[A 65-year-old man with Parkinsonism, gaze palsy, and dementia]

We report a 65-year-old man with parkinsonism, supranuclear gaze palsy, and dementia. The patient was well until 58 years of the age (1984) when he noted an onset of tremor in his right hand. He visited our neurology service two years after the onset; neurologic examination at that time revealed moderate restriction in down ward gaze, horizontal gaze nystagmus in left and right gaze, stooped posture with loss of arm swing when he walked, slight rigidity in the neck and the right upper and lower extremities, and resting tremor in his right hand and foot; mentation was intact. He was treated with 600 mg of levodopa with carbidopa; his tremor partially improved. He received left Vim thalamotomy on March 14 of 1987. His tremor disappeared after the thalamotomy. Post-operative course was complicated by transient clouding of consciousness due to subdural hematoma which developed after the surgery. Six months after the surgery, he noted increase in the unsteadiness of gait; he also experienced urinary incontinence once in a while, and he became mentally dull. In November of 1988, he had episodes of stiffening of his body. Although his spontaneous speech was very much reduced, he repeatedly hummed a same tune; no one could make him stop humming. In June of 1989, he was totally unable to move his eyes in the vertical direction. He was hospitalized to another hospital in May of 1990 where he died six month after admission because of pneumonia. The clinical course of this patient was characterized by the onset with parkinsonian resting tremor, and supranuclear gaze palsy and dementia in the later course. The patient was discussed in a neurological CPC and the chief discussant arrived at the conclusion that the patient had an overlap syndrome of progressive supranuclear palsy (PSP) and diffuse Lewy body disease. Majority of the participants thought that the patient had progressive supranuclear palsy, but many of them had an impression that parkinsonian tremor responding to levodopa as the initial symptom for PSP is rather unusual. Postmortem examination revealed severe loss of neurons in the substantia nigra, the globus pallidus, and the subthalamic nucleus with reactive gliosis; formy spheroids were seen in the substantia nigra, however, no Lewy bodies or neurofibrillary tangles were observed. Moderate neuronal loss was also seen in the dentate nucleus of the cerebellum. In addition, the precentral gyrus showed moderate neuronal loss, astrocytosis, and spongy change in the second layer; ballooned neurons were seen in the third and the fifth layers. Histologic characteristics were consistent with the pathologic diagnosis of corticobasal degeneration.

[Subarachnoid administration of lidocaine reduces delayed neuronal damage due to forebrain ischemia in rats]

We examined the effect of subarachnoid administration of lidocaine on delayed neuronal damage due to forebrain ischemia in rats. Sixteen rats were divided at random into two groups: lidocaine group rats (n = 8) and control group rats (n = 8) were subarachnoidally administrated lidocaine 5mg.kg-1 and normal saline, respectively, prior to ischemia. Forebrain ischemia was induced by bilateral carotid artery occlusion combined with systemic hypotension for 10 min. Cerebral perfusion-fixation was performed 7 days after ischemia, subsequent to which the brains were sectioned coronally and stained with celestine blue/acid fuchsin. In the neocortex and the hippocampal CA4 region, the lidocaine group showed less ischemic neuronal injuries than the control group. However, in the hippocampal CA1/CA3 regions and the caudoputamen, neuronal injuries in the lidocaine group were not significantly different from those in the control group. We conclude that the pre-ischemic subarachnoid administration of lidocaine reduces the delayed neuronal damage in neocortex and hippocampal CA4 region in the rat with forebrain ischemia.

Hemostasis with endoscopic hemoclipping for severe gastrointestinal bleeding in critically ill patients

OBJECTIVES

The fact that endoscopic hemostasis is difficult to achieve and that the rebleeding rate is high in critically ill patients with gastrointestinal bleeding has often been reported. The purpose of this study was to examine the efficacy of endoscopic hemoclipping for gastrointestinal bleeding from ulcers and gastrointestinal lesions associated with critical illnesses.

METHODS

Critically ill patients who were treated in a university hospital were studied prospectively. For patients with predefined clinically significant gastrointestinal bleeding, an established protocol of endoscopic hemoclipping (including indications and procedures) was used.

RESULTS

Ten of 885 patients were treated according to this protocol. All suffered circulatory collapse, and respiratory management required intubation. The initial rate of hemostasis was 100%, and no rebleeding was observed. The APACHE III scores at 24 h after hemostasis were reduced, relative to the time of bleeding (p < 0.01).

CONCLUSION

Endoscopic hemoclipping is useful in achieving hemostasis in critically ill patients with severe gastrointestinal bleeding.

Immunochemical and immunohistochemical localization of Bcl-x protein in the rat central nervous system

To explore the role of bcl-x in the regulation of cell death in the nervous system, we produced monoclonal antibodies against rat Bcl-xL protein, the major product of the rat bcl-x gene that inhibits apoptosis, and defined its distribution in rat neural tissues by immunochemical and immunohistochemical means. Western blotting of tissue homogenates identified the Bcl-x protein as two bands with molecular weights of about 29 and 31 kDa. The level of Bcl-x expression in the nervous system was high, being comparable to that in the hematolymphoid system, and higher in the fetal than in the adult brain. Subcellular fractionation studies localized Bcl-x to various subcellular compartments. In tissue culture, Bcl-x was produced by all the cell types examined, including neurons, astrocytes, oligodendrocytes and microglial cells. Immunohistochemistry revealed that Bcl-x immunoreactivity was more intense in the gray than in the white matter. In the fetal cerebral cortex, labeling was mostly confined to the neuronal perikarya, whereas in the more mature brain, the neuropil of the gray matter, as well as the glial cells in the white matter, was also stained.

Ciliary neurotrophic factor attenuates spatial cognition impairment, cortical infarction and thalamic degeneration in spontaneously hypertensive rats with focal cerebral ischemia

Ciliary neurotrophic factor (CNTF) has been shown to exhibit potent neurotrophic activity on peripheral and central neurons in vitro and in vivo. However, it remains to be determined whether or not CNTF rescues neuronal loss due to focal cerebral ischemia and prevents ischemia-induced disability of space navigation in rats. In the present in vivo study, we infused CNTF continuously for 4 weeks into the lateral ventricle, starting just after permanent occlusion of the left middle cerebral artery (MCA) of stroke-prone spontaneous hypertensive rats. CNTF infusion prevented the occurrence of ischemia-induced learning disability in a dose-dependent manner in rats subjected to the Morris water maze task. Subsequent histological examinations showed that cortical infarction and retrograde degeneration of the ipsilateral thalamic neurons in ischemic rats infused with CNTF were significantly less severe than those in ischemic rats infused with vehicle alone. These findings suggest that postischemic CNTF treatment prevents the occurrence of spatial learning disability in rats with permanent MCA occlusion, possibly by reducing neuronal damage within the cerebral cortex and secondary retrograde degeneration of the thalamus.

Monitoring urinary levels of monocyte chemotactic and activating factor reflects disease activity of lupus nephritis

Monocytes/macrophages (M phi) have been implicated in the pathogenesis of lupus nephritis (LN), but the precise molecular mechanism of recruitment and activation of M phi in LN remains unclear. To clarify the involvement of chemotactic cytokines (chemokines) in those events, we measured levels of monocyte chemotactic and activating factor (MCAF, also termed monocyte chemoattractant protein-1, MCP-1) in urines and sera derived from 42 patients with LN. Both urinary and serum MCAF levels were significantly higher in patients with LN as compared with 22 healthy volunteers (10.3 +/- 3.2 vs. 1.0 +/- 0.1 pg/ml . creatinine, 212.2 +/- 75.8 vs. 66.1 +/- 15.5 pg/ml, respectively, P < 0.05, mean +/- SEM). Histological examination of renal lesions from 41 patients classified 19 as active according to the WHO-defined classes IIIb, IVb and IVc, and 22 as inactive by the WHO-defined classes I, II, IIIc, IVd and V. Urinary MCAF levels in the patients with active lesions were significantly higher than those with inactive lesions (20.3 +/- 6.4 vs. 1.7 +/- 0.3 pg/ml . creatinine, P < 0.01). Moreover, elevated urinary MCAF levels were dramatically decreased during steroid therapy-induced convalescence in 29 patients examined serially (13.9 +/- 4.5 vs. 5.3 +/- 1.7 pg/ml . creatinine, P < 0.001), whereas serum MCAF levels did not change significantly. Endothelial cells, renal epithelial cells and infiltrating mononuclear cells in the tubulointerstitial regions were MCAF-positive in immunohistochemical as well as in situ hybridization analysis. These observations suggest that MCAF is probably involved in the pathogenesis of LN with active lesions, possibly through the recruitment and activation of M phi, and that measurement of urinary MCAF levels may be a useful clinical tool for monitoring the disease activity of LN.

Increased expression of carnitine palmitoyltransferase I gene is repressed by administering L-carnitine in the hearts of carnitine-deficient juvenile visceral steatosis mice

The juvenile visceral steatosis (JVS) mouse is a novel mutant animal for studying systemic carnitine deficiency. The importance of the model has been pointed out in carnitine-deficient cardiac hypertrophy, since cardiomyopathy has been often improved after oral carnitine therapy in human systemic carnitine deficiency. To understand the effects of carnitine deficiency on gene expression in the heart, we tried to find the genes regulated by carnitine by means of a modified differential display procedure. Carnitine palmitoyltransferase I (CPT I) was one of the isolated genes. The level of CPT I gene expression in the ventricles of the JVS mice was at least three- to sixfold that of normal mice as judged by reverse transcription-polymerase chain reaction (RT-PCR). When the JVS mice were treated with carnitine, CPT I gene expression was repressed to the level of normal mice. Therefore, the increased expression of the CPT I gene was associated with carnitine deficiency.

Comparative fungicidal activity of a new quaternary ammonium salt, N-alkyl-N-2-hydroxyethyl-N,N-dimethylammonium butyl phosphate and commonly used disinfectants

We synthesized a new quaternary ammonium salt, N-alkyl-N-2-hydroxyethyl-N, N-dimethylammonium butyl phosphate (ABP) that does not precipitate in the presence of anionic surfactants by incorporating a paired butyl phosphate anion into cationic surfactants. ABP showed much greater bactericidal activities and antirusting effects than benzalkonium chloride (BAC). In this study, the fungicidal effects of ABP were evaluated in comparison with common disinfectants [BAC, chlorhexidine digluconate (CHX) and alkyldiaminoethylglycine hydrochloride (ADE)]. Fungicidal effects were evaluated in 10 strains of 6 fungal species, namely, 3 Candida albicans, 2 Candida tropicalis, 1 Candida parapsilosis, 1 Aspergillus niger, 2 Aspergillus terreus, and 1 Trichophyton rubrum. ABP and BAC showed the same effects on 2 C. tropicalis and C. parapsilosis, and similar effects on 3 C. albicans, with slight differences among the strains. ABP showed quick fungicidal effects against A. niger and 2 A. terreus of molds in 30 min at 0.1% and in 15 min at 0.2 and 0.4%, but BAC showed slow effects against A. niger at 1 h and 2 A. terreus at 30 min at 0.2 and 0.4%, respectively. There is one factor, which may have caused this difference: the former had a butyl phosphate anion and the latter had a chloride anion as a counter ion. BAC, CHX and ADE needed 24h to cause notable effects on A. niger at 0.1% and 1 h at 0.2%. The new synthetic anti-rust ABP is considered to have sufficient fungicidal effects that are comparable to those of BAC, CHX and ADE.

High expression of Bcl-x protein in the developing human cerebellar cortex

The gene bcl-x, which is related to a bcl-2, regulates programmed cell death. bcl-x may function in the development of the nervous system. We raised a polyclonal antibody against human Bcl-x protein, and investigated its distribution in the developing human cerebellum. Western blotting revealed that Bcl-x expression in the cerebellum is higher in the fetal, than in the postnatal period. Immunohistochemical studies of fetal brains localized intense Bcl-x immunoreactivity in the granule cell processes at 13-22 gestational weeks and in the Purkinje cell bodies at 24-38 weeks. The immunoreactivity decreased after birth, but was retained in the Purkinje cells at a low level until adulthood. These results suggested that Bcl-x expression in the cerebellum is developmentally regulated and involved specifically in the development of neuronal subpopulations.

Origins of nitric oxide synthase-containing nerve fibers in the rat basilar artery with reference to the fine structure of the nerve fibers

The origins of nitric oxide synthase (NOS)-containing nerve fibers in the rat basilar artery were studied by a combination of Fluoro-Gold retrograde tracing and immunohistochemistry. After application of Fluoro-Gold onto the middle part of the basilar artery, the dye accumulated in the sphenopalatine, otic, trigeminal, superior cervical, nodose ganglia and in the spinal ganglia at level C2 and C3. Nerve cells with NOS-like immunoreactivity were detected in the above ganglia, except for the superior cervical ganglion. Neurons that showed both NOS-like immunoreactivity and Fluoro-Gold fluorescence were numerous in the sphenopalatine and otic ganglia, and less numerous in the trigeminal, nodose and spinal ganglia. Under electron microscopy, a number of unmyelinated nerve terminals with neuronal NOS-like immunoreactivity was seen in proximity to smooth muscle cells in the tunica media of the basilar artery. These findings provide morphological evidence that NOS-containing nerve fibers in the rat basilar artery have multiple origins, and suggest that the control of posterior cerebral circulation by the parasympathetic and sensory ganglia are more complex than previously considered.

Laparoscopic varicocele ligation

Varicocele, an abnormal dilatation of the pampiniform plexus, frequently contributes to male factor infertility. We performed laparoscopic varicocelectomy in 20 patients with varicoceles and abnormal seminal findings. The spermatic artery was identified and preserved in 13 patients and was clipped along with the veins in 7 patients including 1 patient with bilateral varicocele. The time required for the artery-ligating surgery ranged from 90 to 120 minutes with an average of 113.2 minutes, while the time needed for the artery-preserving technique ranged from 90 to 250 minutes with an average of 158.0 minutes. Some analgesics were administered to 11 patients, while the other 9 patients needed no analgesics. All patients were able to walk within 24 hours of the operation. The mean hospitalization period after the operation was 5.9 days. Sperm concentrations significantly improved postoperatively (p < 0.05). No difference in postoperative improvement of seminal findings was observed between artery-ligating and artery-preserving groups. A slight scrotal emphysema developed during the operation in 1 patient. Abdominal pain was experienced in 1 patient, but subsided within a few days. No serious complications were observed. The laparoscopic technique may replace routine open high ligation as the surgical treatment of choice, especially in patients with bilateral varicocele.

[Stimulus effect of submaximal trains of impulses on nerves]

Although the occurrence of rate-dependent conduction block upon exposure to supramaximal stimuli is a well-known phenomenon, changes in the stimulus effect of submaximal trains of impulses on nerves remain unknown. To investigate changes in the stimulus effect, we evaluated median nerve action potentials using various frequencies of impulse trains. The subjects were 12 healthy controls and 9 patients with diabetic polyneuropathy. A tungsten microelectrode was inserted into the median nerve trunk at the elbow. Weak stimuli that produced 10 microV compound nerve action potentials were repeated. Each value recorded is the average of 20 trials. Repetition of 1- to 5-Hz stimuli yielded the same average wave, but above 7-Hz, the stimuli produced a diminution in amplitude and slight prolongation of the latency of each peak. This was most prominent with 50-Hz or 100-Hz repeated stimuli. The potentials changed amplitude with a waxing and waning pattern, and gradually stabilized at a lower level. The averaged wave corresponded to the record of reduced stimuli at 0.6 mA, maximally. Paired stimuli at an interval of less than 5 msec were equivalent to a relative refractory period, whereas at an interval of 4-18 msec they were equivalent to a supernormal period, and at 12-90 msec, to a subnormal period. The 'jumping' (unexpected shortening of the latency of a potential in response to increased stimulus intensity) of a single nerve unit was provoked or released corresponding to these periods. No differences were found between healthy individuals and patients with diabetic polyneuropathy. As a consequence of electrogenic Na+/K+ pumping, a three-Na+ ion efflux occurred instead of a two-K+ ion influx. Thus, repeated high-frequency impulses induced membrane hyperpolarization that reduced the stimulus effect on nerves. With trains of impulses at a frequency of 100-Hz, which corresponds to a stimulus every 10 msec, the second response was greater than the first, reflecting the supernormal period, but impulse trains provoked hyperpolarization, as mentioned above, and reduced the amplitude of nerve action potentials. The results of this study show that the stimulus effect on nerves decreased at submaximal stimuli greater than 7-Hz, which reduced the amplitude of compound nerve action potentials. Therefore, averaging should be done at a stimulus frequency below 6-Hz.

Malignant mesenchymoma arising from the prostate in Gardner's syndrome

The first case of a primary malignant mesenchymoma arising from the prostate in Gardner's syndrome is reported. The neoplasm occurred in a 40-year-old man with a chief complaint of urinary retention. Biopsy findings were primary malignant mesenchymoma. Total cystectomy and lymphadenectomy were performed, but the patient died due to multiple metastases within 6 months. He had undergone a colectomy for polyposis coli 17 years earlier and had mandibular osteomas. This was the first case of malignant mesenchymoma arising from the prostate in Gardner's syndrome.

Structural elucidation of two novel amphoteric glycosphingolipids from the earthworm, Pheretima hilgendorfi

The novel amphoteric glycosphingolipids containing a choline phosphate were purified from whole tissues of the earthworm, Pheretima hilgendorfi. Their chemical structures were completely characterized as cholinephosphoryl-->6(Man alpha 1-4)Gal beta 1-6Gal beta 1-1Cer (cholinephosphorylmannosylneogalabiaosylceramide, named PGL3a) and cholinephosphoryl-->6Gal beta 1-6Gal beta 1-6Gal beta 1-1Cer (cholinephosphorylneogalatriaosylceramide, named PGL3b) by compositional sugar, fatty acid and sphingoid analyses, hydrogen fluoride degradation, partial acid hydrolysis, methylation analysis, exoglycosidase degradation, proton magnetic resonance spectroscopy and fast atom bombardment mass spectrometry. The ceramide moieties of these lipids consisted of 22:0, 23:0 and 24:0 acids as major fatty acids, and branched octadeca- and nonadeca-4-sphingenines and octadeca-4-sphingenine as main sphingoids. Since the oligosaccharides and the ceramide moieties of PGL3a and PGL3b were identical with those of neutral glycosphingolipids found in this organism, the biosynthesis of the amphoteric glycolipids may occur by the addition of a choline phosphate residue to the corresponding neutral glycolipids, Man alpha 1-4Gal beta 1-6Gal beta 1-1Cer or Gal beta 1-6Gal beta 1-6Gal beta 1-1Cer.

Development of near-field optic/atomic force microscope for biological materials in aqueous solutions

This paper reports improvements of optical fiber cantilevers and the scanning near-field optical microscopy imaging of biological materials in liquid. In our scanning near-field optical/atomic-force microscope (SNOAM), the scanning of an optical fiber cantilever over the specimen was controlled by dynamic mode AFM to reduce damage to the probe and soft specimens. The typical resonant frequency of the optical fiber cantilever was 19.5 kHz, while it was 23.0 kHz in air. The Q-factor of the cantilever depended on the vibration amplitude and was typically 260-600 in air and 40-240 in water. The relationship between the vibration amplitude and the average sample-probe separation indicated that the cantilever worked in the non-contact mode in water, while it worked in the cyclic-contact mode in air. Cultured cells in aqueous solutions were visualized by the SNOAM, indicating that the SNOAM is suitable to observe soft specimens.

[The internal thoracic artery of poor quality: was cardiac massage a cause of ITA stenosis?]

The case of stenotic left internal thoracic artery (LITA), with a very rare and interesting histological findings is reported. The patient, a 65-year-old man, fell into shock, due to acute myocardial infarction and received cardiopulmonary resuscitation at home immediately. Three months later, patient underwent coronary artery bypass grafting. The LITA was dissected from the chest wall with a tissue pedicle by usual manner. However, it was abandoned to use for grafting, because of extremely poor blood flow even after balloon dilatation was noticed. Histological study revealed a significant granulation of LITA media, led to severe stenosis of LITA lumen on it's portion. On other side, either proximal and distal portion of LITA remained intact. It seems that this unusual histological change of LITA media developed after LITA over stretching due to cardiac massage during cardiopulmonary resuscitation. If patient, scheduled for coronary bypass surgery, has in a personal history the presence of cardiac massage, traffic accident, some contact sport or any other chest trauma, it is recommended to perform LITA angiography preoperatively, if an intention to use the LITA for coronary artery bypass grafting exists.

1-Benzyl-1,2,3,4-tetrahydroisoquinoline as a parkinsonism-inducing agent: a novel endogenous amine in mouse brain and parkinsonian CSF

1-Benzyl-1,2,3,4-tetrahydroisoquinoline (1BnTIQ) was detected as a novel endogenous amine in mouse brain and parkinsonian CSF by using the gas chromatography-selected ion-monitoring method. The level of 1BnTIQ was very high in CSF of some parkinsonian patients compared with that of controls with other neurological diseases, the mean value being three times higher (parkinsonians: 1.17 +/- 0.35 ng/ml of CSF, n = 18; vs. controls: 0.40 +/- 0.10 ng/ml of CSF, n = 11; mean +/- SEM, not significantly different). The pole test, a toxicological examination to evaluate behavior abnormalities related to Parkinson's disease, was used to examine the pharmacological effect of 1BnTIQ in mice. Repeated administration of 1BnTIQ induced behavior abnormalities, which pretreatment with 1-methyl-1,2,3,4-tetrahydroisoquinoline could prevent. We suggest that 1BnTIQ may be related to the idiopathic Parkinson's disease.

Early detection of cerebral ischemic lesion using diffusion-weighted MRI

We performed serial diffusion-weighted imaging (DWI) in a patient with right middle cerebral arterial occlusion using 1.0 T MRI. The initial DWI demonstrated suppression of water diffusion in the gray matter in the ischemic lesion as a high signal area 4 h after stroke onset, when T2-weighted imaging failed to detect any parenchymal injury. Repeat DWI 9 h after onset demonstrated the whole infarct, whereas it was not demonstrated by T2-weighted imaging until 48 h. Furthermore, the regional apparent diffusion coefficient (ADC) had already decreased significantly in both the gray and white matters of the ischemic lesion 4 h after onset, even though hyperintensity was not visible in the white matter on the DWI. The features in this case indicate that DWI in conjunction with the assessment of regional ADC can provide important information regarding the evolving infarct at a very early stage even when a relatively low tesla clinically available MRI unit is used.

[Opioid receptors altered binding nature in guinea-pig brain following the development of morphine dependence]

Morphine is well known to produce tolerance and dependence. The mechanisms for these phenomena are not clearly understood and there are a number of conflicting reports that chronic morphine administration decreases, increases, or leaves unchanged the number of opioid binding sites. We examined the potency of MScontin (oral controlled-release preparation of morphine) to induce morphine dependence and also determined the change of mu, delta and kappa opioid receptor types in brain homogenates obtained from morphine-dependent guinea-pigs. 1. Guinea-pigs were implanted subcutaneously with MScontin (300 mg.kg-1) and naloxone was employed to precipitate jumping behavior of withdrawal symptoms at various times. The highest degree of physical dependence was observed on the 2nd day after implantation. Therefore, this period was chosen to investigate opioid receptor binding assay. 2. Two days after implantation, the binding of 3H-DAGO (mu agonist), 3H-DPDPE (delta agonist) and 3H-U69593 (kappa agonist) to brain membranes prepared from morphine dependent and control guinea-pigs was determined. Scatchard plot of the saturation binding data revealed an increase in Bmax values (maximum specific binding) and no change in the Kd values (equilibrium dissociation constants) of 3H-opioid ligand bindings obtained from morphine-dependent animals as compared to controls. These results indicate that brain mu, delta and kappa opioid receptors are up-regulated in morphine dependent guinea-pigs.

Role of basic fibroblast growth factor in the regulation of rat basilar artery tone in vivo

Using the cranial window method, we investigated the effect of basic fibroblast growth factor (bFGF) on the diameter of the rat basilar artery in vivo. bFGF (5-200 ng/ml) caused significant vasodilation in a dose-dependent manner with the maximal effect (119% of baseline diameter) at 200 ng/ml. Vasodilation was not observed when the basilar artery was treated with heat-inactivated bFGF or bFGF preincubated with bFGF-neutralizing monoclonal antibody. Moreover, bFGF-induced vasodilation was suppressed significantly by coadministration of the nitric oxide (NO) synthase inhibitor, NG-nitro-L-arginine methyl ester (L-NAME). In contrast, NG-nitro-D-arginine methyl ester (D-NAME), which is the isomer of L-NAME, exerted no influence on bFGF-induced vasodilation. These findings suggest that the dilatation by bFGF of the rat basilar artery is mediated by NO, and that bFGF plays an important role in the regulation not only of the anterior circulation as previously described but also of the posterior circulation in the brain.

Intraventricular administration of nitric oxide synthase inhibitors prevents delayed neuronal death in gerbil hippocampal CA1 neurons

We performed experiments to investigate the participation of nitric oxide (NO) in the delayed neuronal death (DND) of gerbil hippocampal CA1 neurons, following 5-min forebrain ischemia with pretreatment of stereotaxic intraventricular administration of several types of NO synthase inhibitors and biologically inactive control drugs. The number of surviving neurons in the control drug groups administered NG-monomethyl-D-arginine or NG-nitro-D-arginine methyl ester was comparable to that in the group administered artificial cerebro-spinal fluid, while the groups administered NOS inhibitors, such as NG-monomethyl-L-arginine or NG-nitro-L-arginine methyl ester, showed significant preservation of the neuronal densities compared with the control drug groups, to over 60% of the sham operation group value. Furthermore, intraventricular administration of N omega-nitro-L-arginine at various concentrations disclosed a dose-dependent protection against the DND. These results suggest that the generation of NO may act to promote the establishment of DND.