The effects of iloprost, a prostacyclin analogue, in experimental ischaemia/reperfusion injury in rat ovaries

Ovarian torsion is a surgical emergency affecting not only the ipsilateral ovary but also contralateral ovary. Although the conventional treatment is salpingo-oophorectomy, recent studies advocate detorsion. We hypothesized that iloprost, an analogue of prostacyclin with cytoprotective properties, may prevent the harmful effects of ischaemia–reperfusion injury in bilateral ovaries after unilateral ovarian torsion–detorsion in rat. In this study, 24 female Wistar-albino female rats were divided into four groups. Ovarian torsion was produced by applying vascular clamps to right ovaries. In Group I, bilateral oophorectomy was performed. In group II, bilateral oophorectomy was performed after a unilateral torsion period of 4 h. In group III, bilateral ovaries were removed, following unilateral torsion–detorsion periods each lasted for 4 h. Saline was injected i.p. 30 min before detorsion. In group IV, same experimental protocol, which was conducted in group III, was repeated. Iloprost was injected i.p. 30 min before detorsion instead of saline in group IV. Tissue levels of malondialdehyde (MDA) and nitric oxide (NO), which are the indicators for oxidative stress were determined and histopathological evaluation was performed in bilateral ovaries in all groups. The MDA and NO levels for ipsilateral ovaries of four groups were compared and no significant difference was found (p>0.05). The same comparison were done for the contralateral sides and no difference was seen either (p>0.05). In histological examination, iloprost produced improvement in I/R-induced alterations in ipsilateral and contralateral ovaries. In conclusion, these results showed that iloprost has beneficial effect on the histological appearences in both the ipsilateral and contralateral rat ovaries after unilateral torsion–detorsion.     

<Emphasis Type="Italic">Biebersteinia multifida</Emphasis> DC a potential savior against testicular torsion-induced reperfusion injury

The study aimed to investigate the potential therapeutic effect of the methanolic extract of Biebersteinia multifida DC on ischemia–reperfusion injury induced by testicular torsion/detorsion in rats. Forty adult male Sprague-Dawley rats were randomly divided into four groups. Sham operation group, torsion/detorsion group plus saline, and torsion/detorsion groups plus 75 and 150 mg/kg doses of DC extract (administered intraperitoneally 15 min before detorsion). Testicular ischemia was induced via keeping the left testis under 720° counterclockwise torsion for 2 h; afterwards, detorsion was performed. All rats were sacrificed 4 h after detorsion and bilateral testes were removed for histological examinations. The testes in sham operation group had normal structure. Contralateral testicular tissue had mild injury in torsion/detorsion (T/D) group, while it was approximately normal in DC-treated group. In the T/D group, most of the testes demonstrated severe lesions in ipsilateral testes. In contrast, ipsilateral twisted testicular tissue in DC-treated group showed mild to moderate injuries. Similar histopathological results were obtained in both utilized therapeutic doses of DC (75 and 150 mg/kg). B. multifida is a rich source of phenolic antioxidant components that can be potentially used as a free radical scavenger in testicular damages caused by reperfusion injury, although more detailed studies are warranted.     

Protective effect of sildenafil citrate on contralateral testis injury after unilateral testicular torsion/detorsion

OBJECTIVES:

This study was designed to investigate prevention of contralateral testicular injury with sildenafil citrate after unilateral testicular torsion/detorsion.

METHODS:

Thirty‐seven adult male rats were divided into four groups: sham operated (group 1, n  =  7), torsion/detorsion + saline (group 2, n  =  10), torsion/detorsion + 0.7 mg of sildenafil citrate (group 3, n  =  10) and torsion/detorsion + 1.4 mg of sildenafil citrate (group 4, n  =  10). Unilateral testicular torsion was created by rotating the right testis 720° in a clockwise direction for 2 h in other groups, except for group 1, which was served as sham group. After torsion (2 h) and detorsion (2 h) periods, rats were killed.

RESULTS:

The level of reduced glutathion (GSH) (p<0.05) and the activities of catalase (p<0.01) and glutathione peroxidase (p<0.05) in the contralateral testis from group 2 were significantly lower and nitric oxide (NO) (p<0.05) level in the contralateral testis were significantly higher than those of group 1. Administration of low‐dose sildenafil citrate (group 3) prevented the increases in malondialdehyde and NO levels and decreases in glutathione peroxidase activities and GSH values induced by testicular torsion. However, administration of high‐dose sildenafil citrate (group 4) had no effect on these testicular parameters (p>0.05). Histopathological changes were detected in groups 2, 3 and 4.

CONCLUSION:

These results suggest that biochemically and histologically torsion/detorsion injury occurs in the contralateral testis following 2‐h torsion and 2‐h detorsion and that administration of low‐dose sildenafil citrate before detorsion prevents ischemia/reperfusion cellular damage in testicular tissue.     

The effect of spermatic vessel ligation on testicular nitric oxide levels and germ cell-specific apoptosis in rat testis

Management of high testis may vary but the most popular method in surgical treatment is the Fowler-Stephens maneuver. The aim of the present study was to investigate the effects of spermatic vessel ligation on testicular nitric oxide (NO) levels, expression of inducible nitric oxide synthase (iNOS), and endothelial nitric oxide synthase (eNOS) and germ cell-specific apoptosis in both ipsilateral and contralateral testes in rats. Twenty-eight animals were randomly allocated into four groups (n=7 each). The spermatic vessels were ligated as a simulation of the Fowler-Stephens maneuver. The groups of animals were sacrificed at 2 h (group 1), 4 h (group 2) and 24 h (group 3) after ligation, respectively. Sham-operated animals served as controls (group 4). Biochemical assessment of testicular NO levels was performed by the Griess method. iNOS and eNOS expression and apoptosis were studied in ipsilateral and contralateral testes. Testicular NO levels at 24 h after the simulated Fowler-Stephens maneuver were found to be significantly increased in both ipsilateral and contralateral testes when compared with the sham-operated group. eNOS expression was clearly increased in ipsilateral testes, whereas moderate expression was detected in the contralateral seminiferous tubules at 24 h after ligation. Mild focal iNOS immunostaining was also observed in seminiferous tubules of the ipsilateral testis at 24 h after the simulated Fowler-Stephens maneuver. Apoptosis was dramatically increased in ipsilateral testes; however, it was only detected in single cells in the contralateral side at 24 h after ligation. In conclusion, the simulated Fowler-Stephens maneuver induces testicular nitric oxide synthesis and germ cell-specific apoptosis in the ipsilateral testis. These results suggest that high levels of NO induce apoptosis and may impair spermatogenesis thus explaining the unsuccessful outcome of the Fowler-Stephens maneuver.     

Bacterial LPS Mediated Acute Inflammation-induced Spermatogenic Failure in Rats: Role of Stress Response Proteins and Mitochondrial Dysfunction

Bacterial Lipopolysaccharide (LPS) induced inflammation is implicated in the infection associated testicular tissue damage. Earlier, using a LPS induced acute endotoxemic rat model, we have shown the involvement of inflammation-induced oxidative stress in the impaired steroidogenesis and spermatogenesis. In the present study, we report a significant induction (more than 2-fold) of stress response proteins HSP-60, HMGB-1 and 2 in the testes, as early as 6 h after LPS injection with a later decrease. This induction of acute stress is closely followed by a significant reduction (74%) in Bcl2/Bax ratio along with leakage of cytochrome c (3 fold increase, p < 0.05) from mitochondria and increased caspase-3 activity levels (2.9 fold, p < 0.05) at 12 h and 24 h post LPS injection respectively. Further studies on PARP cleavage revealed a pattern similar to necrotic death during early periods (3 h to 24 h) and apoptosis at later periods (24 h to 72 h) after LPS treatment. In conclusion, the present study shows the involvement of stress response proteins and mitochondrial dysfunction in LPS-induced germ cell death in male rats.     

睾丸扭转14例临床诊断与治疗

目的：探讨提高睾丸扭转诊断及治疗水平的临床措施。方法：结合临床症状和体征确诊14例睾丸扭转；13例手术治疗，1例手法复位；结合献对临床资料进行分析。结果：14例中13例行急诊睾丸探查术，1例行手法复位；8例行睾丸切除术，6例保留睾丸，睾丸切除率达57.1％；随访3～12月，复位睾丸及对侧睾丸形态和功能正常。结论：对于睾丸扭转，早期诊断及早期开放手术是提高睾丸保留率的有效方法。     

厄多司坦对大鼠单侧睾丸扭转后双侧睾丸生精功能的保护作用

目的探讨厄多司坦对大鼠睾丸扭转/复位模型的保护作用。方法成年雄性大鼠32只,体重(200±20)g,随机分为4组,每组8只,分别为:假手术组,扭转复位组,扭转复位+生理盐水组,扭转复位+厄多司坦组。按Turner法建立睾丸扭转模型,扭转复位术后24h切取双侧睾丸分别留取组织匀浆和石蜡切片的标本待检测。TUNEL法测定凋亡细胞,化学比色法测定SOD及MDA含量。结果与扭转复位组相比,厄多司坦组生精细胞凋亡明显减少,超氧化物歧化酶活性上升,丙二醛含量下降,其差异有显著性。结论厄多司坦对大鼠单侧睾丸扭转后双侧睾丸生精功能具有保护作用     

Protective effects of Ginkgo biloba (EGb 761) on testicular torsion/detorsion-induced ischemia-reperfusion injury in rats

The aim of this study was to investigate the protective effect of Ginkgo biloba (EGb 761) on testicular torsion/detorsion induced ischemia-reperfusion (I/R) injury. A total of 24 male Wistar albino rats were divided into three groups: control, I/R and I/R treated with EGb 761; each group contains 8 animals. Testicular torsion was created by rotating the left testis 720° in a clockwise direction. The ischemia period was 5 h and orchiectomy was performed after 5 h of detorsion. EGb 761 (50 mg/kg, orally) was administrated only once, 40 min prior to detorsion. To date, no more histopathological changes on testicular torsion/detorsion induced ischemia-reperfusion (I/R) injury in rats by EGb 761 treatment have been reported. Spermatogenesis and mean seminiferous tubule diameter (MSTD) were significantly decreased in I/R groups were compared to the control group. Furthermore, EGb 761 treated animals showed an improved histological appearance in I/R group. Our data indicate a significant reduction in the activity of TUNEL and endothelial nitric oxide synthase (eNOS) in testes tissue of I/R treated with EGb 761 therapy. Electron microscopy of the testes of rats demonstrated that EGb 761 pretreatment was particularly effective in preventing the mitochondrial degeneration, dilatation of SER and enlarged intercellular spaces in both Sertoli and spermatid cells in I/R treated animals. We believe that further preclinical research into the utility of EGb 761 may indicate its usefulness as a potential treatment on testes injury after I/R in rats.     

Exercise-induced muscle damage and the repeated bout effect: evidence for cross transfer

We examined whether a prior bout of eccentric exercise in the elbow flexors provided protection against exercise-induced muscle damage in the contralateral arm. Fifteen males (age 22.7 ± 2.1 years; height 178.6 ± 6.8 cm, mass 75.8 ± 9.3 kg) were randomly assigned to two groups who performed two bouts of 60 eccentric contractions (30°/s) separated by 2 weeks: ipsilateral (n = 7, both bouts performed in the same arm), contralateral (n = 8, one bout performed in each arm). Strength, muscle soreness and resting arm angle (RAA) were measured at baseline and at 1, 24 and 48 h post exercise. Surface electromyography was recorded during both bouts of exercise. The degree of strength loss was attenuated (p < 0.05) in the ipsilateral group after the second bout of eccentric exercise (−22 cf. −3% for bout 1 and 2 at 24 h, respectively). Strength loss following eccentric exercise was also attenuated (p < 0.05) at 24 h in the contralateral group (−30 cf. 13% for bout 1 and 2, respectively). Muscle soreness (≈34 cf 19 mm) and change in RAA (≈5 cf. 3%) were also lower following the second bout of eccentric exercise (p < 0.05), although there was no difference in the overall change in these values between groups. Median frequency (MF) was decreased by 31% between bouts, with no difference between groups. Data support observations that the repeated bout effect transfers to the opposite (untrained) limb. The similar reduction in MF between bouts for the two groups provides evidence for a centrally mediated, neural adaptation.     

Pathological and Immunological Effects of Surgically Induced Varicocele in Juvenile and Adult Rats

ABSTRACT: The presence of a varicocele in adult men has been correlated with infertility. This study documents the effect of an experimentally induced unilateral varicocele in 21-day-old juvenile prepubertal and 51-day-old adult rats (n=10 per group) on subsequent adult testicular function. Varicoceles were induced by partial occlusion of the spermatic vein. There were ten sham-operated and five nonoperated control rats in each age group. The rats were sacrificed 1 month after surgery. Intrascrotal temperatures were elevated in both groups with varicoceles. Histologically, the ipsilateral testes of rats in both age groups demonstrated a decrease in the numbers of functioning seminiferous tubules and germ cells, but the decrease was significantly greater in the juveniles than in the adult rats. No changes were seen in the contralateral testes. Significant titers of cytotoxic sperm antibodies were present in all animals with varicoceles, which is in contrast to controls. The juveniles had significantly lower antibody titers (mean log ± SEM; 3.2 ± 0.09 vs. 8.5 ± 1.1, P < 0.001) than the adults. The induction of a unilateral varicocele damaged spermatogenesis and testicular function to a greater extent in juveniles than in adult rats. This damage may be immune complex-mediated.     

Sodium pyruvate protects against H(2)O(2) mediated apoptosis in human neuroblastoma cell line-SK-N-MC

Free radicals are involved in neuronal damage. The present study was aimed to investigate the protective effect of sodium pyruvate-a free radical scavenger against hydrogen peroxide (H(2)O(2)) induced apoptosis in human neuroblastoma cell line-SK-N-MC. On exposure to H(2)O(2) (0.025 mM) cells exhibited apoptosis within 24 h, demonstrating a high caspase 3 activity by 3 h followed by cleavage of PARP that was maximum at 24 h. A break down in the mitochondrial membrane potential was observed 3 h onwards. Sodium pyruvate protected cells significantly (P<0.05) against apoptosis in a dose dependent manner as assessed for cell viability by dye exclusion method and apoptosis by TUNEL. Sodium pyruvate significantly inhibited caspase 3 activity, cleavage of PARP and breakdown of mitochondrial membrane potential. These data suggest that sodium pyruvate protects neuronal damage caused by H(2)O(2).     

ERAP1 variants are associated with ankylosing spondylitis in East Asian population: a new Chinese case–control study and meta‐analysis of published series

Endoplasmic reticulum aminopeptidase 1 (ERAP1) has been confirmed to be associated with ankylosing spondylitis (AS) in Caucasian. However, whether they are associated with AS in East Asian population remains unidentified. We investigated this relationship by a new Chinese case–control study and a meta‐analysis of published series. 368 cases and 460 controls were recruited in the Chinese case–control study. Genotyping was completed using the chip‐based matrix‐assisted laser desorption ionization time‐of‐flight mass spectrometry. Allelic associations were analysed using contingency tables. In the meta‐analysis, up to 2748 cases and 2774 controls from seven different studies and the new Chinese study were combined using Review Manager software version 5.1.1. Mantel–Haenszel or Inverse Variance test was used to calculate fixed or random‐effects pooled ORs. In the new Chinese study, strong association with AS was observed for marker rs10050860, rs27434 and rs1065407 at P value of <0.001. Moderate association was observed for rs30187 at P value of <0.01, while no association was observed for rs27044 (P = 0.37) and rs2287987 (P = 0.23). The meta‐analysis showed that rs27037 and rs30187 were strongly associated with AS (P < 0.00001). Significant association was also observed for rs27434 (P = 0.001). No association was shown for rs27044 (P = 0.70). We concluded that ERAP1 variants are associated with AS in East Asian population, indicating a common pathogenic mechanism for AS in East Asians and Caucasians.     

死亡底物PARP与细胞凋亡

细胞凋亡是多细胞生物体内的一个重要生命现象.PARP[poly(ADP-ribose)polymerase]的蛋白酶解为半胱氨酸蛋白酶激活的分子事件,是细胞程序死亡的一个早期分子标志.PARP酶作为死亡底物参与凋亡的实施是近年国内外现代生物学研究的热点之一.     

Fast diffusion kurtosis imaging (DKI) with Inherent COrrelation‐based Normalization (ICON) enhances automatic segmentation of heterogeneous diffusion MRI lesion in acute stroke

Diffusion kurtosis imaging (DKI) has been shown to augment diffusion‐weighted imaging (DWI) for the definition of irreversible ischemic injury. However, the complexity of cerebral structure/composition makes the kurtosis map heterogeneous, limiting the specificity of kurtosis hyperintensity to acute ischemia. We propose an Inherent COrrelation‐based Normalization (ICON) analysis to suppress the intrinsic kurtosis heterogeneity for improved characterization of heterogeneous ischemic tissue injury. Fast DKI and relaxation measurements were performed on normal (n = 10) and stroke rats following middle cerebral artery occlusion (MCAO) (n = 20). We evaluated the correlations between mean kurtosis (MK), mean diffusivity (MD) and fractional anisotropy (FA) derived from the fast DKI sequence and relaxation rates R₁ and R₂, and found a highly significant correlation between MK and R₁ (p < 0.001). We showed that ICON analysis suppressed the intrinsic kurtosis heterogeneity in normal cerebral tissue, enabling automated tissue segmentation in an animal stroke model. We found significantly different kurtosis and diffusivity lesion volumes: 147 ± 59 and 180 ± 66 mm³, respectively (p = 0.003, paired t‐test). The ratio of kurtosis to diffusivity lesion volume was 84% ± 19% (p < 0.001, one‐sample t‐test). We found that relaxation‐normalized MK (RNMK), but not MD, values were significantly different between kurtosis and diffusivity lesions (p < 0.001, analysis of variance). Our study showed that fast DKI with ICON analysis provides a promising means of demarcation of heterogeneous DWI stroke lesions.     

Association study of copy number variants in CCL3L1, FCGR3A and FCGR3B genes with risk of ankylosing spondylitis in a West Algerian population

Numerous single nucleotide polymorphisms (SNPs) were explored in the Algerian population to evaluate associated ankylosing spondylitis (AS) genetic risk factors, but no study has identified the impact of copy number variations (CNVs). The aim of the study was to determine whether CNVs of CCL3L1, FCGR3A and FCGR3B genes were also associated with the susceptibility of AS disease in Algerian population. The data set of the current study is composed of 81 patients with AS and 119 healthy controls. All samples were genotyped by digital droplet PCR (ddPCR). Chi‐square test and OR calculation were used to evaluate association between CNVs and AS and the risk associated with copy numbers (CN). In results, FCGR3A CN less than two copies (<2) was significantly increased in spondylitis patients (p = .0001, OR = 7.74 [2.32–25.74]). Additionally, FCGR3A CN < 2 copies association was present only in HLA‐B27 (‐) patients. We have concluded that FCGR3A deletions have an independent effect on AS regarding HLA‐B27 status. This is the first study that investigated the CCL3L1 CNVs in relation to AS risk disease. It reveals that CCL3L1 and FCGR3B CNVs may not be involved in susceptibility to AS risk in the Algerian population.     

The seminiferous epithelial cycle and microanatomy of the koala (Phascolarctos cinereus) and southern hairy‐nosed wombat (Lasiorhinus latifrons) testis

The koala (Phascolarctos cinereus) and southern hairy‐nosed wombat (Lasiorhinus latifrons) are iconic Australian fauna that share a close phylogenetic relationship but there are currently no comparative studies of the seminiferous epithelial cell or testicular microanatomy of either species. Koala and wombat spermatozoa are unusual for marsupials as they possess a curved stream‐lined head and lateral neck insertion that superficially is similar to murid spermatozoa; the koala also contains Sertoli cells with crystalloid inclusions that closely resemble the Charcot–Bottcher crystalloids described in human Sertoli cells. Eighteen sexually mature koalas and four sexually mature southern hairy‐nosed (SHN) wombats were examined to establish base‐line data on quantitative testicular histology. Dynamics of the seminiferous epithelial cycle in the both species consisted of eight stages of cellular association similar to that described in other marsupials. Both species possessed a high proportion of the pre‐meiotic (stages VIII, I – III; koala – 62.2 ± 1.7% and SHN wombat – 66.6 ± 2.4%) when compared with post‐meiotic stages of the seminiferous cycle. The mean diameters of the seminiferous tubules found in the koalas and the SHN wombats were 227.8 ± 6.1 and 243.5 ± 3.9 μm, respectively. There were differences in testicular histology between the species including the koala possessing (i) a greater proportion of Leydig cells, (ii) larger Sertoli cell nuclei, (iii) crystalloids in the Sertoli cell cytoplasm, (iv) a distinctive acrosomal granule during spermiogenesis and (v) a highly eosinophilic acrosome. An understanding of the seminiferous epithelial cycle and microanatomy of testis is fundamental for documenting normal spermatogenesis and testicular architecture; recent evidence of orchitis and epididymitis associated with natural chlamydial infection in the koala suggest that this species might be useful as an experimental model for understanding Chlamydia induced testicular pathology in humans. Comparative spermatogenic data of closely related species can also potentially reflect evolutionary divergence and differences in reproductive strategies.     

Augmenting Regional Cerebral Blood Flow Using External-to-Internal Carotid Artery Flow Diversion Method

The objective of this study was to assess the effect of flow diversion by external carotid artery (ECA) occlusion on ipsilateral regional cerebral blood flow (rCBF). Local cerebral hyperperfusion in rats (n = 12) was induced by ligating the right ECA. Ipsilateral rCBF was determined pre- and post-ligation for 120 min using a laser Doppler flow meter. Sham animals (n = 6) were subjected to the craniotomy without ligation of the right ECA. In a separate series of rats (n = 5), brain tissue oxygen levels (pO₂) in the right and left brain hemispheres were determined before and 90 min after ligation of the right ECA using a tissue oxygenation monitoring unit. We investigated the effect of ECA occlusion hemispheric changes in rCBF in one clinical case as a proof of concept. Ligation of ECA resulted in a statistically significant increase in rCBF on the ipsilateral side compared to the sham-operated rats (p < 0.0001). On average we observed a 34% increase (95% CI: 24–45%) in rCBF in the ipsilateral territory in the treated group compared with sham-operated rats. There was no significant variation in MAP for the treated animals. Vascular permeability and cerebral water content in the right hemisphere after ligation of ECA did not significantly differ from the contralateral hemisphere. Ipsilateral hemisphere tissue pO₂ was significantly higher compared to the contralateral area (p < 0.002) post-ligation or to the ipsilateral area (p < 0.001) prior to ligation. In the clinical case, occlusion of ECA resulted in 3.6% and 12.1% increase in peak value and rise-time of the time-density curves. Flow diversion by temporary occlusion of the ECA can result in increased rCBF and cerebral pO₂ on the ipsilateral side. The strategy may represent a viable option to augment rCBF in focal cerebral ischemia.     

Sodium pyruvate protects against H2O2 mediated apoptosis in human neuroblastoma cell line-SK-N-MC

Free radicals are involved in neuronal damage. The present study was aimed to investigate the protective effect of sodium pyruvate—a free radical scavenger against hydrogen peroxide (H₂O₂) induced apoptosis in human neuroblastoma cell line-SK-N-MC. On exposure to H₂O₂ (0.025 mM) cells exhibited apoptosis within 24 h, demonstrating a high caspase 3 activity by 3 h followed by cleavage of PARP that was maximum at 24 h. A break down in the mitochondrial membrane potential was observed 3 h onwards. Sodium pyruvate protected cells significantly (P<0.05) against apoptosis in a dose dependent manner as assessed for cell viability by dye exclusion method and apoptosis by TUNEL. Sodium pyruvate significantly inhibited caspase 3 activity, cleavage of PARP and breakdown of mitochondrial membrane potential. These data suggest that sodium pyruvate protects neuronal damage caused by H₂O₂.     

Quantitative changes in gene expression of glutamate receptor subunits/subtypes in the vestibular nucleus, inferior olive and flocculus before and following unilateral labyrinthectomy in the rat: real-time quantitative PCR method

Spontaneous recovery from the oculomotor and postural symptoms of unilateral labyrinthectomy (UL) is known as vestibular compensation, which is a useful model for investigation of the mechanisms of lesion-induced CNS plasticity. In the present study, to elucidate the molecular biological basis of vestibular compensation, we investigated changes in the mRNA expression of glutamate receptor subunit/subtypes in the rat central vestibular system, including the vestibular nucleus complex (VNC), inferior olive (IO), and cerebellar flocculus following UL, using a real-time quantitative polymerase chain reaction (PCR) method. In normal control animals, regional differences in the expression of several glutamate receptor subunit/subtypes, e.g., NR1 and NR2A subunits of the N-methyl-D-aspartic acid (NMDA) receptor, GluR2 and KA2 subtypes of non-NMDA receptors, and mGluR1 and mGluR7 metabotropic glutamate receptors, were consistent with previous results from studies using in situ hybridization histochemistry, suggesting that the real-time quantitative PCR method was a reliable procedure for evaluation of changes in mRNA expression. In the vestibular nucleus complex, NR2A, GluR2 and mGluR7 mRNA were ipsilaterally downregulated by 6 h following UL (P<0.05, P<0.05 and P<0.01, respectively). In the inferior olive, no changes in gene expression were observed. In the ipsilateral flocculus, KA2 mRNA expression was increased by 50 h post-UL (P<0.05). However, in the contralateral flocculus, mGluR1 mRNA was downregulated by 6 h post-UL (P<0.005). Both the increase in KA2 mRNA expression in the ipsilateral flocculus and the decrease in mGluR1 mRNA expression in the contralateral flocculus may have had the effect of reducing Purkinje cell inhibition of ipsilateral VNC neurons, thereby contributing to the rebalancing of spontaneous resting activity between the ipsilateral and contralateral VNCs. It is suggested that such changes in the activities of the floccular-VNC pathways may be important to the vestibular compensation process. Electronic Publication