Effect of food reductones, 2,5-dimethyl-4-hydroxy-3(2H)-furanone (DMHF) and hydroxyhydroquinone (HHQ), on lipid peroxidation and type IV and I allergy responses of mouse.

The effect of long-term supplementation of food reductones, 2,5-dimethyl-4-hydroxy-3(2H)-furanone (DMHF) (2%, w/w), detected in many foodstuffs including soy sauce, and hydroxyhydroquinone (1,2,4-benzenetriol) (HHQ) (1.2%, w/w), detected in coffee, on mouse lipid peroxidation and type IV and I allergy responses was investigated. The effect of supplementation of these reductones combined with NO(2) inhalation (5-6 ppm) was also investigated. Levels of thiobarbituric acid-reactive substances in lung were remarkably increased, and those in kidney and liver were slightly decreased by supplementation of DMHF or HHQ. The degree of 2,4-dinitrochlorobenzene (DNCB)-sensitized lymph node cell proliferation as assessed by lymph node assay was remarkably enhanced by supplementation of DMHF or HHQ. Both the DNCB-sensitized and the trimellitic anhydride-sensitized increases in IgE levels of mice were enhanced to greater extent by supplementation of DMHF or HHQ. In no cases were additive effects of NO(2) inhalation observable. Allergen-sensitized type IV and I allergy responses of mice may be enhanced by supplementation of food reductones, DMHF or HHQ.

Autoradiographic distribution of mu opioid receptors in the brains of Cu/Zn-superoxide dismutase mice.

Superoxide dismutase (SOD) is an important free radical scavenging enzyme which dismutates the superoxide anion radical. We have evaluated the role of SOD in the regulation of opioid receptors by comparing the concentration of mu opioid receptors labeled with [3H]DAGO (Tyr-D-Ala-Gly-NMe-Phe-Gly-ol) in SOD-transgenic (SOD-Tg) mice and their non-transgenic (Non-Tg) littermates. SOD-Tg mice had higher maximal binding capacity (Bmax) in the shell division of the nucleus accumbens (NAc-shell) in comparison to Non-Tg littermates. There were no differences in Bmax in mu receptors in the core subdivision of the nucleus accumbens (NAc-core). There were no significant differences in receptor affinity (Kd) in either the NAc-shell or in the NAc-core. Moreover, there were no significant differences in either Bmax or Kd in the matrices nor in the patches of any of the striatal subdivisions. However, in a fashion similar to the situation in the NAc-shell, [3H]DAGO binding in the substantia nigra pars compacta (SNpc), the ventral tegmental area (VTA), and the ventral part of the central grey was significantly higher in the SOD-Tg mice in comparison to Non-Tg mice. The present results are discussed in terms of their support for a possible involvement of free radicals in the differences observed in various regions of the SOD-Tg and control mice, which differ in their ability to scavenge the superoxide anion.(ABSTRACT TRUNCATED AT 250 WORDS)

Autoradiographic distribution of [3H]neurotensin receptors in the brains of superoxide dismutase transgenic mice.

Superoxide dismutase (SOD) plays an important role in the protection of cells against the deleterious effects of free radicals by dismutating the toxic superoxide anion radical. Although oxygen-based radicals have been implicated in the process of aging and in neurodegenerative disorders such as Parkinson's disease, the contribution of these free radicals to the pathology of these entities has yet to be clarified. It is also not certain that increased levels of free radical scavenging enzymes would attenuate the molecular and cellular processes that lead to these pathological states. In order to assess the contribution of increased SOD gene dosage to the pathogenesis of Down's syndrome, transgenic mice have been constructed that overexpress the human CuZnSOD. We are also using this model to evaluate the role of free radicals in age-associated changes in brain neurotransmitters and their receptors. In the present study, transgenic mice and their nontransgenic littermates, aged 6 weeks and 21 months, were used in an autoradiographic receptor study of the distribution of brain neurotensin receptors. At 6 weeks of age, there were no significant differences between the two groups of mice in most brain regions. In addition, [3H]NT binding sites showed parallel age-related decreases in the majority of the areas examined in both groups. However, significant age-related decreases in the septum, the diagonal band of Broca, and in some subdivisions of the caudate-putamen were observed only in SOD-Tg mice. In contrast, significant age-related decreases in the core area of the nucleus accumbens and the dorsal aspect of the dentate gyrus of the hippocampus were seen only in non-Tg mice.(ABSTRACT TRUNCATED AT 250 WORDS)

Implantation of genetically modified mesencephalic fetal cells into the rat striatum.

Transplantation of dopamine (DA) cells into the rat model of hemiparkinsonism induced by intranigral 6-hydroxydopamine (6-OHDA) injections has so far focused mainly on DA replacement via a pump-like mechanism. In the present study, we employed a model of hemiparkinsonism that uses an intrastriatal approach to lesioning the nigrostriatal DA pathway to assess the possibility of using cell transplantation to cause regeneration of that system. Toward that end, we transplanted two types of cells on the side of the 6-OHDA-induced lesions: 1) nonmodified fetal mesencephalic cells and 2) fetal mesencephalic cells that have been infected with a retrovirus vector containing a PKC beta 1 cDNA. Both types of cells cause behavioral improvement although the changes were more prominent and occurred earlier in the PKC-modified groups. Tyrosine hydroxylase (TH) immunocytochemistry revealed significantly cell survival in both groups of animals; in situ hybridization studies confirmed the continuous expression of TH mRNA in both groups. Interestingly, long TH-positive axons were observed only in the striata of animals implanted with PKC-modified cells. More importantly, surviving endogenous nigral TH-positive cell bodies were found only on the lesioned side in the latter group. The observations in these animals were associated with significantly smaller decreases in [3H]mazindol-labeled DA uptake sites in both the striata and substantia nigra pars compacta on the side ipsilateral to the 6-OHDA-induced lesions. Furthermore, immunohistochemical studies revealed increased gliosis in the striata of animals grafted with the PKC-modified cells. When taken together, these results indicate that transplantation of normal fetal mesencephalic cells can cause behavioral improvement by providing DA to the host striata whereas PKC-modified cells can, in addition, prevent the progressive degeneration of or cause regeneration of the dying nigrostriatal DA neurons in this model of hemiparkinsonism. These results are discussed in terms of their support for a role for second messenger systems and glial cells, as well as extracellular matrix molecules in the regeneration of the CNS.

Marked increase in cerebrospinal fluid ubiquitin in Creutzfeldt-Jakob disease.

We have established the radioimmunoassay for ubiquitin in the cerebrospinal fluid (CSF) and measured the ubiquitin concentration in CSF from 4 cases of neuropathologically verified Creutzfeldt-Jakob disease (CJD), 10 cases of multi-infarct dementia (MID), 7 cases of senile dementia of Alzheimer type (SDAT), and 18 controls. The normal values were determined to range from 7.3 to 21.0 ng/ml, 14.3 +/- 1.1 ng/ml in the mean +/- S.E.M. The CSF ubiquitin levels in the cases of MID and SDAT were 16.6 +/- 6.4 ng/ml and 21.3 +/- 6.1 ng/ml, respectively. In the cases of CJD, the CSF ubiquitin was markedly increased at the early and middle stages of the disease (230.6 ng/ml in Case 1, 107.6 ng/ml in Case 2, 212.5 ng/ml in Case 3, and 377.0 ng/ml in Case 4) and these gradually decreased as the disease progressed. The measurement of CSF ubiquitin seems useful to make an early diagnosis of CJD.

Bilateral modulation of [3H]neurotensin binding by unilateral intrastriatal 6-hydroxydopamine injections: evidence from a receptor autoradiographic study.

The present study was carried out in order to re-evaluate the issue of the localization of neurotensin receptors in the caudate-putamen and in the nucleus accumbens of rat. Intrastriatal injections of 6-hydroxydopamine which cause almost complete destruction of the mesostriatal dopaminergic pathway also caused a marked loss of neurotensin receptors in the caudate-putamen (CPu), the nucleus accumbens (NAc) and in the olfactory tubercle (OT). These decreases corresponded to a mean loss of 98, 93 and 41% in the CPu, the NAc, and the OT, respectively. There were corresponding decreases in the substantia nigra pars compacta (SNpc) (-94%) and pars reticulata (SNpr) (-97%), and in the ventral tegmental area (-78%). Moreover, there were also decreases in neurotensin receptors on the contralateral side of the intrastriatal injections which occurred in the CPu but not in the NAc nor in the OT. These results indicate that almost all NT receptors measured within the CPu and the NAc are located on the terminals of dopaminergic neurons within those structures. The bilaterality of the changes which occur in the CPu provide further support for the notion of the interdependence of the two nigrostriatal dopaminergic projections and the peptidergic systems with which they interact.

Receptor autoradiography of mu and delta opioid peptide receptors in spontaneously hypertensive rats.

The receptor autoradiographic distribution of opioid peptide receptors in spontaneously hypertensive rats (SHR) was compared to that of Sprague-Dawley (SD) rats, using the highly selective mu and delta opioid receptor ligands, [3H]DAGO (Tyr-D-Ala-Gly-NMe-Phe-Gly-ol) and [3H]DPDPE ([D-Pen2,D-Pen5]enkephalin), respectively. Although the distribution of these binding sites was similar in both strains, SHR showed significantly higher binding densities of mu receptors in 16 of 27 areas examined. These included the patch and matrix components of the caudate-putamen (CPu), olfactory tubercle, endopiriform nucleus, anterior cingulate cortex, ventral tegmental area lateroposteral thalamic nucleus and the ventral part of the dentate gyrus. In contrast, SHR had lower [3H]DAGO binding sites in the CA1 of the hippocampus. Conversely, SHR showed higher binding densities of delta receptors in 7 of 20 areas examined, including the CPu, CA2 and CA3 areas of the hippocampus and the central grey. High-to-low lateromedial gradients of striatal delta receptors were observed in both strains. Because opioid peptides are known to participate in locomotive behavior in rodents and in the control of blood pressure, the present results support a role of opioid peptidergic systems in the manifestation of hyperactivity and hypertension observed in SHR.

Autoradiography of dopamine receptors and dopamine uptake sites in the spontaneously hypertensive rat.

We examined the status of dopamine (DA) D1 and D2 receptors by using [3H]SCH 23390 and [3H]spiperone binding, respectively, and DA uptake sites by using [3H]mazindol binding in spontaneously hypertensive rats (SHR) and Sprague-Dawley (SD) rats. SHR showed significantly higher [3H]SCH 23390 and [3H]spiperone binding in the caudate-putamen (CPu), the nucleus accumbens (NAc) and the olfactory tubercle (OT) in comparison to the SD rats. There were no significant differences in [3H]mazindol-labeled DA uptake sites between the two strains. Unilateral 6-hydroxydopamine (6-OHDA) injection into the striatum resulted in more than 90% depletion of DA uptake sites in the CPu in both strains. 6-OHDA-induced DA depletion was associated with significant increases in striatal [3H]spiperone binding which were of similar magnitude in the SD rats (+64.1%) and SHR (+51.3%). There were only small decreases (-5.4%) in D1 receptor binding in the dorsolateral aspect of the CPu in the SHR, whereas there were no changes in striatal D1 receptors in the SD rats. These results indicate that, although the SHR have higher concentrations of both D1 and D2 receptors in the basal ganglia, these receptors are regulated in a fashion similar to DA receptors in SD rats after 6-OHDA-induced striatal DA depletion.

Tonotopic representation and space map in the non-primary auditory cortex of the mustached bat.

As auditory system has no sensory epithelium into which auditory space are projected, we studied the physiological map of the auditory space in the non-primary auditory cortex of the mustached bat by using the echo of their orientation sound. Ten bats were used as experimental subjects. Tungsten wire electrodes were inserted obliquely in the dorsomedial (DM) and ventroposterior (VP) areas of the non-primary auditory cortex. When single neuron was isolated, best frequency (BF), best azymuth (BAZ) and best elevation (BEL) were measured and were plotted on a schematic figure. To mimic its biosonar, one loudspeaker, delivering synthesized orientation sounds, was placed in front of the animal, and another loudspeaker delivering synthesized echo was mounted on a movable hoop. Tonotopic representation was observed but complicated in both areas, and those areas could be divided into several subdivisions consisting of the neuron groups characterized by three frequency bands. The neurons were thought to be related to the processing of biosonar informations from the facts that their BFs agreed with the scope of the FM sweep of each echo harmonics. The magnitude of the response showed rapid increase at their BAZ or BEL, so that the neurons seemed to tune to a certain direction in the auditory space. Especially in the DM area, neurons assumed a systematic arrangement of their BAZs on the cerebral surface and showed some tendency of a systematic arrangement of their BELs. The DM area was thought to have a kind of neural map of the auditory space.