AIMTo investigate the influence and the mechanism of SK on the contractility of cultured cardiomyocytes of rats.

METHODSThe primary cultured single myocardial cell was treated with SK and the contraction frequency and size of cardiomyocyte were determined by a computer image analysis system. At the same time the effects of propranolol (a beta receptor antagonist), phentolamine (a alpha receptor antagonist), DSP (a tachykinin receptor antagonist) on the action of SK were investigated.

RESULTSSK increased contractive extend of the cardiomyocyte, in which a dose-response relationship of SK at 1.78 x 10(-8) - 1.78 x 10(-5) mol/L exists. But the frequency of contraction did not change, pretreatment with propranolol, phentolamine had no action on the effect of SK, but DSP markedly attenuated the effects of SK.

CONCLUSIONSK may directly enhance the contractility of single cardiomyocyte, which may be related with the tachykinin receptor.

Animals ; Animals, Newborn ; Benzylamines ; pharmacology ; Cells, Cultured ; Dose-Response Relationship, Drug ; Myocardial Contraction ; drug effects ; Myocytes, Cardiac ; drug effects ; physiology ; Neurokinin A ; pharmacology ; Phentolamine ; pharmacology ; Propranolol ; pharmacology ; Rats ; Rats, Wistar ; Receptors, Tachykinin ; antagonists & inhibitors

ObjectiveTo investigate the expressions of substance P (SP) and neurokinin-1 receptor (NK-1R) in the posterior horn of the L5－S2 spinal cord in the rat model of chronic nonbacterial prostatitis (CNP) at different time points of modeling.

METHODSForty adult male SD rats were randomly divided into four groups of equal number, control, 45 d model, 60 d model, and 90 d model, and proteins were obtained from the prostatic tissue of another 30 rats. The CNP model was made by intraperitoneal injection of 0.5 ml DPT vaccineand intradermal injection of mixed solution of 1 ml prostatein extract and complete adjuvant at a 1∶1 ratio, while the control rats were injected with the same volume of normal saline. At 45, 60, and 90 days after modeling, we measured the paw withdrawal threshold (PWT) of the rats, determined the levels of TNF-α, IL-1β, IL-2, and IL-10 in the prostate tissue by ELISA, observed the histomorphological changes in the prostate by transmission electron and light microscopy, and detected the expressions of SP and NK1-R in the L5－S2 spinal cord by immunohistochemistry.

RESULTSThe model rats showed significantly increased sensitivity to pain, with remarkably lowered PWT at 45, 60, and 90 days after modeling. The levels of TNF-α, IL-1β, IL-2, and IL-10 in the prostate tissue were markedly elevated in the CNP models as compared with those in the controls (all P<0.05), most significantly at 90 days (all P<0.05). Immunohistochemistry showed that the expressions of SP and NK-1R were remarkably higher in the CNP model groups than in the control (all P<0.05), the highest at 90 days. Light microscopy revealed no inflammatory cell infiltration in the prostate tissue of the control rats, and obvious edema and increased lymphocytes were observed with the prolonged time of modeling.Transmission electron microscopy showed inflammatory changes in the prostate tissue of the model rats and that peritubular interstitial edema was most obvious at 90 days, with widened intervals between peritubular cells and the epithelial base and increased numbers of fibroblasts and collagen fibrils.

CONCLUSIONSThe synthesis of SP and the level of NK-1R were increased in the posterior horn of the L5－S2 spinal cord in the rat model of CNP.

Animals ; Interleukin-10 ; metabolism ; Interleukin-1beta ; metabolism ; Interleukin-2 ; metabolism ; Male ; Pain ; Prostatitis ; metabolism ; physiopathology ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Receptors, Neurokinin-1 ; metabolism ; Spinal Cord ; metabolism ; Substance P ; metabolism ; Tumor Necrosis Factor-alpha ; metabolism

BACKGROUND: Asthma is an inflammatory disease because there are many inflammatory changes in the asthmatic airways. Axon reflex mechanisms may be involved in the pathogenesis of asthma. Sensory neuropeptides are involved in this inflammation, which is defined as neurogenic inflammation. Substance p, neurokinin A, and neurokinin B may be main neuropeptides of neurogenic inflammation in airways. These tachykinins act on neurokinin recptors. Three types of neurokinin receptors, such as NK1, NK2, and NK3, are currently recognized, at which substance p,neurokinin A, and neurokinin B may be the most relvant natural agonist of neurogenic inflammation in airways. The receptor subtypes present in several tissues have been characterized on the basis of differential sensitivity to substance p, neurokinin A, and neurokinin B. Plasma extravasation and vasodilation are induced by substance p more potently than by neurokinin A, indicating NK1 receptors on endothelial cells mediate the response. But airway contraction is induced by neurokinin A more potently than by substance P, indicating the NK2 receptors in airway smooth muscles. These receptors are used to evaulate the pathogenesis of brochial asthma. FK224 was identified from the fermentation products of Streptomyces violaceoniger. FK224 is a dual antagonist of both NK1 and NK2 recptors. PURPOSE: For a study of pathogenesis of bronchial asthma, the effect of FK224 on plasma extravasation induced by vagal NANC electrical stimulation was evaluated in rat airway. METHOD: Male Sprague-Dawley rats weighing 180~450gm were anesthetized by i.p. injection of urethane. Plasma extravasation was induced by electrical stimulation of cervical vagus NANC nerves with 5Hz, 1mA, and 5V for 2 minutes(NANC2 group) and for sham operation without nerve stimulation(control group). To evaluate the effect of FK224 on plasma extravasation in neurogenic inflammation, FK224(lmg/kg, Fujisawa Pharmaceutical Co., dissolved in dimethylsul- phoxide; DMSO, Sigma Co.) was injected 1 min before nerve stimulation(FK224 group). To assess plasma exudation, Evans blue dye(20mg/kg,dissolved in saline) was used as a plasma marker and was injected before nerve stimulation. After removal of intravascular dye, the evans blue dye in the tissue was extracted in formamide(37degreesC, 24h) and quantified spectrophotometrically by measuring dye absorbance at 629nm wavelength. Tissue dye content was expressed as ng of dye per mg of wet weight tissue. The amount of plasma extravasation was measured on the part of airways in each groups. RESULTS: 1) Vagus nerve(NANC) stimulation significantly increased plasma leakage in trachea, main bronchus, and peripheral bronchus compared with control group, 14.1 +/-1.6 to 49.7+/-2.5, 17.5 +2.0 to 38.7 +/-2.8, and 12.7+/-2.2 to 19.1 +/-1.6ng of dye per mg of tissue(mean +/- SE), respectively(p< 0.05). But there was not significantly changed in lung parenchyma(p >0.05) 2) FK224 had significant inhibitory effect upon vagal nerve stimulation-induced airway plasma leakage in any airway tissues of rat,such as trachea, main bronchus, and peripheral bronchus compared with vagus nerve stimulation group, 49%, 58%, and 70%, respectively(p<0.05). Inhibitory effect of FK224 on airway plasma leakage in neurogenic inflammation was revealed the more significant in peripheral bronchus, but no significant in lung parenchyma. CONCLUSION: These results suggest that FK224 is a selective NK receptor antagonist which effectively inhibits airway plasma leakage induced by the endogenous neurotransmitters relased by neurogenic inflammation in rat airway. Tachykinin receptor antagonists may be useful in the treatment of brochial asthma.
Animals ; Asthma ; Axons ; Bronchi ; Dimethyl Sulfoxide ; Electric Stimulation ; Endothelial Cells ; Evans Blue ; Fermentation ; Humans ; Inflammation ; Lung ; Male ; Muscle, Smooth ; Neurogenic Inflammation* ; Neurokinin A ; Neurokinin B ; Neuropeptides ; Neurotransmitter Agents ; Plasma* ; Rats* ; Rats, Sprague-Dawley ; Receptors, Tachykinin ; Reflex ; Streptomyces ; Substance P ; Tachykinins ; Trachea ; Urethane ; Vagus Nerve Stimulation ; Vasodilation

OBJECTIVETo investigate the effects of substance P on cultured rat osteoclasts.

METHODSNeurokinin-1 (NK1) receptor expression in osteoclasts was examined by immunohitochemical method, and changes of bone resorption activity caused by substance P and NK1 receptor antagonists were detected by pit formation assay.

RESULTSImmunoreactivity for NK1 receptor was distributed in the cytoplasm of osteoclasts. The average of pit formation areas significantly increased with addition of substance P (10(-7)-10(-4) mol/L) (P < 0.05), but the number of pitformations did not change (P > 0.05). NK1 receptor antagonists inhibited the enhancement of the bone resorption by substance P addition.

CONCLUSIONThe findings suggested that substance P may stimulate osteoclasts and result in bone resorption by the mediation of NK1 receptor.

Animals ; Osteoclasts ; Rats ; Receptors, Neurokinin-1 ; Substance P

OBJECTIVE: In inflammation, hyperalgesia is a common phenomenon but its mechanism has not been clarified. Recently some reports suggested substance P might be important factors for inflammatory hyperalgesia in somatic tissue. This study was performed to see whether substance P modulate the activities of uterine afferent fibers in the hypogastric nerve of the cat. METHODS: While recording the electrical activities of nerve fibers, mechanical stimuli were applied as balloon distention using balloon inserted into uterine lumen before and during substance P infusion through uterine artery. RESULTS: Substance P increased the responses to balloon distension of uterus in 14 uterine mechanoreceptive afferent fibers of 24 over 10% compared to before substance P infusion, and decreased the responses of 3. And L-703,606, the neurokinin 1 receptor antagonist failed the modulation of mechano sensitive response by substance P and reduced the spontaneous activities. CONCLUSIONS: These results suggest that substance P modulated the activities of uterine nerve fibers and their responses to mechanical stimulus. It is hypothesized that this kind of modulation of afferent nerve fibers by substance P may be important for the development of inflammatory hyperalgesia.
Animals ; Cats ; Hyperalgesia ; Inflammation ; Mechanoreceptors* ; Nerve Fibers ; Receptors, Neurokinin-1 ; Substance P* ; Uterine Artery ; Uterus

The pre-Bötzinger complex (pre-BötC) residing in the ventrolateral medulla oblongata, is thought to be the kernel of respiratory rhythmogenesis. Episodic hypoxia exerts respiratory long-term facilitation, being recognized as electrophysiological characteristic of respiratory motor neuroplasticity. Our previous study demonstrated up-regulated expression of phospho-protein kinase C θ (P-PKCθ) in the pre-BötC of rats receiving chronic intermittent hypoxic (CIH) challenge. The present study was aimed to examine subcellular distribution of P-PKC substrates (P-PKCsub) and explore PKC down-stream targeting proteins in the pre-BötC in normoxic and CIH rats. Using neurokinin-1 receptor (NK1R) as a marker of the pre-BötC, P-PKCsub immunoreactivity was revealed by immunofluorescence and immuno-electron microscopic double-labeling in the pre-BötC. Western blot was applied to analyze P-PKCsub proteins in ventrolateral medulla, containing the pre-BötC. The results showed that NK1R immunoreactivity (NK1R-ir) was expressed mainly along plasma membranes of somata and processes, outlining pre-BötC neurons under the light microscope. P-PKCsub immunoreactive (P-PKCsub-ir) fluorophores in dot-like appearance appeared in somata and processes. Some were in close apposition to plasma membranes. A majority of P-PKCsub-ir neurons was found with NK1R-ir. CIH challenge up-regulated the expression of P-PKCsub proteins in the ventrolateral medulla. Under the electron microscope, NK1R-ir product was found to distribute along the inner membrane surfaces of somata and dendrites. P-PKCsub-ir gold particles were located in somata and dendrites, and some were distributed along the inner membrane surfaces, as well as in the endoplasmic reticulum and postsynaptic dense body. These results suggest that CIH challenge up-regulates the expression of P-PKCsub proteins, probably including some receptor proteins in the postsynaptic membrane, which may contribute to respiratory neuroplasticity via activation of PKCθ in the pre-BötC.
Animals ; Hypoxia ; Medulla Oblongata/metabolism* ; Neurons/metabolism* ; Rats ; Rats, Sprague-Dawley ; Receptors, Neurokinin-1/metabolism*

BACKGROUND: 5-HT3 receptor antagonist, dexamethasone and droperidol were used for the prevention of postoperative nausea and vomiting (PONV). Recently, neurokinin-1 (NK1) antagonist has been used for PONV. We evaluated the effect of oral aprepitant premedication in addition to ondansetron. METHODS: A total 90 patients scheduled for elective rhinolaryngological surgery were allocated to three groups (Control, Ap80, Ap125), each of 30 at random. Ondansetron 4 mg was injected intravenously to all patients just before the end of surgery. On the morning of surgery, 80 mg and 125 mg aprepitant were additionally administered into the Ap80 group and Ap125 group, respectively. The rhodes index of nausea, vomiting and retching (RINVR) was checked at 6 hr and 24 hr after surgery. RESULTS: Twelve patients who used steroids unexpectedly were excluded. Finally 78 patients (control : Ap80 : Ap125 = 24 : 28 : 26) were enrolled. Overall PONV occurrence rate of Ap125 group (1/26, 3.9%) was lower (P = 0.015) than the control group (7/24, 29.2%) at 6 hr after surgery. The nausea distress score of Ap125 group (0.04 +/- 0.20) was lower (P = 0.032) than the control group (0.67 +/- 1.24) at 6 hr after surgery. No evident side effect of aprepitant was observed. CONCLUSIONS: Oral aprepitant 125 mg can be used as combination therapy for the prevention of PONV.
Dexamethasone ; Droperidol ; Humans ; Morpholines ; Nausea ; Ondansetron ; Postoperative Nausea and Vomiting ; Premedication ; Receptors, Neurokinin-1 ; Receptors, Serotonin, 5-HT3 ; Steroids ; Vomiting

OBJECTIVE: To find out wheather the substance P takes part in the pain mediating system of uterus, and to ascertain the role of substance P in the hypersensitivity of hypogastric nerve to bradykinin during the uterine inflammation. METHODS: The uterus has two sensory innervations, which are the hypogastric nerve and the pelvic nerve. Since the hypogastric nerve is known to show increased sensitivity to bradykinin, a pain mediator, when the uterus is in inflammatory state, the hypogastric nerve recording was done for electrophysiological study of uterine pain-mediating mechanism in female SD rats (200-250 g). NK1 receptor antagonist (L-703,606) was injected through uterine artery before injecting bradykinin while uterus was under inflammation. RESULTS: The NK-1 receptor antagonist (L-703,606) decreased the spontaneous nerve impulse during inflammation, and it also decreased the hypersensitivity of the hypogastric nerve to bradykinin during the uterine inflammation. CONCLUSION: Substance P mediates the pain sense of hypogastric nerve, and it also plays a role in increased sensitivity of hypogastric nerve to bradykinin while uterus is in inflammatory state.
Action Potentials ; Animals ; Bradykinin* ; Female ; Humans ; Hypersensitivity ; Inflammation ; Mustard Plant* ; Negotiating ; Rats* ; Receptors, Neurokinin-1* ; Substance P ; Uterine Artery ; Uterus*

BACKGROUND AND OBJECTIVES: In airway tissues, the substance P has been suggested as the neurotransmitter in the afferent sensory nerve which responds to various irritants and that it may be involved in airway allergic reactions. Neurokinin 1 receptor exhibits preferential affinity for the substance P. In contrast to the substance P, neurokinin 1 receptor has not been examined at the protein level in nasal mucosa with allergic rhinitis. The purpose of this study was to investigate the localization and distribution of the neurokinin 1 receptor in the nasal mucosa of normal subjects and allergic rhinitis subjects. MATERIALS AND METHOD: Biopsy specimens were collected from 10 normal control subjects and 10 allergic rhinitis subjects and were immunostained for the neurokinin 1 receptor. Expressions of neurokinin 1 receptor were quantified through a light microscope. RESULTS: Neurokinin 1 receptor was localized at the epithelium, inflammatory cells, vascular endothelial cells, and glandular cells in the nasal mucosa of both normal subjects and allergic rhinitis subjects. When comparing the distributions of normal nasal mucosa and neurokinin 1 receptor, the neurokinin 1 receptor was significantly increased in the epithelial cell layer of allergic rhinitis, but there was no difference in the submucosa between two groups. CONCLUSION: These results show that neurokinin 1 receptor in the nasal epithelial cells may play an important role in the pathogenesis of hyper-reactivity in allergic rhinitis.
Biopsy ; Endothelial Cells ; Epithelial Cells ; Epithelium ; Hypersensitivity ; Irritants ; Nasal Mucosa ; Neurotransmitter Agents ; Receptors, Neurokinin-1* ; Rhinitis* ; Substance P

BACKGROUND: To identify a new strategy for postoperative pain management, we investigated the analgesic effects of allopregnanolone (Allo) in an incisional pain model, and also assessed its effects on the activities of the primary afferent fibers at the dorsal horn. METHODS: In experiment 1, 45 rats were assigned to Control, Allo small-dose (0.16 mg/kg), and Allo large-dose (1.6 mg/kg) groups (n = 15 in each). The weight bearing and mechanical withdrawal thresholds of the hind limb were measured before and at 2, 24, 48, and 168 h after Brennan's surgery. In experiment 2, 16 rats were assigned to Control and Allo (0.16 mg/kg) groups (n = 8 in each). The degree of spontaneous pain was measured using the grimace scale after the surgery. Activities of the primary afferent fibers in the spinal cord (L6) were evaluated using immunohistochemical staining. RESULTS: In experiment 1, the withdrawal threshold of the Allo small-dose group was significantly higher than that of the Control group at 2 h after surgery. Intergroup differences in weight bearing were not significant. In experiment 2, intergroup differences in the grimace scale scores were not significant. Substance P release in the Allo (0.16 mg/kg) group was significantly lower than that in the Control group. CONCLUSIONS: Systemic administration of Allo inhibited mechanical allodynia and activities of the primary afferent fibers at the dorsal horn in a rat postoperative pain model. Allo was proposed as a candidate for postoperative pain management.
Animals ; Extremities ; Hyperalgesia ; Pain, Postoperative ; Pregnanolone ; Rats ; Receptors, Neurokinin-1 ; Spinal Cord ; Spinal Cord Dorsal Horn ; Substance P ; Weight-Bearing