Nowa wersja platformy, zawierająca wyłącznie zasoby pełnotekstowe, jest już dostępna.
Przejdź na https://bibliotekanauki.pl
Ograniczanie wyników
Czasopisma help
Lata help
Autorzy help
Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 42

Liczba wyników na stronie
first rewind previous Strona / 3 next fast forward last
Wyniki wyszukiwania
Wyszukiwano:
w słowach kluczowych:  substance P
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 3 next fast forward last
EN
Substance P (SP) infused into the third cerebral ventricle blocks spontaneous ovulation in female rats, probably through catecholaminergic neurons. The studies presented in this paper were undertaken to investigate whether SP exerts its suppressing effect on ovulation in 6-hydroxydopamine (6-OHDA) pretreated female rats. After 8-12 days following 6-OHDA pretreatment female rats were infused, on the day of proestrus, with vehicle and all animals were found to ovulate or with a solution containing 5 nmol of SP and 89% of female rats were then found to ovulate. In the group pretreated with vehicle and subsequently infused with SP, ovulation was found to occurr only in 25% of animals. The obtained results indicate that spontaneous ovulation in 6-OHDA-pretreated female rats cannot be blocked by i. c. v. administration of SP, and it may be concluded that SP exerts its suppressing effect through the monoaminergic neurons.
EN
The aim of this study was to examine a morphological picture of guinea pig skin that had been injected with neuropeptides (NPS)2 - substance P (SP) and guinea pig vasoactive intestinal peptide (VIP) - to elucidate their local influence. Routine histological stainings were performed, together with immunohistochemical reactions for T cells and for macrophages. In the deeper layers of the skin, T cell and macrophagic infiltrations were observed. The intensity of these changes was greater 24 hours after injections than that observed at the third hour of the experiment.
EN
The aim of this study was to determine histotopography and age-related changes of immunoreactive substance P (SP-IR) nerve plexus in dog cornea. In this research corneas of three groups of dogs of different age were used: young (2-3 months), adult (1-3 years) and old (8 and more years). Immunohistochemical demonstration of SP was performed on 40 um serial free-floating corneal sections cut parallel to the corneal surface. Results showed that SP-IR nerve plexus of dog cornea was formed by thick (21.9-73 μm diameter), medium (7.3-21.8 μm diameter) and thin (2.19-7.2 um diameter) nerve bundles and varicose or smooth nerve fibers branching into terminals. From limbus SP-IR thick nerve bundles ran radially through superficial and intermediate layers of stroma to the central part of cornea. Thick nerve bundles split into medium ones in central and pericentral parts of cornea. They branched repeatedly forming nerve plexus of stroma. Thin nerve bundles located in subepithelium, superficial and intermediate layers of stroma split from thick and medium bundles. Nerve fibres branched from thin bundles, curved and joined with each other, forming a network of various forms. The highest amount of nerve fibres was observed in corneal epithelium and subepithelium layer. The nerve bundles of young dogs were smaller in diameter than those of adults and old ones. With age the density of nerve fibres and thin bundles decreased in corneal epithelium and subepithelium layer. The density of medium and thick bundles in superficial and intermediate stroma was similar in dogs of all ages. No nerve plexus elements were noticed in stromal deep layer and endothelium in dogs of all ages.
EN
Expression of substance-P in human neurons of trigeminal ganglia has been investigated by immunohistochemistry and morphometry. These neurons constituted 12.8% to 32.6% of the total neuronal population in the trigeminal ganglia. Substance-P positive granulations were concentrated around the nucleus, distributed focally in neuroplasm or dispersed over the neuroplasm. Morphometric analysis has indicated the presence of three populations of SP-positive cells: small, medium-sized and large. The results suggest a functional differentiation on the level of the first neurons of the afferent path of the stomatognatic system. Substance-P is likely to play a role in the transmission not only of nociceptive impulses but also of those involved in the mechano-functional stimulation of system activities.
EN
The aim of the present study was to investigate the effect of peptide NK-1 and NK-2 receptors agonists and antagonists (and their natural ligands, i.e., substance P and neurokinin A) on the oxytocin (OT) secretion from the rat neurohypophysis into the blood. Intracerebroventricular (icv) injection of substance P (SP) or highly selective NK-1 receptor agonist - [(Sar9,Met(O2)11)-Substance P] - significantly stimulated the OT secretion from the rat neurohypophysis into the general circulation. After icv injection of the NK-1 receptor antagonist - [(Tyr6,D-Phe7,D-His9)-Substance P (6-11)] - the blood plasma OT concentration was significantly lower, when compared to vehicle-injected animals. On the other hand, the icv administered neurokinin A (NKA) and the NK-2 receptor agonist - [(ß-Ala8)-Neurokinin A (4-10)] - were essentially inactive in modifying OT secretion. However, such injection of the NK-2 receptor antagonist - [(Tyr5,D-Trp6,8,9,Lys-NH210)-Neurokinin A (4-10)] - was found to diminish the blood plasma hormone concentration, when compared to vehicle-injected animals. The neurohypophysial content of OT was decreased in NKA-treated rats, but neither the NK-2 receptor agonist nor antagonist were able to affect the OT output from the rat posterior pituitary. The hypothalamic levels of OT were not modified by any of the studied peptides. The present data strongly indicate a major role for the tachykinin NK-1 receptor in SP- and/or NKA-dependent regulation of OT secretion from the rat neurohypophysis into the blood.
EN
The presence of choline acetyltransferase (ChAT), vesicular acetylcholine transporter (VAChT), neuropeptide Y (NPY), vasoactive intestinal polypeptide (VIP), somatostatin (SOM), galanin (GAL), substance P (SP) and calcitonin gene-related peptide (CGRP) was studied in neurons and nerve fibers of the porcine otic ganglion. ChAT-positive neurons were very numerous while VAChT-positive nerve cells were moderate in number. The number of neurons containing NPY and VIP was lower and those containing SOM, GAL, SP or CGRP were observed as scarce, or single nerve cells. The above mentioned substances (except SOM) were present in nerve fibers of the ganglion. ChAT- and VAChT-positive nerve fibers were numerous, while the number of nerve terminals containing NPY, VIP and SP was lower. GAL- and CGRP-positive nerve fibers were scarce.
EN
Gorąca A., Traczyk W. Z.: The lack of influence of some neuropeptides present in the posterior pituitary lobe on the frequncy of spontaneous contraction of the sisolated heart auricle. Acta Physiol. Pol. 1940, 4 (6): Investigations have shown the presence of a cardiodepressant factor in the fluid incubating the posterior pituitary lobe “in situ”, which decreased contraction frequency of the isolated heart auricle (Acta Physiol. Pol., 1984, 35: 460-468). The influence on the spontaneuos contraction frequency of the isolated heart auricle of the following synthetic neuropeptides was determined: substance P, leu-enkephalin, met-enke- phalin, angiotensin II, arg-vasopressin, oxytocin, delta sleep-inducing peptide and atrial natriuretic factor. It was found that the investigated neuropeptides had no effect on the contraction frequency of the isolated auricle of the heart right atrium of two-day-old rat in a concentration from 2.1 × 10⁻⁷ to 1 × 10⁻³ mol/1 in the bathing medium and it was concluded that their biological properties differ from the cardiodepressant factor.
EN
Tachykinins (TK) are family of peptides including substance P (SP), substance K (SK) and neuromedin K (NK) that have been found in the nerves of the gastrointestinal tract and proposed to act as neurotransmitters to affect the motor, secretory and circulatory functions of the gut, but little is known about their action on the pancreas. In this study three series of tests were carried out to determine the action of SP, SK and NK on pancreatic secretion in conScious dogs and amylase release from the dispersed rat pancreatic acini and to correlate the alterations in pancreatic secretory and circulatory effects of TK in anesthetized dogs. SP, SK and NK infused i. v. in graded doses (0.12-1.0 µg/kg per h) in conscious dogs stimulated pancreatic protein outputs reaching, respectively, 38% and 23% of the maximal response to CCK (40 pmol/kg per h). HCO₃ outputs were also significantly increased but the highest response did not exceed about 5% of secretin (328 pmol/kg per h) maximum. Cholinergic blockade by atropine abolished the pancreatic responses to tachykinins. When added at various concentrations (10⁻¹¹ -10⁻⁷ M) to the incubation medium of rat dispersed pancreatic acini, SK, SP and NK increased in concentration-dependent manner the release of amylase from the resting pancreatic acini and augmented the enzyme release induced by CCK-8 and by urecholine. In anesthetized dogs infused with a background dose of secretin (82 pmol/kg per h), addition of SP, SK and NK caused an immediate and dose-dependent increase in the pancreatic blood flow, oxygen consumption and pancreatic secretion accompanied by a dose-dependent decrease in arterial blood pressure. This study shows that TK are potent pancreatic circulatory stimulants and moderate secretagogues both in vivo and in vitro, acting, at least in part, via cholinergic pathway.
first rewind previous Strona / 3 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.