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T Serikawa

Publications and source records attributed to T Serikawa.

At least 109 records · Page 6Linked to original sources
PubMed1994

Genetic profiles of 12 inbred rat strains for 46 microsatellite loci selected as genetic monitoring markers.

Genetic profiles for 46 microsatellite loci of 12 inbred strains of rats, including 2 congenic strains and a coisogenic strain, have been demonstrated. Rates of loci with different alleles between 2 inbred strains, which are not closely related to each other in origin, were from 71.7% between ACI/N and IS/Kyo strains to 41.3% between F344/N and TM/Kyo. On the other hand, the rates were 0% in both of 2 sets of congenic strains; between F344/N and F344/N-rnu, or between BN/fMaiKyo and BN.IS. When WTC/Kyo and the coisogenic strain TRM/Kyo (WTC/Kyo-tm) were compared for 115 microsatellite loci, no loci with different alleles between the strains were found. The 46 loci should be useful as genetic monitoring markers, since all of the primer pairs generate distinct PCR-products at a fixed annealing temperature of 55 degrees C.

Alleles↗
PubMed1994

Improvement of poor operant performance by continual intake of phenobarbital in spontaneously epileptic rats.

Spontaneously epileptic rats (SER) are a double mutant (zi/zi, tm/tm) obtained by mating the tremor rats with another tremulous mutant, zitter rats, and spontaneously exhibit absence-like seizures, tonic convulsions and wild jumping or running episodes. In addition, SER exhibit retardation in learning ability under differential reinforcement at a low rate (DRL)-5 sec schedule of food reinforcement in operant behavior at 14 to 15 weeks of age. We examined the long-term effects of phenobarbital (PB) on total bar presses, reinforcements and inter-response time distribution to assess whether the poorness of learning ability in SER can be ascribed to frequent occurrence of seizures. Food pellets containing 0.1% PB were given ad libitum to male SER from 7 weeks, and operant behavior was examined at 13 to 14 weeks of age. Tonic seizures and wild jumping or running episode were inhibited effectively and poor operant performance was significantly improved by continual intake of PB in SER.

Administration, Oral↗
PubMed1993

Chromosomal localization of angiotensin II type 1 receptor isoforms in the rat.

The cDNA sequences of two different isoforms of the rat angiotensin II type 1 receptors, AT1A and AT1B, have been reported. A single set of polymerase chain reaction primers was used to amplify sequence from both AT1A and AT1B from rat genomic DNA. Genomic DNA from a panel of rat x mouse somatic hybrid cell lines which had been characterized as to the rat chromosomal content was then amplified with these primers. The amplified products from rat AT1A and AT1B were distinguished from each other and those of the mouse by the use of differential restriction patterns. Using this method, AT1A was localized to rat chromosome 17 and AT1B to rat chromosome 2.

Angiotensin II↗
PubMed1993

A neuropeptide Y locus on chromosome 4 cosegregates with blood pressure in the spontaneously hypertensive rat.

Recent advances in molecular biology have allowed the study of the candidate genes for essential hypertension. To identify the genes responsible for basal blood pressure in the spontaneously hypertensive rat strain, the rat model of genetic hypertension, we performed a cosegregation analysis between the genotype and blood pressure in a set of male F2 progeny obtained from SHR and Wistar-Kyoto rats, a reference normotensive strain. Our investigation revealed that a locus on the chromosome 4 cosegregates with the blood pressure in SHR, especially at neuropeptide Y locus. The degree of cosegregation with all values of blood pressure without sodium loading was moderate but consistent. We propose that neuropeptide Y locus on chromosome 4 is a new candidate for the hypertensive effect in original SHR.

Animals↗
PubMed1993

Local cerebral glucose utilization in the interictal state of the spontaneously epileptic rat (SER).

Local cerebral glucose utilization (LCGU) in spontaneously epileptic rats (SER) and in their parent strains, zitter (ZI) and Kyoto-Wistar (KW) rats was studied by autoradiography with [14C]2-deoxyglucose. Compared to the LCGU in age-matched KW rats, LCGU in 8-week-old SERs, which had not yet exhibited epileptic seizures, was low in all brain regions examined, and there were no significant differences among the regions. Moreover, there were no differences in LCGU among all regions examined in both SERs and in ZI rats. By contrast, the interictal LCGU in 13-week-old SERs, which did exhibit epileptic seizures, was generally lower than in the other two strains, particularly in the hippocampus and amygdala. These findings suggest that the epileptogenic focus in SERs may lie in the hippocampus and amygdala.

Animals↗
PubMed1993

Abnormal excitability of hippocampal CA3 pyramidal neurons of spontaneously epileptic rats (SER), a double mutant.

The spontaneously epileptic rat (SER:zi/zi, tm/tm), a double mutant, shows both tonic convulsions and absence-like seizures characterized by low-voltage fast waves and by 5-7 Hz spike and wave-like complexes in the cerebral cortical and hippocampal EEG, respectively. Characteristics of hippocampal CA3 pyramidal neurons were examined to determine whether these neurons are abnormally excitable. When a single stimulus was given to the mossy fiber, there was repetitive firing and a depolarization shift in neurons of mature SER (over 12 weeks old), in which epileptic seizures had fully developed. However, in young SER (7-8 weeks old) and littermates (zi/zi, tm/+), which did not show any seizures, only a single spike was elicited with each single stimulation of the mossy fiber. Intracellular recording showed that the resting membrane potential was not significantly different among young and mature SER and littermates, but a long-lasting (100-200 ms) depolarizing shift accompanied by repetitive firing was observed following a single stimulation of the mossy fiber in half of the CA3 neurons of mature SER. Furthermore, the input impedance of the CA3 neurons in mature SER was lower than that in young SER and in littermates. These results indicate that SER hippocampal CA3 neurons become abnormally excitable in conjunction with the development of epileptic seizures.

Animals↗
PubMed1993

DNA segments mapped by reciprocal use of microsatellite primers between mouse and rat.

Rat microsatellite primers were used for detection of homologous DNA segments in the mouse species (Mus laboratorius, Mus musculus musculus, and Mus spretus). Twenty five (16.3%) of 153 rat primer pairs amplified specific DNA segments, when genomic DNA of mice was used as a template in the polymerase chain reaction (PCR). Size variation among inbred strains of mice was found for 13 DNA segments (8.5%). Eight out of the 13 polymorphic DNA segments were mapped to a particular chromosome with two sets of recombinant inbred strains, AKXL or BXD. Similarly, mouse microsatellite primers were used for detection of homologous DNA segments in rats (Rattus norvegicus). Twenty (12.0%) of 166 primer pairs amplified specific DNA segments from rat genome. Size variation among inbred strains of rats was found for seven DNA segments (4.2%). Eleven of these 20 DNA segments were mapped with a rat x mouse somatic cell hybrid clone panel and/or linkage analysis by use of backcross progeny. Our results suggest that the mapped DNA segments are really homologs between mouse and rat. These polymorphic DNA segments are useful genetic markers.

Animals↗
PubMed1993

GABA-gated chloride ion influx in brains of tremor rats.

We measured the GABA-gated chloride ion influx and GABA concentrations in the cerebral cortex and the hippocampus of young (5 weeks old) and older (15 weeks old) tremor rats. GABA-gated chloride ion influx in these tremor rats was significantly greater than in the controls of both the 5 week- and 15 week-old groups. GABA concentrations in the cerebral cortex and hippocampus of the tremor rats increased compared with controls of 5 weeks and decreased compared with controls of 15 weeks. These findings suggest that the GABAergic presynaptic neurons in the cortex and hippocampus of the tremor rat are disturbed with aging. This change may be related to the appearance of absence-like seizures in the rats. The increased GABA-gated chloride ion influx in tremor rats may be a compensatory mechanism against the genetically-determined seizure susceptibility of these rats. Furthermore, the increased GABA levels and GABA-gated chloride ion influx found in 5 week-old tremor rats may be related to the tremor movements.

Animals↗
PubMed1993

Changes of NMDA receptor binding in spontaneously epileptic rat and parent strains.

We measured the binding of [3H]3-[(+/-)2-carboxypiperazin-4-yl] propyl-1-phosphonic acid ([3H]CPP), a competitive ligand for N-methyl-D-aspartate (NMDA) receptors, in double mutant spontaneously epileptic rats (SER: zi/zi, tm/tm) and their parent strains, zitter rats and tremor rats, and WTC rats (control rats from tremor rats derived from Kyoto:Wistar rats) before and after the onset of seizures in tremor rats and SER. Significantly lower [3H]CPP binding receptor density (Bmax) was found in the cortex of SER and zitter rats at 12-15 weeks of age than in that of WTC rats and tremor rats, and at 4 weeks of age the Bmax in zitter rats was lower than that in the other strains. The reduction of Bmax in SER at 12-15 weeks of age may reflect a down regulation of NMDA receptors due to repetitive tonic seizures in SER.

Animals↗
PubMed1993

Regional mapping of the Rowett nude gene (RONU) to rat chromosome 10q24-->q32 by localizing linked SYB2 and GH loci.

The Rowett nude gene (RONU) has been mapped on rat chromosome (Chr) 10 by linkage analysis using (ACI x F344/N-RONU/RONU)F1 x F344/N-RONU/RONU backcross progeny. The gene order on the chromosome was RR92- (16.1 cM) - RR24 - (17.9 cM) - MYHSE (myosin heavy chain, embryonic) - (1.0 cM) - SYB2 (synaptobrevin 2) - (1.0 cM) - SHBG (sex hormone-binding globulin) - (4.0 cM) - RONU (Rowett nude) - (29.0 cM) - AEP (anion exchange protein), PPY (pancreatic polypeptide) - (3.0 cM) - ACE (angiotensin I converting enzyme), GH (growth hormone). The RONU locus was localized to 10q24-->q32 by fluorescence in situ hybridization of the closely linked SYB2 and loosely linked GH loci on the opposite side. Conserved linkage of homologous loci mapped to rat Chr 10 and mouse Chr 11 supports the hypothesis that the RONU locus is a rat homolog of the mouse nu locus.

Animals↗
PubMed1993

Genetic polymorphisms of salivary proteins in the rat.

Two genetic polymorphisms of salivary proteins were found by polyacrylamide gel electrophoresis among inbred strains of rats. Both proteins (RSP-1 and RSP-2) were inherited as a single autosomal trait. The loci were designated as Rsp-1 (rat salivary protein-1) and Rsp-2. Rsp-1 had two codominant alleles (Rsp-1a, Rsp-1b), and Rsp-2 had two alleles (Rsp-2a, and Rsp-2b); Rsp-2a was dominant over Rsp-2b. The Rsp-1 locus is not linked with the linkage groups (LGs) I, II, IV, V and the LGs containing Acp-2 and Pg-1. The Rsp-2 is not linked with the LGs I, II, V, X and the LGs containing Amy-1, Es-6 and Pg-1.

Alleles↗
PubMed1993

Retinal dopamine and its metabolite contents in zitter rats and spontaneously epileptic rats.

In order to investigate the relationship between visual dysfunction and retinal DA metabolism in zitter rats and spontaneously epileptic rats (SER), we measured the amounts of retinal dopamine (DA) and its metabolites, 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillate (HVA). DA, DOPAC and HVA contents were markedly decreased in zitter rats as compared with the controls, Kyo:Wistar or Sprague-Dawley rats. In contrast, in SER, retinal DA and its metabolite contents were not significantly different from those of Kyo:Wistar rats. SER showed higher levels of DA and its metabolites in comparison with Sprague-Dawley rats. Thus, it is suggested that the debilitation of retinal DA synthesis is at least partly related to the visual dysfunction observed in zitter rats, but not that of SER.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1992

Antiepileptic effects of CNK-602A, a novel thyrotropin-releasing hormone analog, on absence-like and tonic seizures of spontaneously epileptic rats.

The effects of CNK-602A (N-[(6-methyl-5-oxo-3-thiomorpholinyl) carbonyl]-L-histidyl-L-prolinamide), a novel thyrotropin-releasing hormone related analog, were investigated on absence-like seizure and tonic convulsion in the spontaneously epileptic rat (SER), which is a genetically defined double-mutant. When CNK-602A of 0.2-1 mg/kg was given intravenously to the animal, there were no changes in the background EEG except for an increase in low-voltage fast waves concomitant with behavioral alertness. However, CNK-602A suppressed absence-like seizure and tonic convulsion in a dose-dependent manner for over 1 h. These antiepileptic effects of CNK-602A on both seizures were antagonized by pretreatment with haloperidol (1 mg/kg, i.p.). It was found, using a brain in vivo microdialysis method, that CNK-602A at a dose of 1 mg/kg, which inhibits the seizures, increased the release of dopamine in the caudate nucleus. These results suggest that CNK-602A inhibits the seizures of SER in a similar manner to thyrotropin-releasing hormone (TRH), probably by increasing the release of dopamine in the central nervous system. In addition, the antiepileptic effects of CNK-602A were more potent and lasted longer than those of TRH.

Animals↗
PubMed1992

Hypotensive effect associated with a phospholipase C-delta 1 gene mutation in the spontaneously hypertensive rat.

To identify the genes responsible for blood pressure in the spontaneously hypertensive rat strain, we performed a cosegregation analysis between the genotype and blood pressure in a set of male F2 rats obtained by crossmating SHR with Wistar-Kyoto rats, a parental normotensive strain. Our investigation revealed that the phospholipase C-delta 1 polymorphism, which resulted in missense mutation, cosegregates with the lower blood pressure in SHR, and that PLC-delta 1 gene is located on chromosome 8. On the other hand, we found the lack of cosegregation between blood pressure and the nerve growth factor receptor gene, which is linked to a hypertensinogenic gene locus (denoted as BP/SP-1) on chromosome 10. We propose that PLC-delta 1 gene itself of closely linked gene on chromosome 8 is a new candidate with the hypotensive effect, and that BP-SP1 locus does not directly contribute to blood pressure elevation in original SHR.

Animals↗
PubMed1992

Polymorphisms revealed by PCR with single, short-sized, arbitrary primers are reliable markers for mouse and rat gene mapping.

Ten single, arbitrarily designed oligodeoxynucleotide primers, with 50-70% (G+C) content, were used to amplify by polymerase chain reaction (PCR) sequences with DNA templates from several mouse species (Mus spretus, Mus musculus musculus, and Mus musculus domesticus), as well as DNA from the laboratory rat (Rattus norvegicus). Eight of these ten primers, used either individually or associated in pairs, generated a total of 13 polymorphic products which were used as genetic markers. All of these polymorphic sequences but one were mapped to a particular mouse chromosome, by use of DNA panels prepared either from interspecific backcross progeny of the type (C57BL/6 x Mus spretus)F1 x C57BL/6 or DNA samples prepared from two sets of recombinant inbred (RI) strains (AKXL and BXD). Six rat-specific DNA segments were also assigned to a particular chromosome with DNA panels prepared from 18 rat/mouse somatic cell hybrids segregating rat chromosomes. From these experiments we conclude that, under precisely standardized PCR conditions, the DNA molecules amplified with these arbitrarily designed primers are useful and reliable markers for genetic mapping in both mouse and rat.

Animals↗
PubMed1992

A single serine:pyruvate aminotransferase gene on rat chromosome 9q34-q36.

It was found in our previous study (Oda et al., 1990. J. Biol. Chem. 265: 7513-7519) that in the rat two mRNAs encoding mitochondrial and peroxisomal serine:pyruvate aminotransferase (SPT/AGT) are formed from a single SPT/AGT gene through alternative transcription initiation in exon 1. In an attempt to analyze the mechanisms underlying this unique phenomenon, we have isolated genomic clones harboring the entire rat SPT/AGT gene. In the present study, the location of the rat SPT/AGT gene was determined to be in the q34-q36 region of chromosome 9 by fluorescence in situ hybridization. Southern blot analysis of rat genomic DNA revealed an allelic BamHI restriction fragment length polymorphism among three different inbred rat strains. These results indicated that a single copy SPT/AGT gene is located on chromosome 9q34-q36 in the rat genome. This locus has been assigned the gene symbol Spat.

Animals↗