Rattus Norvegicus Var Research Articles

The Importance of Coprophagy and Transplacental Transmission in Spread of Sarcocystis Rodentifelis in Rats

Using the experimental model ‘Sarcocystis rodentifelis – laboratory rat (Rattus norvegicus var. alba)., three experiments with 340 ‘Wistar’ rats were carried out. The aim of the study was: (1) to investigate a possibility of the faecal-oral transmission of S. rodentifelis in rats; (2) to find oocysts or sporocysts of that parasite in faeces of sarcocyst-infected rats; (3) to evaluate the role of transplacental transmission in the distribution of S. rodentifelis. It was established that intestines of rats infected with S. rodentifelis sarcocysts are infective to intact rats from days 4–8 to 54–70 (throughout the experiment) and faeces – from days 6 to 80 after the sarcocysts are eaten. In faeces of sarcocyst-infected rats, several sporocysts and one oocyst were found. In rodent faeces, sarcosporidians of those stages were detected for the first time. Sarcocysts were not found in muscles of 83 rattling born by eight females infected with oocysts/sporocysts of S. rodentifelis. A conclusion was drawn that fae...

Effects of Spiramycin on Chromosome Aberration and Micronucleus Formation in Rat Bone Marrow Cells.

The aim of this study was to investigate potential clastogenicity/genotoxicity of the antibiotic spiramycin in bone marrow cells of rats (Rattus norvegicus var. albinos). In the study, spiramycin induced the chromosome aberations at all concentrations (100, 200, 400 mg/kg bwt. (body weight) /d oral) in 21 d when compared with the solvent control group (sunflower seed oil). In addition, spiramycin induced the chromosomal aberration (CA) at only 200 mg/kg bwt. intraperitoneal (i.p.) in 12 h and 100 and 400 mg/kg bwt. i.p. in 24 h when compared with the control group. Spiramycin induced the micronucleated polichromatic erythrocytes (MNPCE) only at 200 mg/kg bwt. i.p. in 12 h and 100 mg/kg bwt. i.p. in 24 h. However, there was no significant difference in the formation of micronuclei at the other concentrations.

In Vivo Genotoxic Effects of Spiramycin in Rat Bone Marrow Cells.

The aim of this study was to investigate the genotoxic effects of spiramycin which is an effective ingredient of the antibiotic rovamycine in bone marrow cells of rats (Rattus norvegicus var. albinos). The rats were treated with 100, 200, 400 mg/kg bwt/day of spiramycin. Animals were treated with the above concentrations for 7 days and the bone marrow preparations were prepared after 6 and 12 h from the last administration. In 100 mg/kg bwt/day, spiramycin increased the percentages of the abnormal cells and the chromosomal aberration per cell (CA/cell) in the bone marrow cells of rats that were sacrificed after 6 h from the last administration. It could not induce the abnormalities however at the other concentrations (200 and 400 mg/kg bwt/day). The mitotic index (MI) was not decreased by any treatment of spiramycin. Spiramycin did not increase neither the percentage of abnormal cells nor the CA/cell in bone marrow cells of rats which sacrificed after 12 h from the last administration, whereas it generally decreased the MI in this treatment. Spiramycin did not affect the formation of chromosomal gaps.

Transport of proteins into mitochondria: A high conservation of precursor uptake and processing system

1. 1. Ornithine transcarbamylase (EC 2.1.3.3) of rat ( Rattus norvegicus var. albus) liver, a urea cycle enzyme, is synthesized extramitochondrially as a larger precursor which is transported posttranslationally into mitochondria and processed to the mature enzyme. 2. 2. The precursor synthesized in vitro was taken up and processed to the mature enzyme by isolated pigeon ( Columba livia var. domestica) liver and frog ( Rana catesbeiana) liver mitochondria. Carp ( Cyprinus carpio) liver mitochondria could also process the precursor. 3. 3. These results indicate that the mitochondrial transport and processing activities are conserved between mammalian and bird, amphibian or fish systems. 4. 4. However, attempts to demonstrate the precursor uptake and processing by Saccharomyces cerevisiae mitochondria were unsuccessful.

Some comparative aspects of renal adaptation to unilateral nephrectomy in white rats and kangaroo rats

1. 1. White rats ( Rattus norvegicus var. alb.) and kangaroo rats ( Dipodomys hermanii) were unilaterally nephrectomized and changes in renal weight, water consumption, renal mitotic activity, urine sodium, urine osmolality and urine volume were determined daily for up to a month following surgery. 2. 2. Unilateral nephrectomy in white rats resulted in significant increases in the wet weight of surviving kidney tissue, decreased water consumption, decreased urine osmolality and decreased urine sodium concentration when averaged over a 30 day post-operative period. 3. 3. Unilaterally nephrectomized kangaroo rats showed significant increases in the wet weight of the surviving kidney along with decreased uring volume, increased water consumption and decreased daily sodium excretion over a 30 day post-operative period. 4. 4. Both groups of animals showed short-term increases in cortical renal mitotic activity and cell size which were in agreement with significant increases in the wet weight of the surviving kidney.

新クマリン系殺鼠剤に関する研究

According to the previous findings that coumarin-3-carboxylic acid and 6-coumarinylamine coumarin-3-carboxylate have a strong hypothermal action and toxic action to rats, a study was made in an effort to apply these compounds as rat poisons. These compounds and in addition, thallium coumarin-3-carboxylate have superior toxic effect on rat (Rattus norvegicus var. albinus) and mouse (Mus musclus), and have a little toxicity for domestic animals such as dogs and cats. Thus, there may be a possibility of application of these coumarins as rat poisons for practical use.

鼠の忌避剤について

To make investigations on the repellents against rats (Rattus norvegicus var. albinus), we tried to experimental repellents of rats with several chemicals : 1. γ-BHC (crystal)-Ortho-DichloroBenzene mixed solvent has made the most effective to their repellents in the case of using trial chemicals this time (after solving γ-BHC of 20g. into acetone of 70g., 20cc. ortho-dichlorobenzene together with 1cc. eugenol added to the above and it was made of 100cc. in total quantities). 2. Mixed chemicals composed of 1.8l. creosote, 400g. naphthaline and 180cc. gasoline, being used for hare's repellents in general are shown effectivelly against to the most.