SHRSP arteries. 7. Among various peptides tested, the responses to CGRP and AM were higher in basilar arteries from SHRSP than in those from WKY rats. The relaxation produced by AM may be via CGRP receptors in WKY rat and SHRSP basilar arteries.
...
PMID:Relaxant effects of vasodilator peptides on isolated basilar arteries from stroke-prone spontaneously hypertensive rats. 907 89
The role of
substance P
in neural reflex pathways activated by stroking was investigated in muscle-stripped segments of distal colon from guinea pigs. Stroking the mucosal surface with a brush at 1
stroke
/s evoked an increase in short-circuit current (Isc) indicative of chloride secretion. The response to mucosal stroking was maximally reduced by 69-75% by the antagonist GR-82334. The agonist [Sar9,Met(O2)11]
substance P
caused a bumetanide-sensitive increase in Isc when added to the mucosal or serosal bath. Ablation of extrinsic afferents with acute or chronic administration of capsaicin did not alter the mucosal stroking response. Reverse transcription-polymerase chain reaction and in situ hybridization revealed the presence of neurokinin1 (NK1) receptor messenger RNA in isolated colonocytes or crypt glands. Ligand binding of 125I-Bolton-Hunter-labeled
substance P
was inhibited by GR-82334. The 50% inhibitory concentration was 0.84 nM. The results demonstrate a role for
substance P
released from capsaicin-insensitive submucosal neurons and in mucosal stroking reflexes. The presence of NK1 receptors on isolated colonocytes suggests that appropriate elements are present for axon reflex activation of intestinal epithelial cells.
...
PMID:Substance P as a mediator of colonic secretory reflexes. 912 47
BRAIN AND BLOOD PRESSURE IN EXPERIMENTAL ANIMALS: Our experiments in models of experimental hypertension in the rabbit in the early 1970s demonstrated that increased activity of bulbospinal pressor neurons containing noradrenaline or serotonin mediated the elevated arterial blood pressure. Other workers had demonstrated decreased activity of noradrenergic neurons in the medulla. Accordingly, I proposed the hypothesis that the hypertension in these models arose from 'disinhibition', due to unrestrained activity of descending pressor pathways, released from the inhibitory influences present in normal animals. Over the next 15-20 years, experiments from our group and from other laboratories demonstrated that there were two distinct bulbospinal pressor pathways descending from the rostral ventral medulla, one containing adrenaline, neuropeptide Y and glutamate, and the other containing serotonin,
substance P
and glutamate. It has also been established that the key depressor area is in the caudal ventrolateral medulla and that the main inhibitory input, restraining the activity of the bulbospinal pressor pathways, is a short gamma-aminobutyric acid (GABA) projection ascending from the caudal ventrolateral medulla to the rostral ventral medulla. More recent experiments in the spontaneously hypertensive rat (SHR) using the immediate-early gene c-fos as a marker of neuronal activity, have demonstrated that impaired activity of this short inhibitory GABA pathway in the SHR disinhibits the bulbospinal pressor pathway, thus contributing to the hypertension in this model. BLOOD PRESSURE AND
STROKE
IN HUMANS: The risks of primary
stroke
and of secondary or recurrent
stroke
are both directly related to the level of blood pressure and clinical trials have clearly demonstrated that lowering blood pressure markedly reduces the incidence of primary
stroke
. The Perindopril Protection Against Recurrent
Stroke
Study (PROGRESS) was launched to test the hypothesis that lowering the blood pressure in subjects who have already had a
stroke
or a transient ischaemic attack will also reduce the risk of
stroke
. A major unresolved issue for practising clinicians is how to manage the raised blood pressure that is so common in the acute phase of
stroke
. Accordingly, the PROGRESS investigators are planning another major multinational trial to assess the benefits and risks of lowering blood pressure in the first 3 days after the onset of a
stroke
.
...
PMID:Volhard Lecture. Brain, blood pressure and stroke. 988 69
The reactivity of intrarenal arteries to vasoconstrictor and vasodilator polypeptides was examined in adult
stroke
-prone spontaneously hypertensive rats (SHRSP). The contraction response to endothelin-1 (ET-1) was greater in SHRSP than in age-matched Wistar-Kyoto rats (WKY), and so was the pD2 estimate (8.05+/-0.03 in SHRSP, and 7.73+/-0.06 in WKY; n=5, P < 0.05). The contraction response to, and the pD2 estimate of, vasopressin were comparable in SHRSP and WKY. Neuropeptide Y did not contract the intrarenal arteries. In norepinephrine-precontracted arteries with intact endothelium,
substance P
and
neurokinin A
did not relax the arteries of either SHRSP or WKY, while calcitonin gene-related peptide (CGRP) induced a profound relaxation response. Relaxation response to CGRP was significantly greater in SHRSP than in WKY. Atrial, brain, and C-type natriuretic peptides (ANP, BNP, CNP), vasoactive intestinal polypeptide (VIP), and peptide histidine isoleucine (PHI) all caused relaxation responses, with a greater extent of relaxation to ANP, BNP, and VIP and a less extent to CNP and PHI. However, there were no significant differences in these relaxation responses between SHRSP and WKY. The current results revealed the character of heterogeneity of rat intrarenal arteries in response to vasoconstrictor and vasodilator peptides, and showed an enhanced reactivity to ET-1 and to CGRP in SHRSP.
...
PMID:Reactivity of intrarenal arteries to vasoconstrictor and vasorelaxant polypeptides in adult stroke-prone spontaneously hypertensive rats. 1064 9
The cardiovascular actions of python bradykinin (BK) and
substance P
(SP) have been investigated in the anesthetized ball python, Python regius. Bolus intra-arterial injections of python BK (0.03-3 nmol/kg) produced concentration-dependent increases in arterial blood pressure, heart rate (HR), and cardiac output concomitant with small decreases in systemic resistance and
stroke
volume. Intra-arterial injection of 3 nmol/kg python BK produced a tenfold increase in circulating concentration of norepinephrine, but epinephrine levels did not change. BK-induced tachycardia was attenuated (>90%) by the beta-adrenergic receptor antagonist sotalol, and the hypertensive response was attenuated (>70%) by the alpha-adrenergic receptor antagonist prazosin, indicating that effects of python BK are mediated at least in part by activation of the extensive network of adrenergic neurons present in vascular tissues. Bolus intra-arterial injections of python SP in the range 0. 01-30 pmol/kg produced concentration-dependent decreases in arterial blood pressure and systemic peripheral resistance concomitant with increases in cardiac output and
stroke
volume but with only minor effects on HR. The data suggest that kinins play a physiologically important role in cardiovascular regulation in the python.
...
PMID:Cardiovascular actions of python bradykinin and substance P in the anesthetized python, Python regius. 1093 42
To test the hypothesis of an involvement of tachykinins in destabilization and hyperexcitation of neuronal circuits, gliosis, and neuroinflammation during cerebral ischemia, we investigated cell-specific expressional changes of the genes encoding
substance P
(SP), neurokinin B (NKB), and the
tachykinin
/neurokinin receptors (NK1, NK2, and NK3) after middle cerebral artery occlusion (MCAO) in the rat. Our analysis by quantitative in situ hybridization, immunohistochemistry, and confocal microscopy was concentrated on cerebrocortical areas that survive primary infarction but undergo secondary damage. Here, SP-encoding
preprotachykinin
-A and NK1 mRNA levels and SP-like immunoreactivity were transiently increased in GABAergic interneurons at 2 d after MCAO. Coincidently, MCAO caused a marked expression of SP and NK1 in a subpopulation of glutamatergic pyramidal cells, and in some neurons SP and NK1 mRNAs were coinduced. Elevated levels of the NKB-encoding
preprotachykinin
-B mRNA and of NKB-like immunoreactivity at 2 and 7 d after MCAO were confined to GABAergic interneurons. In parallel, the expression of NK3 was markedly downregulated in pyramidal neurons. MCAO caused transient NK1 expression in activated cerebrovenular endothelium within and adjacent to the infarct. NK1 expression was absent from activated astroglia or microglia. The differential ischemia-induced plasticity of the
tachykinin
system in distinct inhibitory and excitatory cerebrocortical circuits suggests that it may be involved in the balance of endogenous neuroprotection and neurotoxicity by enhancing GABAergic inhibitory circuits or by facilitating glutamate-mediated hyperexcitability. The transient induction of NK1 in cerebrovenular endothelium may contribute to ischemia-induced edema and leukocyte diapedesis. Brain
tachykinin
receptors are proposed as potential drug targets in
stroke
.
...
PMID:Adaptive plasticity in tachykinin and tachykinin receptor expression after focal cerebral ischemia is differentially linked to gabaergic and glutamatergic cerebrocortical circuits and cerebrovenular endothelium. 1115 66
Nitric oxide (NO) has effects on contractility, energetics and gene expression of failing myocardium. Initial studies on isolated cardiomyocytes showed NO to reduce systolic shortening but intracoronary infusions of NO-donors or of NO synthase (NOS) inhibitors failed to elicit changes in baseline LV contractility indices such as LVdP/dt(max). Intracoronary infusions of NO-donors or of
substance P
, which releases NO from the coronary endothelium, however demonstrated NO to induce a downward displacement of the left ventricular (LV) diastolic pressure-volume relation, consistent with increased LV diastolic distensibility. In end-stage failing myocardium, the increased oxygen consumption is related to reduced NO production and in isolated cardiomyocytes, NO blunts the norepinephrine-induced expression of the fetal gene programme thereby preserving myocardial calcium homeostasis.In dilated cardiomyopathy, changed endomyocardial NOS gene expression has been reported. Because of lower endomyocardial NOS gene expression in patients with higher functional class and lower LV
stroke
work, increased endomyocardial NOS gene expression seems to be beneficial rather than detrimental for the failing heart. A beneficial effect of increased NOS gene expression could result from NO's ability to increase LV diastolic distensibility, to augment LV preload reserve, to reduce myocardial oxygen consumption and to prevent downregulation of calcium ATPase. Upregulated endomyocardial NOS gene expression has also been reported in athlete's heart and could therefore play a role in physiological LV remodeling. Reduced endomyocardial NO content because of decreased NO or increased superoxide production could lower LV diastolic distensibility and contribute to diastolic heart failure. In many conditions such as aging, hypertension, diabetes or posttransplantation, the increased incidence of diastolic heart failure is indeed paralleled by reduced endothelium-dependent vasodilation.
...
PMID:The role of nitric oxide in the failing heart. 1130 29
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