Investigations were carried out into the time-and dose-related changes in acute skin reaction following graded single dose (20, 30 and 40 Gy) of x-ray irradiation in Wistar rats, in order to evaluate the radioprotective effect of Diethon on skin. For the duration of skin response over 1. 5 score in dose of 40 Gy, the Diethone group of 24.7 days was significantly different (p<0.02) from that of control (29.8 days) and vaseline (29.2 days) groups, it was 17.1% diminution of skin response period compared with that of control group. By the averaging daily scores for 10 days during peak skin reaction the mean scores were obtained. Mean score of Diethone group (2.43+/-0.22) was significantly different (p<0.01) from that of control (2.91+/-0.23) and vaseline (2.81+/-0.18) groups of 40 Gy dose. By iso-effect dose obtained at level of 2.5 score the dose reduction factor(DRF) was 1.41 which reduced radiation dose of 41% by radioprotective effect of Diethone. From this experimental data, it may be possible to give higher radiation dose to large and/or radioresistant tumor mass rather than conventional treatment doses for improving therapeutic ratio by using topical application of skin radioprotector.
Animals ; Petrolatum ; Rats* ; Rats, Wistar ; Skin*

No abstract available.
Autoradiography* ; Brain* ; Rats, Wistar* ; Receptors, Muscarinic*

No abstract available.
Colon* ; Colonic Neoplasms* ; Dimenhydrinate* ; Oncogenes* ; Rats, Wistar*

OBJECTIVE: To three-dimensionally elucidate the effects of occlusal hypofunction on the periodontal ligament and alveolar bone proper of rat molars by micro-computed tomography (micro-CT). METHODS: Occlusal function in the molar area was restricted by attaching an anterior bite plate on the maxillary incisors and a metal cap on the mandibular incisors of 5-week-old male Wistar rats for 1 week. The periodontal ligament space and alveolar bone proper around roots of the mandibular first molar were assessed by histology and micro-CT. RESULTS: The periodontal ligament space was narrower and the alveolar bone proper was sparser and less continuous in the hypofunction group than in the control group. Further, both the volume of the periodontal ligament and the volumetric ratio of the alveolar bone proper to the total tissue in the region of interest were significantly lower in the hypofunction group (p < 0.05). CONCLUSIONS: Occlusal hypofunction induces atrophic changes in the periodontal ligament and alveolar bone proper of rat molars.
Animals ; Humans ; Incisor ; Male ; Molar* ; Periodontal Ligament* ; Rats* ; Rats, Wistar

OBJECTIVEQuantitative analysis the regional specificity and time dependence of Ciclosporin (CsP) on gingival tissue modality of rats.

METHODSEighty SPF grade male Wistar rats of 7 weeks old were randomly divided into experimental group and control group, and each group was divided into 4 subgroups according to the duration of treatment (10, 20, 30 and 40 days). The experimental objects were given intragastric administration of fresh milk including CsP, and the control ones were given intragastric administration of fresh milk the same as the experimental objects. After giving perfusion 4% paraform trans-heart to internal fixation, the specimens were get and made bucco-lingual paraffin sections at lower first molar and made HE staining. The area of buccal and lingual gingival epithelial and connective tissue, the length of the longest rete pegs were measured with the image analysis system. Data were analyzed by two-way analysis of variance of factorial design.

RESULTSThe rats of the experimental group took place gingival overgrowth, and the rete pegs of gingival epithelium of attached gingiva approach muco-gingival junction were prolonged. The area of buccal and lingual gingival epithelium and connective tissue, the length of buccal longest rete pegs of the experimental group were significantly higher than that of the control group rats (bucca P < 0.01, lingua 0.01 < P < 0.05). The length of lingual longest rete pegs of the experimental group were no difference than that of the control group rats. The area of buccal and lingual gingival epithelial, connective tissue, the length of longest rete pegs among experimental groups were no difference.

CONCLUSIONCsP may have the regional specificity on the rats' gingival epithelium of buccal attached gingiva approach muco-gingival junction, but the effect of CsP on the rats' gingiva was no time dependence.

Animals ; Electroencephalography ; Heart ; physiopathology ; Immersion ; physiopathology ; Rats ; Rats, Wistar ; Seawater

OBJECTIVETo determine the effects of cigarette smoking on the cyclogeny of spermatogenic cells in rats.

METHODSRat models of passive smoking were established using a self-made smoking device, and then allocated randomly into two passive smoking groups (A and B, n = 10) and two corresponding control groups (C and D, n = 10). Groups A and B were exposed to cigarette smoke for 8 weeks, followed by the sacrifice of the rats in Groups A and C. And the animals in Groups B and D were killed 48 days after the cessation of passive smoking. The spermatogenesis cycle of each group of rats was detected by flow cytometry, the levels of testosterone (T) and luteinizing hormone (LH) measured by radio-immunity method, and the testis histopathology analyzed by HE staining and transmission electron microscopy.

RESULTSCompared with Group C, Group A showed a significant decrease in the number of spermatids, spermatozoa ([18.76 +/- 3.58]%) and primary spermatocytes ([5.71 +/- 1.18]%) (P < 0.01), but an obvious increase in the spermatogonias ([55.98 +/- 5.35]%, P < 0.01), with a markedly decreased proliferation index ( P < 0.01). The rats of Group A also exhibited pycnosis of spermatocytes, nucleus aberration of Leydig cells, expansion and degranulation of the endoplasmic reticulum, decreased Golgi apparatus, increased lysosomes and fat drops of Sertoli cells, as well as a reduction in the thickness of the wall and the layers of seminiferous tubules and the number of spermatogonia. The T and LH levels were significantly lower in Group A than in C (P < 0.01). After the cessation of passive smoking, a remarkable increase was observed in the percentage of spermatozoa and primary spermatocytes and the levels of serum T and LH in Group B, although the latter were still lower than those of Group D.

CONCLUSIONSmoking damages spermatogenic epithelia, Leydig cells and Sertoli cells, reduces the T and LH levels, and block the proliferation of spermatogenetic cells. These changes can be partially reversed after cessation of smoking.

Animals ; Corticosterone ; blood ; Male ; Rats ; Rats, Wistar ; Stress, Physiological

Animals ; Neural Stem Cells ; metabolism ; Rats ; Rats, Wistar ; Semaphorins ; metabolism

PURPOSE: This study was to determine the effect of DHEA administration before, during, and after dexamethasone treatment on body weight and TypeI,II muscle weight of rat receiving dexamethasone treatment. METHOD: Wistar rats were divided into 6 groups: control(C), dexamethasone(D), DHEA administration for 3days after dexamethasone treatment for 7days(7D+3DH), dexamethasone treatment for 7days after DHEA administration for 3days(3DH+7D), DHEA administration during dexamethasone treatment for 4days after dexamethasone treatment for 3days(3D+4DDH), DHEA administration during dexamethasone treatment for 7days(7DDH). Dexamethasone was injected by subcutaneously daily at a dose of 5mg/kg. DHEA was orally administered daily at a dose of 5mg/kg for 7 days. Soleus(TypeI) muscle, and both plantaris and gastro- cnemius(TypeII) muscles were dissected on the 7th day of experiment. RESULT: Body weight of both 3DH+7D group and 3D+4DDH group increased significantly compared with that of 7D group. Body weight of 7D+3DH group decreased significantly compared with that of 7D group, 7DDH group, 3DH+7D group and 3D+4DDH group. Muscle weight of both plantaris and gastro- cnemius tended to decrease compared with that of 7D group. Muscle weight of 7DDH group, 3D+4DDH group and 3DH+7D group increased significantly compared with that of 7D+3DH group. Muscle weight of gastrocnemius of both 3DH+7D group and 3D+4DDH group increased significantly compared with that of 7D group. CONCLUSION: Based on these results, it can be suggested that DHEA administration before and during dexamethasone treatment can increase both body weight and mass of atrophied TypeII muscle induced by dexa- methasone treatment.
Animals ; Body Weight* ; Dehydroepiandrosterone* ; Dexamethasone* ; Muscles* ; Rats* ; Rats, Wistar