ABSTRACT
@#Objective To analyze the protective mechanism of spinal cord ischemia-reperfusion injury mediated by N-methyl-D-aspartate (NMDA) receptor. Methods A total of 42 SD rats were randomly assigned to 4 groups: a non-blocking group (n=6), a saline group (n=12), a NMDA receptor blocker K-1024 (25 mg/kg) group (n=12) and a voltage-gated Ca2+ channel blocker nimodipine (0.5 mg/kg) group (n=12). The medications were injected intraperitoneally 30 min before ischemia. The neural function was evaluated. The neuronal histologic change of spinal cord lumbar region, the release of neurotransmitter amino acids and expression of spinal cord neuronal nitric oxide synthase (nNOS) were compared. Results At 8 h after reperfusion, the behavioral score of the K-1024 group was 2.00±0.00 points, which was statistically different from those of the saline group (5.83±0.41 points) and the nimodipine group (5.00±1.00 points, P<0.05). Compared with the saline group and nimodipine group, K-1024 group had more normal motor neurons (P<0.05). There was no significant difference in glutamic acid concentration in each group at 10 min after ischemia (P=0.731). The nNOS protein expression in the K-1024 group was significantly down-regulated compared with the saline group (P<0.01). After 8 h of reperfusion, the expression of nNOS protein in the K-1024 group was significantly up-regulated compared with the saline group (P<0.05). Conclusion K-1024 plays a protective role in spinal cord ischemia by inhibiting NMDA receptor and down-regulating nNOS protein expression; during the reperfusion, K-1024 has a satisfactory protective effect on spinal cord function, structure and biological activity of nerve cells.
ABSTRACT
This study investigated the effects of different frequencies of repetitive transcranial magnetic stimulation (rTMS) on chronic neuropathic pain in rats.The behavior of rats with experimental chronic neuropathic pain was observed,and the expression of neuronal nitric oxide synthase (nNOS) in the ipsilateral dorsal root ganglions (DRGs) and the activation and proliferation of astrocytes in the ipsilateral spinal dorsal horn were detected.Thirty-two male Sprague-Dawley rats were randomly divided into four groups:sham-operated group,sham-rTMS group,1 Hz group and 20 Hz group (8 rats in each group).Chronic constriction nerve injury induced by sciatic nerve ligation was made to establish the models of the chronic neuropathic pain in rats except those in the sham-operated group.Then we applied different frequencies of rTMS to the primary motor cortex (M1) contralateral to the pain side once daily for 10 consecutive days.Pain behavior scores were observed before and after treatment.Western blot analysis was used to detect the expression of nNOS in ipsilateral L4-6 DRGs.Double immunofluorescent labeling for glial fibrillary acidic protein (GFAP) and 5-bromo-2-deoxyuridine (BrdU) was employed to observe the activation and proliferation of astrocytes in the ipsilateral L4-6 spinal dorsal horn.After rTMS treatment,the spontaneous pain behavior scores were significantly lower in the 20 Hz group than those in the sham-rTMS group (P＜0.05).Moreover,the brush-evoked pain behavior scores were significantly lower in the 20 Hz group than those in the sham-rTMS and 1 Hz group (P＜0.05),suggesting that the spontaneous pain and brush-evoked pain in the 20 Hz group were significantly alleviated.Western blot analysis revealed that the expression of nNOS in ipsilateral L4-6 DRGs was significantly decreased in the 20 Hz group as compared with the sham-rTMS group and the 1 Hz group (P＜0.01) after rTMS treatment.Double immunofluorescence suggested that the expression of GFAP and the co-localization with BrdU in astrocytes were less in the sham-operated group than those in the sham-rTMS group and the 1 Hz group in L4-6 spinal dorsal horn ipsilateral to the neuropathic pain.After rTMS treatment,the expression of GFAP and the co-localization with BrdU decreased in the 20 Hz group as compared with the sham-rTMS group and the 1 Hz group (P＜0.05).In addition,the alleviation degree of spontaneous pain and brush-evoked pain in the 20 Hz group was negatively correlated with the expression of nNOS in ipsilateral DRGs and the number of GFAP/BrdU co-labelled astrocytes in L4-6 spinal dorsal horn ipsilateral to the neuropathic pain (P＜0.05).It was suggested that high-frequency rTMS may relieve neuropathic pain through down-regulating the overexpression of nNOS in ipsilateral DRGs and inhibiting the activity and proliferation of astrocytes in L4-6 spinal dorsal horn ipsilateral to the neuropathic pain.
ABSTRACT
This study investigated the effects of different frequencies of repetitive transcranial magnetic stimulation (rTMS) on chronic neuropathic pain in rats.The behavior of rats with experimental chronic neuropathic pain was observed,and the expression of neuronal nitric oxide synthase (nNOS) in the ipsilateral dorsal root ganglions (DRGs) and the activation and proliferation of astrocytes in the ipsilateral spinal dorsal horn were detected.Thirty-two male Sprague-Dawley rats were randomly divided into four groups:sham-operated group,sham-rTMS group,1 Hz group and 20 Hz group (8 rats in each group).Chronic constriction nerve injury induced by sciatic nerve ligation was made to establish the models of the chronic neuropathic pain in rats except those in the sham-operated group.Then we applied different frequencies of rTMS to the primary motor cortex (M1) contralateral to the pain side once daily for 10 consecutive days.Pain behavior scores were observed before and after treatment.Western blot analysis was used to detect the expression of nNOS in ipsilateral L4-6 DRGs.Double immunofluorescent labeling for glial fibrillary acidic protein (GFAP) and 5-bromo-2-deoxyuridine (BrdU) was employed to observe the activation and proliferation of astrocytes in the ipsilateral L4-6 spinal dorsal horn.After rTMS treatment,the spontaneous pain behavior scores were significantly lower in the 20 Hz group than those in the sham-rTMS group (P＜0.05).Moreover,the brush-evoked pain behavior scores were significantly lower in the 20 Hz group than those in the sham-rTMS and 1 Hz group (P＜0.05),suggesting that the spontaneous pain and brush-evoked pain in the 20 Hz group were significantly alleviated.Western blot analysis revealed that the expression of nNOS in ipsilateral L4-6 DRGs was significantly decreased in the 20 Hz group as compared with the sham-rTMS group and the 1 Hz group (P＜0.01) after rTMS treatment.Double immunofluorescence suggested that the expression of GFAP and the co-localization with BrdU in astrocytes were less in the sham-operated group than those in the sham-rTMS group and the 1 Hz group in L4-6 spinal dorsal horn ipsilateral to the neuropathic pain.After rTMS treatment,the expression of GFAP and the co-localization with BrdU decreased in the 20 Hz group as compared with the sham-rTMS group and the 1 Hz group (P＜0.05).In addition,the alleviation degree of spontaneous pain and brush-evoked pain in the 20 Hz group was negatively correlated with the expression of nNOS in ipsilateral DRGs and the number of GFAP/BrdU co-labelled astrocytes in L4-6 spinal dorsal horn ipsilateral to the neuropathic pain (P＜0.05).It was suggested that high-frequency rTMS may relieve neuropathic pain through down-regulating the overexpression of nNOS in ipsilateral DRGs and inhibiting the activity and proliferation of astrocytes in L4-6 spinal dorsal horn ipsilateral to the neuropathic pain.
ABSTRACT
The ganglion cardiacum or juxtaductal body is situated along the left recurrent laryngeal nerve in the aortic window and is an extremely large component of the cardiac nerve plexus. This study was performed to describe the morphologies of the ganglion cardiacum or juxtaductal body in human fetuses and to compare characteristics with intracardiac ganglion. Ganglia were immunostained in specimens from five fetuses of gestational age 12–16 weeks and seven fetuses of gestational age 28–34 weeks. Many ganglion cells in the ganglia were positive for tyrosine hydroxylase (TH; sympathetic nerve marker) and chromogranin A, while a few neurons were positive for neuronal nitric oxide synthase (NOS; parasympathetic nerve marker) or calretinin. Another ganglion at the base of the ascending aorta carried almost the same neuronal populations, whereas a ganglion along the left common cardinal vein contained neurons positive for chromogranin A and NOS but no or few TH-positive neurons, suggesting a site-dependent difference in composite neurons. Mixtures of sympathetic and parasympathetic neurons within a single ganglion are consistent with the morphology of the cranial base and pelvic ganglia. Most of the intracardiac neurons are likely to have a non-adrenergic non-cholinergic phenotype, whereas fewer neurons have a dual cholinergic/noradrenergic phenotype. However, there was no evidence showing that chromogranin A- and/or calretinin-positive cardiac neurons corresponded to these specific phenotypes. The present study suggested that the ganglion cardiacum was composed of a mixture of sympathetic and parasympathetic neurons, which were characterized the site-dependent differences in and near the heart.
Subject(s)
Humans , Aorta , Calbindin 2 , Chromogranin A , Fetus , Ganglia , Ganglion Cysts , Gestational Age , Heart , Neurons , Nitric Oxide Synthase Type I , Phenotype , Recurrent Laryngeal Nerve , Skull Base , Tyrosine 3-Monooxygenase , VeinsABSTRACT
Objective To investigate the therapeutic effect of cell penetrating peptide Tat-LK15 mediating small interfering RNA (siRNA) interference with the expression of neuronal nitric oxide synthase (nNOS) in rat spinal dorsal horn on neuropathic pain. Methods The transfection reagent, Tat-LK15, was used to mediate the transfection of rat spinal dorsal horn (SDH) neuronal cells with carboxyfluorescein (FAM), and then the transfection effect was observed under inverted fluorescence microscope. Fifty healthy male SD rats were randomly divided into 5 groups (n=10): control group, sham operation group (sham group), neuropathic pain group (SNL group), Tat-LK15-nNOS siRNA group (TS group) and Tat-LK15-NC siRNA group (TN group). Neuropathic pain was induced by spinal nerve ligation (SNL), rats in control group did not receive operation and only the spinal nerve was exposed in sham group. Groups SNL, TS and TN were made into the models by SNL and implanted intrathecal catheter, intrathecal administration was performed from the 7th day after model establishment, and 10μl normal saline, 10μl TS complex (including 5μg siRNA) and 10μl TN (including 5μg siRNA) were injected intrathecally each day for 7 days. Paw withdrawal mechanical threshold (PWMT) and paw withdrawal thermal latency (PWTL) were measured at 1 day before (baseline) and 3, 7, 10 and 14 days after model establishment. Then animals were sacrificed on the 14th day after the operation and the lumbar segment (L4-6) of the spinal cord was removed to detect the expressions of nNOS mRNA and protein using q-PCR and Western blotting analysis. Results Tat-LK15 effectively mediated FAM-siRNA into SDH neuronal cells. Compared with sham group, SNL significantly decreased PWMT and PWTL and increased expressions of nNOS mRNA and protein from the 3rd day (P<0.01), but there was no significant difference between the sham and control group. Tat-LK15-nNOS siRNA complex significantly increased PWMT and PWTL and down-regulated nNOS mRNA and protein expressions in TS group compared with SNL group on the days 10 and 14. There was no significant difference between TN and SNL group. Conclusion Tat-LK15 not only can mediate successful nNOS siRNA transfection and inhibit the expression of nNOS, but also effectively relieve SNL-induced neuropathic pain in rats.
ABSTRACT
The frontal nerve is characterized by its great content of sympathetic nerve fibers in contrast to cutaneous branches of the maxillary and mandibular nerves. However, we needed to add information about composite fibers of cutaneous branches of the nasociliary nerve. Using cadaveric specimens from 20 donated cadavers (mean age, 85), we performed immunohistochemistry of tyrosine hydroxylase (TH), neuronal nitric oxide synthase (nNOS), and vasoactive intestinal polypeptide (VIP). The nasocilliary nerve contained abundant nNOS-positive fibers in contrast to few TH- and VIP-positive fibers. The short ciliary nerves also contained nNOS-positive fibers, but TH-positive fibers were more numerous than nNOS-positive ones. Parasympathetic innervation to the sweat gland is well known, but the original nerve course seemed not to be demonstrated yet. The present study may be the first report on a skin nerve containing abundant nNOS-positive fibers. The unique parasympathetic contents in the nasocilliary nerve seemed to supply the forehead sweat glands as well as glands in the eyelid and nasal epithelium.
Subject(s)
Humans , Cadaver , Eyelids , Forehead , Immunohistochemistry , Mandibular Nerve , Nasal Mucosa , Nerve Fibers , Nitric Oxide Synthase Type I , Skin , Sweat Glands , Tyrosine 3-Monooxygenase , Vasoactive Intestinal PeptideABSTRACT
Although the pelvic autonomic plexus may be considered a mixture of sympathetic and parasympathetic nerves, little information on its composite fibers is available. Using 10 donated elderly cadavers, we investigated in detail the topohistology of nerve fibers in the posterior part of the periprostatic region in males and the infero-anterior part of the paracolpium in females. Neuronal nitric oxide synthase (nNOS) and vasoactive intestinal polypeptide (VIP) were used as parasympathetic nerve markers, and tyrosine hydroxylase (TH) was used as a marker of sympathetic nerves. In the region examined, nNOS-positive nerves (containing nNOS-positive fibers) were consistently predominant numerically. All fibers positive for these markers appeared to be thin, unmyelinated fibers. Accordingly, the pelvic plexus branches were classified into 5 types: triple-positive mixed nerves (nNOS+, VIP+, TH+, thick myelinated fibers + or -); double-positive mixed nerves (nNOS+, VIP-, TH+, thick myelinated fibers + or -); nerves in arterial walls (nNOS-, VIP+, TH+, thick myelinated fibers-); non-parasympathetic nerves (nNOS-, VIP-, TH+, thick myelinated fibers + or -); (although rare) pure sensory nerve candidates (nNOS-, VIP-, TH-, thick myelinated fibers+). Triple-positive nerves were 5-6 times more numerous in the paracolpium than in the periprostatic region. Usually, the parasympathetic nerve fibers did not occupy a specific site in a nerve, and were intermingled with sympathetic fibers. This morphology might be the result of an "incidentally" adopted nerve fiber route, rather than a target-specific pathway.
Subject(s)
Aged , Female , Humans , Male , Adrenergic Fibers , Cadaver , Hypogastric Plexus , Myelin Sheath , Nerve Fibers , Nitric Oxide Synthase Type I , Tyrosine 3-Monooxygenase , Vasoactive Intestinal PeptideABSTRACT
Objective In order to explore the mechanism of repetitive transcranial magnetic stimulation rTMS) on neuropathic pain,we observed the effect of different frequencies of rTMS on neuropathic pain and the expression of neuronal nitric oxide synthase (nNOS) in the dorsal root ganglion (DRG).Methods A total of 28 male Sprague-Dawley rats were used and divided into a control group,in which sham-operation was performed,and an experimental group which was further divided into a sham-rTMS group,a 1 Hz group and a 20 Hz group after successful neuropathic pain model was established by operation to ligate the left sciatic nerves,with 7 rats in each group.Three days after the operation,rTMS was applied to the primary motor cortex (M1) contralateral to the pain once dai ly for 10 consecutive days.The pain behavior and nNOS expression in the DRG were measured before and after 10 days of rTMS intervention.Results All the neuropathic pain model rats demonstrated pain-related behaviors 3 days postoperation,the mechanical pain thresholds were significantly lower than those in the control group (P ＜ 0.05).After rTMS treatment,the mechanical hyperalgsia was significantly relieved in 20 Hz group but not 1 Hz group as demonstrated by a comparison with the sham-rTMS group (P ＜ 0.05).The expression of nNOS in DRG ipsilateral to the neuropathic pain was significantly increased in sham-rTMS group and 1 Hz group (P ＜ 0.05) when compared with the control group.Meanwhile,it was shown that expression of nNOS was down-regulated in 20 Hz group but not 1 Hz group (P ＜ 0.05).The degree of pain relief in 20 Hz group was negatively correlated with the expression of nNOS in DRG (P ＜0.05).Conclusions Neuropathic pain induced by peripheral nerve injury is associated with elevated expression of nNOS in the DRG.High-frequency rTMS can relieve neuropathic pain through down-regulating the overexpression of nNOS in the DRG,but the low-frequency rTMS has no such effect.
ABSTRACT
Gene expression of neuronal nitric oxide synthase (nNOS) changes in the hypothalamic paraventricular nucleus (PVN) depending on feeding conditions, which is decreased during food deprivation and restored by refeeding, and phosphorylated cAMP response element binding protein (pCREB) was suggested to play a role in its regulation. This study was conducted to examine if the fasting-induced down-regulation of the PVN-nNOS expression is restored by activation of cAMP-dependent protein kinase A (cAMP/PKA) pathway. Freely moving rats received intracerebroventricular (icv) injection of cAMP/PKA activator Sp-cAMP (40 nmol) or vehicle (sterilized saline) following 48 h of food deprivation. One hour after drug injections, rats were transcardially perfused with 4% paraformaldehyde, and the PVN tissues were processed for nNOS or pCREB immunohistochemistry. Sp-cAMP significantly increased not only nNOS but also pCREB immunoreactivities in the PVN of food deprived rats. Fasting-induced down-regulation of the PVN-nNOS was restored by 1 h after the icv Sp-cAMP. Results suggest that cAMP/PKA pathway may mediate the regulation of the PVN-nNOS expression depending on different feeding conditions.
Subject(s)
Animals , Rats , Cyclic AMP Response Element-Binding Protein , Cyclic AMP-Dependent Protein Kinases , Down-Regulation , Food Deprivation , Formaldehyde , Gene Expression , Immunohistochemistry , Nitric Oxide Synthase Type I , Paraventricular Hypothalamic Nucleus , PolymersABSTRACT
Nitric oxide (NO) modulates the activities of various channels and receptors to participate in the regulation of neuronal intracellular Ca2+ levels. Ca2+ binding protein (CaBP) expression may also be altered by NO. Accordingly, we examined expression changes in calbindin-D28k, calretinin, and parvalbumin in the cerebral cortex and hippocampal region of neuronal NO synthase knockout(-/-) (nNOS-/-) mice using immunohistochemistry. For the first time, we demonstrate that the expression of CaBPs is specifically altered in the cerebral cortex and hippocampal region of nNOS-/- mice and that their expression changed according to neuronal type. As changes in CaBP expression can influence temporal and spatial intracellular Ca2+ levels, it appears that NO may be involved in various functions, such as modulating neuronal Ca2+ homeostasis, regulating synaptic transmission, and neuroprotection, by influencing the expression of CaBPs. Therefore, these results suggest another mechanism by which NO participates in the regulation of neuronal Ca2+ homeostasis. However, the exact mechanisms of this regulation and its functional significance require further investigation.
Subject(s)
Animals , Mice , Calcium , S100 Calcium Binding Protein G , Calcium-Binding Proteins , Carrier Proteins , Cerebral Cortex , Homeostasis , Immunohistochemistry , Neurons , Nitric Oxide , Nitric Oxide Synthase , Synaptic TransmissionABSTRACT
Background Researches demonstrated that epigallocatechin-3-gallate(EGCG) can protect retinal ganglion cells(RGCs) against damage induced by retinal ischemia-reperfusion and optic nerve crush(ONC),but the effect of EGCG on lateral geniculate nucleus(LGN) was under study.Objective This study was designed to detect neuroprotective effect of EGCG on LGN in the rat model with ONC.Methods Forty-eight 7-week-old female clean Wistar rats were randomly divided into normal control group,sham operation+EGCG group,ONC+normal saline(NS) group and ONC+EGCG group.ONC models were created by clamping the optical nerve for 60 seconds with the clipper with the force of 40 grams in the right eyes of 24 rats.The EGCG solution(25mg/kg) was intraperitoneally injected from 2 days before operation daily for 5 consecutively days and orally administered(2mg/kg) after that,and NS was used in the same way for ONC+NS group.Four weeks after ONC,the brain tissue of the rats was obtained,and the neurons of dorsal LGN(dLGN) were counted by Nissl staining under the light microscopy.The expression of neurofilament triplet L(NF-L) was detected by immunohistochemistry and Western blot analysis.Meanwhile,the neuronal nitric oxide synthase(nNOS) positive cells were counted.Results Compared with normal control group,no significant differences were found in neuron number both between sham operation+EGCG group or ipsilateral LGN of operative eyes in ONC+normal saline group and ONC+EGCG group(P=0.906,0.561,0.794,0.646 respectively) in 4 weeks after ONC,but loss of neurons in contralateral LGN in both ONC+normal saline group and ONC+EGCG group were observed(P=0.000,0.015 respectively).However,compared with ONC+normal saline group,the density of neurons in ONC+EGCG group was higher(P=0.007).Moreover,a higher expression level of NF-L protein was seen in ONC+EGCG group compared with ONC+normal saline group at contralateral LGN of operative eyes(P=0.002).Concerning the number of nNOS positive cells in LGN,there was no significant difference among normal control group,sham operation+EGCG group and ONC+EGCG group(P＞0.05).The number of nNOS positive cells in the contralateral LGN of operative eyes of ONC+normal saline group was higher than that of ONC+EGCG group(P=0.000).Conclusion EGCG plays the protective effect on LGN after ONC in rats through mediating the expression of nNOS.
ABSTRACT
Glutamate N-methyl-D-aspartate (NMDA) receptor activation within the dorsal column of the periaqueductal gray (dPAG) leads to antinociceptive, autonomic, and behavioral responses characterized as the fear reaction. Activation of NMDA receptors in the brain increases nitric oxide (NO) synthesis, and NO has been proposed to be a mediator of the aversive action of glutamate. This paper reviews a series of studies investigating the effects of neuronal NO synthase (nNOS) inhibition in the dPAG of mice in different aversive conditions. nNOS inhibition by infusion of Nω-propyl-L-arginine (NPLA) prevents fear-like reactions (e.g., jumping, running, freezing) induced by NMDA receptor stimulation within the dPAG and produces anti-aversive effects when injected into the same midbrain site in mice confronted with a predator. Interestingly, nNOS inhibition within the dPAG does not change anxiety-like behavior in mice exposed to the elevated plus maze (EPM), but it reverses the effect of an anxiogenic dose of NMDA injected into the same site in animals subjected to the EPM. Altogether, the results support a role for glutamate NMDA receptors and NO in the dPAG in the regulation of defensive behaviors in mice. However, dPAG nitrergic modulation of anxiety-like behavior appears to depend on the magnitude of the aversive stimulus.
Subject(s)
Animals , Rats , Behavior, Animal , Periaqueductal Gray , Receptors, N-Methyl-D-AspartateABSTRACT
Nerve injury leads to a neuropathic pain state that results from central sensitization. This phenomenom is mediated by NMDA receptors and may involve the production of nitric oxide (NO). In this study, we investigated the expression of the neuronal isoform of NO synthase (nNOS) in the spinal cord of 3-month-old male, Wistar rats after sciatic nerve transection (SNT). Our attention was focused on the dorsal part of L3-L5 segments receiving sensory inputs from the sciatic nerve. SNT resulted in the development of neuropathic pain symptoms confirmed by evaluating mechanical hyperalgesia (Randall and Selitto test) and allodynia (von Frey hair test). Control animals did not present any alteration (sham-animals). The selective inhibitor of nNOS, 7-nitroindazole (0.2 and 2 µg in 50 µL), blocked hyperalgesia and allodynia induced by SNT. Immunohistochemical analysis showed that nNOS was increased (48 percent by day 30) in the lumbar spinal cord after SNT. This increase was observed near the central canal (Rexeds lamina X) and also in lamina I-IV of the dorsal horn. Real-time PCR results indicated an increase of nNOS mRNA detected from 1 to 30 days after SNT, with the highest increase observed 1 day after injury (1469 percent). Immunoblotting confirmed the increase of nNOS in the spinal cord between 1 and 15 days post-lesion (20 percent), reaching the greatest increase (60 percent) 30 days after surgery. The present findings demonstrate an increase of nNOS after peripheral nerve injury that may contribute to the increase of NO production observed after peripheral neuropathy.
Subject(s)
Animals , Male , Rats , Nitric Oxide Synthase Type I/metabolism , Sciatic Nerve/injuries , Sciatica/enzymology , Gene Expression Regulation, Enzymologic/physiology , Hyperalgesia/enzymology , Hyperalgesia/physiopathology , Immunohistochemistry , Nitric Oxide Synthase Type I/physiology , RNA, Messenger/metabolism , Rats, Wistar , Sciatica/physiopathologyABSTRACT
Nitric Oxide (NO) actively participates in the regulation of neuronal intracellular Ca2+ levels by modulating the activity of various channels and receptors. To test the possibility that modulation of Ca2+ buffer protein expression level by NO participates in this regulatory effect, we examined expression of calbindin-D28k, calretinin, and parvalbumin in the cerebellum of neuronal NO synthase knock-out (nNOS(-/-)) mice using immunohistochemistry. We observed that in the cerebellar cortex of the nNOS(-/-) mice, expression of calbindin-D28k and parvalbumin were significantly increased while expression of calretinin was significantly decreased. These results suggest another mechanism by which NO can participate in the regulation of Ca2+ homeostasis.
Subject(s)
Animals , Mice , Calcium , S100 Calcium Binding Protein G , Calcium-Binding Proteins , Cerebellar Cortex , Cerebellum , Homeostasis , Immunohistochemistry , Neurons , Nitric Oxide , Nitric Oxide SynthaseABSTRACT
Hippocampal output is increased in affective disorders and is mediated by increased glutamatergic input via N-methyl-D-aspartate (NMDA) receptor and moderated by antidepressant treatment. Activation of NMDA receptors by glutamate evokes the release of nitric oxide (NO) by the activation of neuronal nitric oxide synthase (nNOS). The human hippocampus contains a high density of NMDA receptors and nNOS-expressing neurons suggesting the existence of an NMDA-NO transduction pathway which can be involved in the pathogenesis of affective disorders. We tested the hypothesis that nNOS expression is increased in the human hippocampus from affectively ill patients. Immunocytochemistry was used to demonstrate nNOS-expressing neurons in sections obtained from the Stanley Consortium postmortem brain collection from patients with major depression (MD, N = 15), bipolar disorder (BD, N = 15), and schizophrenia (N = 15) and from controls (N = 15). nNOS-immunoreactive (nNOS-IR) and Nissl-stained neurons were counted in entorhinal cortex, hippocampal CA1, CA2, CA3, and CA4 subfields, and subiculum. The numbers of Nissl-stained neurons were very similar in different diagnostic groups and correlated significantly with the number of nNOS-IR neurons. Both the MD and the BD groups had greater number of nNOS-IR neurons/400 µm² in CA1 (mean ± SEM: MD = 9.2 ± 0.6 and BD = 8.4 ± 0.6) and subiculum (BD = 6.7 ± 0.4) when compared to control group (6.6 ± 0.5) and this was significantly more marked in samples from the right hemisphere. These changes were specific to affective disorders since no changes were seen in the schizophrenic group (6.7 ± 0.8). The results support the current view of the NMDA-NO pathway as a target for the pathophysiology of affective disorders and antidepressant drug development.
Subject(s)
Adult , Female , Humans , Male , Middle Aged , Bipolar Disorder/enzymology , Depressive Disorder, Major/enzymology , Hippocampus/enzymology , Nitric Oxide Synthase Type I/metabolism , Schizophrenia/enzymology , Bipolar Disorder/physiopathology , Case-Control Studies , Depressive Disorder, Major/physiopathology , Hippocampus/physiopathology , Immunohistochemistry , N-Methylaspartate/metabolism , Schizophrenia/physiopathology , Signal Transduction/physiologyABSTRACT
PURPOSE: Nitric oxide synthase(NOS) is an important enzyme in the production of nitric oxide(NO). The constitutive type(cNOS) is expressed in the normal physiologic state, and the inducible type(iNOS) in expressed in the active immune state. cNOS is divided into an endothelial type (eNOS) and a neuronal type(nNOS). eNOS affects blood vessels, while nNOS affects nerve fibers. In the present study, we evaluated the expression of eNOS and nNOS in rat bladders with short-term partial outlet obstructions. We presupposed that NO is responsible for prolonged micturition problems after partial outlet obstruction. MATERIALS AND METHODS: Specific pathogen-free Sprague-Dawley rats weighing 250-300g were used for the study. Individual bladders were obtained from sham-operated control rats(n=5) and from experimental rats at 12 hours and 1, 2, 3, and 7 days after partial urethral obstruction(n=25). eNOS and nNOS were detected using immunochemical staining and analyzed with confocal microscopy and an image analyzer. RESULTS: eNOS and nNOS expression were detected in both the control group and in the group with partial outlet obstruction. The expression of eNOS showed a sharp increase at 3 days after obstruction and returned to normal at 7 days. The expression of nNOS was not significantly different between the two groups. CONCLUSIONS: In this study, we showed that eNOS increases in the rat bladder after partial outlet obstruction. This finding suggests that overproduction of NO may be the result of ischemic injury sustained during partial bladder outlet obstruction.
Subject(s)
Animals , Rats , Blood Vessels , Microscopy, Confocal , Nerve Fibers , Neurons , Nitric Oxide , Nitric Oxide Synthase Type I , Nitric Oxide Synthase Type III , Rats, Sprague-Dawley , Urinary Bladder , UrinationABSTRACT
Here, we investigated the temporal change of post synapse signaling molecules, post synaptic density-95 (PSD-95) and neuronal nitric oxide synthase (nNOS) using immunohistochemistry during voluntary running with upregulated neurogenesis. Rate of running was stabilized after two weeks of the six week trial. By using immunohistochemsitry for phosphorylated cAMP response element binding protein (pCREB) and polysialylatedneural cell adhesion molecules (PSA-NCAM), we observed that the differentiation in dentate granule cells of adult mouse hippocampus increased at 1 and 2 weeks of voluntary running. We found that, at 6 weeks of voluntary running, the differentiation in dentate granule cells of adult mouse hippocampus returned to sedentary control levels. On the other hand, PSD-95 and nNOS immunoreactivity decreased in the inner molecular layer in the dentate gyrus of hippocampus after 1 and 2 weeks of voluntary running. At 6 weeks of voluntary running, the density of the PSD-95 and nNOS in the inner molecular layer was returned to the sedentary control level. The reactivity of nicotinamide dinucleotide phosphate diaphorase (NADPH-diaphorase), the marker of nitric oxide synthase activity, confirmed the change of nNOS in the inner molecular layer during voluntary running. These results demonstrate that the differentiation and the synaptic activity of granule cells during voluntary running are changed reciprocally once the rate of running has stabilized. These granule cell changes during voluntary running suggest an adaptation response to the new environment.
Subject(s)
Adult , Animals , Humans , Mice , Cell Adhesion Molecules , Cyclic AMP Response Element-Binding Protein , Dentate Gyrus , Hand , Hippocampus , Immunohistochemistry , Neurogenesis , Neurons , Niacinamide , Nitric Oxide Synthase , Nitric Oxide Synthase Type I , Running , SynapsesABSTRACT
[Objective] The aim of this study was to investigate the effects of Joksamni (ST 36) combination on NADPH-diaphorase, neuronal nitric oxide synthase (nNOS), neuropeptide Y (NPY) and vasoactive intestinal peptide (VIP) in the cerebral cortex of spontaneously hypertensive rat. <BR>[Methods] The experimental groups were divided into four groups : Normal, Joksamni (ST 36), Joksamni (ST 36) + Eumneungcheon (SP 9), and Joksamni (ST 36) + Gokji (LI 11). Needles were inserted into acupoints at the depth of 0.5 cm with basic insertion method. Electroacupuncture was done under the condition of 2 HZ electrical biphasic pulses with continuous rectangular wave lasting for 0.2 ms until the muscles produced visible contractions. Such stimulation was applied continuously for 10 minutes, 1 time every 2 days for 10 sessions of treatments. Thereafter we evaluated changes in NADPH-d positive neurons histochemically and changes in nNOS, NPY and VIP positive neurons immunohistochemically. <BR>[Results] The optical densities of NADPH-d positive neurons of the Joksamni (ST 36) + Eumneungcheon (SP 9) group in all areas of cerebral cortex and Joksamni (ST 36) + Gokji (LI 11) group in primary somatosensory cortex, visual cortex, auditory cortex, perirhinal cortex were significantly increased as compared to the Joksamni (ST 36) group. <BR>The optical densities of NADPH-d positive neurons of the Joksamni (ST 36) + Gokji (LI 11) group were sig-nificantly decreased as compared to the Joksamni (ST 36) + Eumneungcheon (SP 9) group with the exception of primary somatosensory cortex. <BR>The optical densities of nNOS positive neurons of the Joksamni (ST 36) + Eumneungcheon (SP 9) group in all areas of cerebral cortex and Joksamni (ST 36) + Gokji (LI 11) group in auditory cortex, perirhinal cortex, insular cortex were significantly increased as compared to the Joksamni (ST 36) group. The optical densities of nNOS positive neurons of the Joksamni (ST 36) + Gokji (LI 11) group were significantly decreased in all areas of cerebral cortex as compared to the Joksamni (ST 36) + Eumneungcheon (SP 9) group. <BR>The optical densities of NPY positive neurons of the Joksamni (ST 36) + Gokji (LI 11) group were signifi-cantly decreased in primary motor cortex, primary somatosensory cortex, cingulate cortex as compared to the Joksamni (ST 36) and Joksamni (ST 36) + Eumneungcheon (SP 9) groups. <BR>The optical densities of VIP positive neurons of the Joksamni (ST 36) + Eumneungcheon (SP 9) group were significantly increased in all areas of cerebral cortex except f or cingulate cortex as compared to the Joksamni (ST 36) group. The optical densities of VIP positive neurons of the Joksamni (ST 36) + Gokji (LI 11) group were significantly decreased in auditory cortex, cingulate cortex, perirhinal cortex as compared to the Joksamni (ST 36) + Gokji (LIII) group were significantly decreased in all areas of cerebral cortex as compared to the Joksamni (ST 36) + Eumneungcheon (SP 9) group. <BR>[Conclusions] The result demonstrated that electroacupuncture on Joksamni (ST 36) and its combination change the activities of the NO system and peptidergic system in the cerebral cortex of SHR and that acupoint combination is one of the important parameters for the effects.
ABSTRACT
This study was conducted to define the molecular mechanism of fasting-induced down-regulation of neuronal nitric oxide synthase (nNOS) expression in the hypothalamic paraventricular nucleus (PVN). Rats were adrenalectomized (ADX), and then either underwent food deprivation or received varying doses of dexamethasone for 48 h. The brain tissues were processed for NADPH-diaphorase (NADPH-d) staining, a histochemical marker of nNOS enzyme activity. Both the ADX and the sham operated rats showed a significant weight loss after 48 h of food deprivation. Food deprivation decreased the number of NADPH-d containing cells in the PVN of sham rats, however, not in the ADX rats. Dexamethasone dose- dependently decreased NADPH-d cells in the PVN of ADX rats. The effect of ADX or dexamethasone was limited to the parvocellular subdivision of PVN. These results suggest that the adrenal glucocorticoids may down-regulate nNOS expression in the PVN during food deprivation.
Subject(s)
Animals , Male , Rats , Adrenalectomy , Biomarkers , Dexamethasone/blood , Down-Regulation/physiology , Fasting/physiology , Food Deprivation/physiology , Glucocorticoids/blood , NADPH Dehydrogenase/metabolism , Nitric Oxide Synthase/metabolism , Paraventricular Hypothalamic Nucleus/enzymology , Rats, Sprague-DawleyABSTRACT
In this study, we examined if glucocorticoids are required for the fasting-induced decrease of neuronal nitric oxide synthase (nNOS) in the magnocellular division of the paraventricular nucleus (PVN). Rats were adrenalectomized, subjected to 48 h of food deprivation with/without dexamethasone (5 mg/ kg, 4 subcutaneous injections with 12 h intervals), and the brain slices were processed for NADPH-diaphorase (NADPH- d) staining, a histochemical marker for nNOS in neuronal cells. In food deprived adrenalectomized rats, but not in free fed intact rats, dexamethasone significantly decreased NADPH-d staining in the magnocellular PVN. We previously reported that food deprivation decreases nNOS in the magnocellular PVN of intact rats. Thus, the present results together with our previous report suggest that although glucocorticoids are required for fasting-induced nNOS down-regulation in the magnocellular PVN, glucocorticoids may not be directly involved and some other molecular signals produced by food deprivation may play a pivotal role over glucocorticoid in the regulatory pathway for nNOS expression in this brain region.