Opioid Analgesics and Depressive Symptoms in Burn Patients: What Is the Real Relationship?

OBJECTIVE: Major burn injuries are strongly associated with both psychological trauma and severe pain, and opioids are the mainstay analgesics for the treatment of severe burn pain. The objectives of this study are to find the complex relationship between opioid dose, depression, and post-traumatic stress disorder (PTSD) symptoms during the acute management of pain in burn patients. METHODS: The symptoms of depression and PTSD were assessed in 43 burn patients immediately following wound stabilization and 2 weeks after the initial evaluation. RESULTS: Total opioid doses and Hamilton Depression Scale (HAMD) scores obtained during the second evaluation were positively but weakly correlated after controlling for age and total burn surface area (R=0.33, p=0.03). Moreover, pain management with opioids was significantly more common in burn patients with low Clinician Administered PTSD Scale scores (evaluation 1) and high HAMD scores (evaluation 2) (F=6.66, p=0.001). CONCLUSION: High opioid dose following acute burn trauma might have correlation with depressive symptoms. Monitoring of depressive symptoms may be important following acute burn trauma and consequent opioids pain management, particularly when PTSD symptoms appear minimal during the early stabilization of patients.

The Current Situation of Treatment Systems for Alcoholism in Korea

Alcoholism is becoming one of the most serious issues in Korea. The purpose of this review article was to understand the present status of the treatment system for alcoholism in Korea compared to the United States and to suggest its developmental direction in Korea. Current modalities of alcoholism treatment in Korea including withdrawal treatment, pharmacotherapy, and psychosocial treatment are available according to Korean evidence-based treatment guidelines. Benzodiazepines and supportive care including vitamin and nutritional support are mainly used to treat alcohol withdrawal in Korea. Naltrexone and acamprosate are the drugs of first choice to treat chronic alcoholism. Psychosocial treatment methods such as individual psychotherapy, group psychotherapy, family therapy, cognitive behavior therapy, cue exposure therapy, 12-step facilitation therapy, self-help group therapy, and community-based treatment have been carried out to treat chronic alcoholism in Korea. However, current alcohol treatment system in Korea is not integrative compared to that in the United States. To establish the treatment system, it is important to set up an independent governmental administration on alcohol abuse, to secure experts on alcoholism, and to conduct outpatient alcoholism treatment programs and facilities in an open system including some form of continuing care.

The effects of electrical shock on the expressions of aquaporin subunits in the rat spinal cords / 대한해부학회지

We analyzed aquaporin (AQP) expression in the rat spinal cord following an electrical shock (ES) to elucidate the roles of AQP in spinal cord injury (SCI) induced by an electrical burn. In control animals, AQP1 immunoreactivity was observed in the small diameter dorsal horn fibers of laminae I and II and in astrocytes and neurons in the spinal cord. Both AQP4 and AQP9 immunoreactivity were detected in astrocytes. One week after the ES, AQP1 immunoreactivity in dorsal horn fibers was downregulated to 83, 61, and 33% of control levels following a 1-, 4-, or 6-second ES, respectively. However, AQP1 immunoreactivity in ventral horn neurons increased to 1.3-, 1.5-, and 2.4-fold of control levels following a 1-, 4-, or 6-second ES, respectively. AQP4 immunoreactivity was upregulated after an ES in laminae I and II astrocytes in a stimulus-intensity independent manner. Unlike AQP1 and AQP4, AQP9 immunoreactivity was unaffected by the ES. These findings indicate that altered AQP immunoreactivity may be involved in SCI following an ES.

Increased Transforming Growth Factor-beta1 in Alcohol Dependence

Ethanol and its metabolite acetaldehyde increase transforming growth factor beta1 (TGF-beta1) expression in animal studies. TGF-beta1 is related with the hepatic stellate cell (the key element of hepatic fibrogenesis) and the radial glia (the key element of neuronal migration). Blood samples were collected from 41 patients with alcohol dependence, TGF-beta1 levels measured by ELISA were compared with 41 normal subjects. Plasma TGF-beta1 levels in the patients with alcohol dependence (1,653.11+/-532.45 pg/mL) were significantly higher than those of healthy subjects (669.87+/-366.53 pg/mL) (P=0.000). Patients with or without liver pathology showed no difference in TGF-beta1 (P=0.36). Increased TGF-beta1 may mediate deleterious effect of alcohol such as hepatic fibrosis and suppressed neuronal developments in alcohol dependence patients.

Neuronal loss in primary long-term cortical culture involves neurodegeneration-like cell death via calpain and p35 processing, but not developmental apoptosis or aging

Primary neuronal culture is a powerful tool to study neuronal development, aging, and degeneration. However, cultured neurons show signs of cell death after 2 or 3 weeks. Although the mechanism underlying this phenomenon has not been elucidated, several preventive methods have been identified. Here we show that the neuronal loss in primary cortical culture involves calpain activation and subsequent neuronal cell death. Neuronal loss during cultivation showed destruction of neurites and synapses, and a decrease in neuron numbers. micro-Calpain and micro-calpain were initially activated and accumulated by increased RNA expression. This neuronal death exhibited neurodegenerative features, such as conversion of p35 to p25, which is important in the developmental process and in the pathogenesis of Alzheimer's disease. But, postnatal and aged rat cortex did not show calpain activation and prolonged processing of p35 to p25, in contrast to the long-term culture of cortical neurons. In addition, the inhibition of calpains by ALLM or ALLN blocked the conversion of p35 to p25, indicating that the calpain activity is essential for the neurodegenerative features of cell death. Taken together, this study shows that the neuronal loss in primary cortical cultures involves neurodegeneration-like cell death through the activation of calpains and the subsequent processing of p35 to p25, but not developmental apoptosis or aging. Our results suggest that the long term primary culture of cortical neurons represent a valuable model of neurodegeneration, such as Alzheimer's disease.

Immunolocalization of anion exchanger 1 (Band 3) in the renal collecting duct of the common marmoset

The purpose of this study was to determine the expression and distribution of band 3 in the collecting duct and connecting tubules of the kidney of the marmoset monkey (Callithrix jacchus), and to establish whether band 3 is expressed in type A intercalated cells. The intracellular localization of band 3 in the different populations of intercalated cells was determined by double-labeling immunohistochemistry. Immunohistochemical microscopy demonstrated that band 3 is located in the basolateral plasma membranes of all type A intercalated cells in the connecting tubule (CNT), cortical collecting duct (CCD), and outer medullary collecting duct (OMCD) of the marmoset. However, type B intercalated cells and non-A/ non-B intercalated cells did not show band 3 labeling. Electron microscopy of the CNT, CCD and OMCD confirmed the light microscopic observation of the basolateral plasma membrane staining for band 3 in a subpopulation of interacted cells. Basolateral staining was seen on the plasma membrane and small coated vesicles in the perinuclear structure, some of which were located in the Golgi region. In addition, there was no labeling of band 3 in the mitochondria of the CNT, CCD and in OMCD cells. The intensity of the immunostaining of the basolateral membrane was less in the CNT than in the CCD and OMCD. In contrast, band 3 immunoreactivity was greater in the intracellular vesicles of the CNT. From these results, we suggest that the basolateral Cl-/HCO3- exchanger in the monkey kidney is in a more active state in the collecting duct than in the CNT.

Immunoreactivity of Somatostatin Receptor Subtype 2 in Dorsal Root Ganglia in the Rat / 대한정형외과학회잡지

PURPOSE: Somatostatin has been suggested to play a role in the transmission of neurotransmitters and in the modulation of pain. Of the different subtypes of somatostatin receptors 2, sstr2A and sstr2B are important in the modulation and transmission of pain. The present study was carried out to investigate sstr2 immunoreactivity in rat. MATERIALS AND METHODS: Dorsal root ganglia (DRG) cells at the L4-L6 levels of the spinal cord of 10 rats (Sprague-Dawley, 200-250 g) were examined for sstr2 by immunohistochemistry. RESULTS: In the control group, sstr2A immunoreactivity was strongly positive in the dense network within laminae I and II of the dorsal horn at spinal levels (L4-L6). In contrast to sstr2A, sstr2B immunoreactivity was observed throughout laminae III-VI. In the DRG, sstr2A and sstr2B immunoreactivities were mainly found in medium-sized neurons. CONCLUSIONS: The distribution of sstr2A immunoreactive cells among sstr2 in the dorsal root ganglia (L4-6) resembles that of somatostatin. Incontrast to sstr2A, sstr2B immunoreactivity showed a different distribution. The presence of sstr2A at laminae I and II, and sstr2B at laminae III-VI of the dorsal horn may modulate sensory functions at these different regions of the spinal cord. Considering different actions according to the receptors of the neurotransmitter, the functions of the isoforms of sstr2 appear variable in terms of modulating and transmitting pain.

Age-Related Changes of Catalase Immunoreactivity in the Main Olfactory Bulbs of Wistar and Spontaneously Hypertensive Rats / 대한해부학회지

The reactive oxygen species (ROS) is well-known for the causative factors inducing ischemia, Parkinson's disease, Alzheimer, amylotrophic lateral sclerosis, hypertension and aging. Catalase (CAT) is an important endogenous antioxidant enzyme against ROS because it removes H2O2 during metabolic processes. Hence, we examined the age-related changes of CAT-immunoreactivity in the main olfactory bulbs (MOB) of the Wistar and spontaneous hypertensive rat (SHR) at various aging stages over 2 years periods; postnatal month 6 (PM 6), PM 12, PM 18 and PM 24. CAT immunoreactive (IR) neurons in Wistar rats were located in the glomerular layer (GL), external plexiform layer (EPL), internal plexiform layer (IPL) and granule cell layer (GCL). The number of CAT-IR neurons slightly decreased agedependently and nearly disappeared at PM 24. At PM 6 and PM 12, the CAT-IR neurons located in the EPL were morphologically identified as granule cells. However, at PM 18 and PM 24, CAT-IR neurons located in the EPL and mitral cell layer (MCL) were morphologically identified as tufted and mitral cells, respectively. CAT-IR neurons in the SHR were located in all layers of the MOB. The number of CAT-IR neurons and CAT immunoreactivity decreased agedependently and nearly disappeared especially in the GL and EPL at PM 24. These findings indicate that the decrease of CAT immunoreactivity may be one of the causative factors for increase of oxidative stress, and these damages may underlie age-related changes in the olfactory process. The early decrease of CAT immunoreactivity in the SHR than in the Wistar rat suggests that the early decreae of CAT may be associated with the cause of hypertensive neuronal damage.

Human glutamate dehydrogenase is immunologically distinct from other mammalian orthologues

Five monoclonal antibodies (mAbs) that recognize human glutamate dehydrogenase (GDH) have been selected and designated as monoclonal antibodies hGDH60-6, hGDH60-8, hGDH63-10, hGDH63-11, and hGDH91-14. A total of five mAbs recognizing different epitopes of the enzyme were obtained, two of which inhibited human GDH activity. When total proteins of human homogenate separated by SDS- PAGE, were probed with mAbs, a single reactive protein band of 55 kDa, which co-migrated with purified recombinant human GDH was detected. When the purified GDH was incubated with each of the mAbs, its enzyme activity was inhibited by up to 58%. Epitope mapping analysis identified, two subgroups of mAbs recognizing different peptide fragments. Using the individual anti-GDH antibodies as probes, the cross reactivities of brain GDH obtained from human and other animal brain tissues were investigated. For the human and animal tissues tested, immunoreactive bands on Western blots appeared to have the same molecular mass of 55 kDa when hGHD60-6, hGHD60-8, or hGHD91-14 mAbs were used as probes. However, the anti-human GDH mAbs immunoreactive to bands on Western blots reacted differently on the immunoblots of the other animal brains tested, i.e., the two monoclonal antibodies hGDH63-10 and hGDH63-11 only produced positive results for human. These results suggest that human brain GDH is immunologically distinct from those of other mammalian brains. Thorough characterization of these anti-human GDH mAbs could provide potentially valuable tool as immunodiagnostic reagents for the detection, identification and characterization of the various neurological diseases related to the GDH enzyme.

Origins of Dorsal Root Ganglion Cells with CGRP innervating Quadriceps Femoris Tendon of Rat / 대한정형외과학회잡지

PURPOSE: This study was undertaken to determine the origins of dorsal root ganglion (DRG) cells containing calcitonin gene-related peptide (CGRP) which innervate the quadriceps femoris tendon in the rat. MATERIALS AND METHODS: DRG cells containing CGRP, which innervate the quadriceps femoris tendon, from 25 rats (Sprague-Dawley, 200-250 g) were examined using the retrograde tracing technique (neural tracers: horseradish peroxidase and fluorogold) combined with immunohistochemistry. RESULTS: Injection of horseradish peroxidase (HRP) or fluoro-gold (FG) into the quadriceps femoris tendon resulted in the ipsilaterally labelling of cells between L1 and L6 DRGs. However, a large number of the labelled cells innervating the quadriceps femoris tendon were found in the L3 and L4 DRGs. Many DRG cells were immunostained with CGRP antibody in the L1-6 DRGs. The number of CGRP immunoreactive cells in the lumbar DRGs was larger than in the sacral DRG. FG labelled cells containing CGRP immunoreactivity (FG+CGRP cells) were found in the lumbosacral DRGs. Many FG+CGRP cells innervating the quadriceps femoris tendon were located in the L3 and L4 DRGs. CONCLUSION: These results show that the main DRG origin for the sensory innervation of the quadriceps femoris tendon is L3 or L4. The neurogenic pain of the quadriceps femoris tendon may originate from this region, and suggests that this may be important for the release of neurogenic pain.

The Distribution of CGRP Containing Cells Innervating the Calcaneal Tendon in Rat Dorsal Root Ganglia / 대한해부학회지

This study was performed to investigate origins of the dorsal root ganglion cells containing calcitonin gene -related peptide (CGRP) which innervate the calcaneal tendon in the rat. We used the horseradish peroxidase (HRP) or fluoro -gold (FG) to trace retrogradely somatic afferents in dorsal root ganglion cells after unilateral injections into the rat calcaneal tendon. HRP or fluoro -gold labeled DRG cells for the calcaneal tendon were seen generaaly in lumbosacral (L1 to S1) DRGs ipsilaterally. In lumbosacral DRGs, the largest number of labeled cells were found in the L6 DRG. Many DRG cell bodies contained the CGRP throughout the L1~S1. A plenty of HRP -or FG -labeled cells innervating the calcaneal tendon were also identified to contain the CGRP in L1~S1 DRGs. These FG +/- CGRP DRG cells innervating the calcaneal tendon were primarily found in the L6 DRG. These results suggest that the main sensory DRG for the calcaneal tendon is the L6. This fact may be available in diagnosis and treatment of neurogenic pain in the calcaneal tendon.

Chronological Alteration of Calbindin D-28k and Calretinin Immunoreactivity in the Gerbil Trigeminal Ganglion After Ischemia-Reperfusion / 대한해부학회지

Many researches have focused upon temporal changes of neurotransmitters and/or neuromodulators in the central nervous system after ischemic insult. In sensory neurons, the spatial and temporal alterations of neurotransmitters have been little studied. Calbindin D-28k (CB) and calretinin (CR) have been suggested to play a role in the transmission of neurotransmitters. Therefore, in the present study we investigated the chronological alteration of CB and CR immunoreactivity in the trigeminal ganglion cells of the Mongolian gerbil after ischemic insult. In the sham operated group, CB and CR immunoreactivities were found in small -, medium -and large -sized neurons. One and two days after ischemia-reperfusion, small and large-sized CB immunoreactive neurons increased significantly. Thereafter, number of the CB immunoreactive neurons decreased markedly. Furthermore, five days after ischemia -reperfusion, CB immunoreactivity was detected in a few neurons, and its immunoreactivity was also very weak in the cytoplasm. Number of the large -sized CR immunoreactive neurons increased significantly one day after ischemia -reperfusion. Thereafter, the number of the large -sized CR immunoreactive neurons decreased. Especially, the number of the medium-sized CR immunoreactive neurons increased dramatically 4 days after ischemia-reperfusion. These results suggest that an increase of CB and CR may play an important role in modulating the mechanoception 1 day after ischemia-reperfusion, because the immunoreactivities increased in large -sized neurons which have the myenlinated A fibers. These results also suggest that significant increase of CR expression in medium -sized neurons 4 and 5 days after ischemia-reperfusion may provoke CR in modulating the nociception or thermoception because the medium-sized neurons which have the myenlinated A sigma or C fibers.

Seizure Induced Alteration of Microtubule Associated Proteins Immunoreactivities in the Mongolian Gerbil Striatum / 대한해부학회지

The present study involves a chronological and comparative analysis of both microtubule-associated protein 1A (MAP1A) and microtubule-associated protein 2 (MAP2) immunoreactivities in the striatum of both seizure resistant (SR) and seizure sensitive (SS) gerbil. The MAP1A immunoreactivity is weakly detected in perikarya of SR gerbils. However, MAP1A immunoreactivity is more accumulated in perikarya and dendrites in the pre-seizure group. At 30 min postictal, MAP1A immunoreactivity in the perikarya is decreased. At 3 hr postictal, MAP1A immunoreactivity in perikarya and dendrites is similarly decreased to the level of SR gerbils. The MAP2 immunoreactivity is weakly detected in the perikarya and dendrites of SR gerbils. However, MAP2 immunoreactivity is more accumulated in perikarya and dendrites. In particular, the neuropil between unstained fiber tracts obviously contains strong MAP2 immunoreactivity. At 30 min postictal, MAP2 immunoreactivity isn't almost observed in striatum. At 3 hr postictal, the MAP2 immunoreactivity is not different in the 30 min post -seizure groups but is only observed in the neuropil. However, at 12 hr postictal, the decrease of both MAP1A and MAP2 immunoreactivities had recovered to the pre -seizure level of SS gerbils. These results suggest that MAPs immunoreactivity in the striatum is different in SR and SS gerbils, and that this difference may be the results of seizure activity in this animal.

Immunoreactive Change of Neuropeptides in Gastrocnemius Muscle and Dorsal Root Ganglia of Rat Followed by Ischemia

There are much evidences to indicate that muscles and its tendon are inserted during the reperfusion phase of ischemia-reperfusion insults. However, until now the alterations of neurotransmitter induced by ischemia- reperfusion have not been examined in peripheral nervous system. This study reports the alterations of calcitonin gene-related peptide(CGRP) and substance P(SP) in the hindlimb ischemic model by immunohistochemical methods. In the control group, the CGRP and SP immunoreactivity was observed in nerve terminals of gastrocnemius muscle and its tendon. In the dorsal root ganglia, CGRP immunoreactivity was shown in the large A cell and small B cell. On the other hand, SP immunoreactvity was predominantly detected in small B cells. The CGRP immunoreactivity in the gastrocnemius muscle increased significantly in 2 hour ischemic group, but decreased in its tendon. The SP immunoreactivity, however, was declined in the gastrocnemius muscle as well as its tendon in 2 hour ischemic group. The CGRP immunoreactivity in the dorsal root ganglia was significantly decreased, particularly in large A cell, compared to the control group. The SP immunoreactivity in the dorsal root ganglia, on the other hand, was markedly increased. In conclusion, these results suggest that the ischemia may evoke the alteration of neurotransmitter expressions as well as the muscle degeneration, and that the changes of neuropeptide distribution induced by ischemia show the difference from the kind of neuropeptides.

Immunohistochemical Study on the TfBP Expression in the Embryonic Chick Cerebellum / 대한해부학회지

We have previously demonstrated that transferrin binding protein (TfBP) is a reliable marker for mature oligoden-drocytes (OLGs) in the avian central nervous system (CNS). Unlike mammalian CNS in which OLGs are generated largely postnatally, avian OLGs are differentiated during embryonic development of CNS. In this study, several aspects of TfBP(+/-) OLG development were immunohistochemically examined in the embryonic chick cerebellum : (1) change in shapes of immature cells with respect to time and to location within the cerebellum, (2) possible sites of origin, and (3) pathways of precursor cell migration. Our results indicate that TfBP expression gradually increases and extends from the deep portion of the white matter to gray matter with proportion to progress of cerebellar development. A few TfBP? cells were first observed in the deep portion of the cerebellum at E9. At E13, TfBP(+/-) cells were distributed evenly within the white matter. At E17, many TfBP(+/-) OLGs were located at granular layer and at the near place of Purkinje cell layer. At E20, a large number of TfBP cells appeared at the granular layer with a few in the molecular layer. Our data demonstrated distinct patterns of morphology and location of TfBP(+/-) OLGs in the cerebellum during development and suggest a role of TfBP in OLG development.

The Alteration of Avian Retinal Microglia Induced by Optic Nerve Transection / 대한해부학회지

Retina, a part of CNS, has served valuable and accessible tissue for elucidating the cellular properties of neurons and glia due to its similarity to brain. Unlike mammalian counterpart, avian retina is devoid of vessels and astrocytes. However little is known about glial reaction to neuronal injuries in this species. Therefore, this study was performed to investigate the microglial responses in the quail retina following neuronal injuries. The retinae from normal and optic nerve transected adult quails were studied immunohistochemically with anti-QH1, a marker known to be specific for microglia. In the normal retina, QH1-labeled microglial cells displayed typical feature of ramified (resting) form and were localized mainly in the inner plexiform layer. After optic nerve transection (ONT) morphology of microglial cells changed from the ramified to the amoeboid form. This feature of microglial cells maintained throughout the post operational periods until 28 days after ONT. Particularly, at 14 and 21 days after ONT amoeboid microglia displayed cell bodies with stout and bushy processes, suggesting active phagocytosis. The distribution pattern of microglia also changed in accord to ganglion cell degeneration: they gradually moved to layers of ganglion cells and optic nerve fibers where ganglion cell bodies and axons were under degeneration. This change of microglial distribution was most prominent at 14 days of ONT. The result of this study is generally consistent with that reported in mammalian counterpart and this similarity between the avascular avian retina and the vascularized mammalian counterpart suggests that processes of microglial activation, such as migration and phagocytosis, can occur in the vessel-free CNS tissue.

Localization and mRNA Expression of Angiogenin in Bovine Ovary / 대한해부학회지

Ovary is one of the organs in which angiogenesis occurs during ovarian cycle. Angiogenesis is associated with angiogenic factor like acidic fibroblast growth factor, basic fibroblast growth factor and transformation growth factor. Therefore, we performed this study to identify the distribution and mRNA expression of angiogenin, new potential angiogenic factor, in ovary of Korean native cattle by immunohistochemistry and in situ hybridization. Angiogenin immunoreactivity and mRNA expression were observed in endothelial cells, fibroblast and vascular smooth muscle cells. However, we could not observed angiogenin immunoreactivity and mRNA expression in primordial ovarian follicle. In follicular epithelial cells of primary ovarian follicle, weak angiogenin immunoreactivity and mRNA expression were observed. Follicular epithelial cells, theca interna and externa in secondary ovarian follicles, showed angiogenin immunoreactivity, while follicular epithelial cells did the weak mRNA expression. Angiogenin immunoreactivity and mRNA expression were observed in follicular epithlial cells, theca interna and oocyte in tertiary ovarian follicle. The corpus luteum showed strong immunoreactivity and mRNA expression but atretic follicle weak. However, these angiogenin immunoreactivity and mRNA expression became to be weaker during regression. These results suggest that angiogenin may play a role as not only an angiogenic factor but a growth factor in ovary.

Carbonic anhydrase II immunostaining in the cerebellum of postnatal mice / 대한해부학회지

The carbonic anhydrase II (CA-II) is specifically expressed in oligodendrocytes, the cells responsible for myelination in the central nervous system. However no direct evidence on relationship between myelin formation and CA-II immunoreactivity has been described. The aims of these studies are to investigate the relationship between CA-II and myelination during cerebellar development of mouse. Myelin staining was found on postnatal (P) 14, and its intensity increased in proportion to developmental age. CA-II positive oligodendrocytes were observed in the white matter of cerebellum on P 14 day. CA-II positive oligoden-drocytes also occured in the granular layer and Purkinje cell layers in the later stage of dvelopment. The parallel development in the CA-II expression and myelination during development suggests that CA-II in oligoendrocyte play a role to myelination.

Cytotoxic Effect of 6-OHDA on the Dopaminergic Neurons and Astrocytes in the Dorsal Raphe Nucleus of the Rat / 대한해부학회지

This study was designed to clarify the cytotoxic effects of 6-hydroxydopamine (6-OHDA) on the dopaminergic neurons and astrocytes in the dorsal raphe nucleus (DRN), and to investigate neurodegenerative changes by immuno-histochemistry. Adult male rats (Sprague-Dawley strain) weighing from 250 to 350 g were used as experimental animals. 6-OHDA (100 micrometer dissolved in 0.1% ascorbic acid) was injected into the lateral ventricle of the rat brain with the Hamilton syringe. The control rats were treated with the similar volume of 0.1 % ascorbic acid. The rats were sacrificed at the 3rd, 5th, 10th and 20th day, respectively, after the injection of 6-OHDA. The cytotoxicity of 6-OHDA resulted in severe neurodegeneration of the dopaminergic neurons in the DRN. In the 3rd day, the dopaminergic fibers were dilated. In the 5th and 10th days, the dopaminergic fibers were depleted, and dopaminergic cell bodies were shrunken. In the 20th day, the dopaminergic cell bodies were almost completely disappeared. Astroglial reactions induced by 6-OHDA were also observed in the DRN. In the 5th day, astrocytes were significantly increased as compared with that of the control value. The value were reached at its maximum by the 20th day. Based on the present results, it suggests that 6-OHDA may act as a specific neurotoxin to dopaminergic neurons in the DRN, and induce severe neurodegenerative changes. Also, it suggests that the astroglial reaction in the DRN is gradually activated during the neurodegerative changes.

Expression of Guanine Deaminase in the Developing Rat Brain / 대한해부학회지

Guanine aminohydrolase (GAH; Guanine deaminase, EC 3.5.4.3) is an enzyme that has a role in purine catabolism. This enzyme produces xanthine and ammonia by hydrolysis of guanine, and xanthine is further degraded to uric acid and hydrogen peroxide by another enzyme, xanthine oxidase. Most of the enzymes involved in purine catabolism have been studied for their biological functions, physiological roles and amino acid sequences, and biochemical activity of GAH is known to be detected in various organs such as liver, kidney, small intestine and brain. Its activity is also known to be changed during brain development. In this study, we hoped to reveal expression pattern of GAH in developing rat brain by western blotting and immunohistochemistry. In western blotting, GAH immunoreactivity was not detected on 14-, 16- and 18-days-old fetal rat brains. Its reactivity was first detected from 20-days-old fetal rat brain and highly increased after birth. And it was maintained at steady level from 2 weeks after birth. In immunohistochemistry, no positive cells were found on 14- and 16-days-old fetal rat brain sections. A few GAH-immunoreactive cells appeared from 18-days-old fetal rat brain and they were localized at olfactory bulb, cerebral cortex, midbrain, pons and medulla. The 20-days-old fetal rat brain also showed immunoreactive cells at hippocampus and the staining intensity was still weak. Postnatal 2-days-old rat brain also showed immunoreactive cells at basal ganglia and the number of positive cells and staining intensity were increased. Thereafter, immunoreactivity appeared on many neuronal cells around various areas in the brain and nerve fibers also showed reactivity on postnatal brains. The number of positive cells decreased from 1 week after birth and a few positive cells were observed on olfactory bulb and cerebellum from 2 weeks after birth. In mature brain most of GAH were localized on nerve fibers and few positive cells could be found on olfatory bulb only. From these, we can suspect that GAH may have some functional relationship with nerve fibers.