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1.
Synopsis Adult clearnose skates, Raja eglanteria, were captured during the winters of 1981 and 1983, and observed to mate in captivity. Mating and egg depositions take place on the central west coast of Florida from December through mid-May. During copulation the male holds the trailing edge of the female's right or left pectoral fin firmly in his mouth, swings his tail beneath hers and inserts one clasper into the distal end of her reproductive tract. Copulation may last one to four hours during which time sperm pass from the urogenital papilla of the male along the clasper groove to the female. Sperm move cranially to the upper portion of the shell gland where they are stored and remain viable for at least three months. The ovum is fertilized in the shell gland. The egg case bears a prominent projection or horn at each corner. The two posterior ones are shorter and bear tendrils which are covered with a sticky substance that insures attachment to the substrate when the egg is deposited. Fertilized eggs are laid in pairs at intervals ranging from 1 to 13 days (mean of 4.5 ± 2.2 days). As development proceeds within the egg case a plugged slit on the lateral side of each horn opens and permits seawater to wash the developing embryo. Incubation periods for eggs maintained between 20–22°C decrease in duration throughout the egg laying season, ranging from 94 days initially to 77 days for eggs laid later in the spring. At hatching, the anterior end of the egg case ruptures, and the skate emerges abruptly with its pectoral fins rolled dorsally.  相似文献   

2.
Flow cytometric DNA analysis was used to determine the DNA content of red blood cells from Ginglymostoma cirratum (Bonaterre) and Raja eglanteria (Bosc). The DNA content/nucleus was calculated to be 7.6 and 7.1 pg/nucleus, respectively. Peripheral red blood cells obtained both from G. cirratum and from R. eglanteria were demonstrated to be actively cell cycling. Percentages of red blood cells in the phases of the cell cycle ( G 0/ G 1, S , and G 2/ M ) not only varied considerably between different fishes but also were quite variable in weekly samples obtained from individual animals.  相似文献   

3.
Morphogenesis of the clearnose skate, Raja eglanteria, was not significantly inhibited as a result of 7 days of exposure to 1-2 mM selenate in the sea water during Days 59-69 of embryonic development (hatching would normally have occurred at 82 +/- 4 days of incubation). Although corneal transparency appeared normal in the eye, preliminary measurements of the thickness of Bowman's layer of the cornea suggested that it was significantly thinner in the corneas of embryos exposed to 1-2 mM selenate. Selenate is an ion reported to inhibit sulfation of glycosaminoglycans in connective tissue.  相似文献   

4.
Effects of insulin-like growth factor-I (IGF-I), corticosterone, and triiodothyronine (T(3)) on in vitro growth of vertebral cartilage of the clearnose skate, Raja eglanteria, were investigated. Uptake of [(35)S]sulfate in cultured vertebrae was used to characterize glycosaminoglycan (GAG) synthesis and cartilage growth. IGF-I significantly enhanced cartilage growth when concentrations of 1.28 and 12.8 nM were present in the culture system. Corticosterone significantly inhibited vertebral GAG synthesis at concentrations of 1, 10, and 100 nM. This effect was markedly pronounced in cartilage exposed to 1 and 10 nM corticosterone, in which GAG synthesis was virtually ceased. In contrast, T(3) (0.75, 7.5, and 75.0 nM) had no significant effect on sulfate uptake. These data suggest that IGF-I and corticosteroids may play important roles in regulating skeletal growth of elasmobranchs, as they appear to do in other vertebrates. While T(3) does not appear to exert an immediate, direct effect on vertebral growth, it may still influence elasmobranch chondrogenesis over longer culture periods or indirectly through other regulatory pathways. Thus, further information is necessary to characterize the role of thyroid hormones in the skeletal growth of these fishes. The present study is the first in vitro investigation on the hormonal regulation of elasmobranch cartilage growth. As such, the methods described herein provide a useful technique for examining these physiological processes. J. Exp. Zool. 284:549-556, 1999.  相似文献   

5.
Summary In the present study the effects of lipopolysaccharide (LPS) on the cellular composition and phagocytosis of India ink in the inner parts of the periarteriolar lymphocyte sheaths (PALS) are described.Staining for B-, T-lymphocytes, and reticulin fibers in the spleen of normal and LPS-injected mice shows that the B-dependent follicular area is increased in size after LPS administration. However, the number of T-lymphocytes in the inner PALS is reduced markedly and a relatively high number of B-lymphocytes can be found in this area. The significance of this phenomenon is discussed.In untreated mouse spleen, carbon particles become localized in strongly acid-phosphatase (AP)-positive macrophages of the red pulp, marginal zone and white pulp 24 h after an intravenous injection of India ink. All these macrophages contain numerous carbon particles. After LPS pretreatment, the phagocytosis of carbon particles in the inner PALS is dramatically diminished, although many strongly AP-positive macrophages can be found in this area. The phagocytosis of carbon particles in the other compartments of the spleen did not change. It appears that injection of 2 g LPS or more is sufficient to induce this phenomenon which is most significant when LPS is injected 24 or 48 h before exposure to India ink.Abbreviations LPS lipopolysaccharide - PALS periarteriolar lymphocyte sheath - AP acid phosphatase - IDC interdigitating cells  相似文献   

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Hatching eggs from inbred lines of chickens (inbreeding coefficient exceeds 95%) which show various degrees of resistance and susceptibility to Rous sarcoma, were used for experimentation. Adult tissues were grafted onto the chorioallantois on the tenth day of incubation and tissues of host and control embryos were harvested on the twentieth day of incubation. Enzymes were localized in tissues by histochemical procedures. Small pieces of tissue (thymus or bursa), when grafted onto the chorioallantois, increased the size of the spleen in host embryos although splenomegaly did not invariably occur. Two types of reactions were observed in the spleen, i.e., enlarged spleens with cysts or enlarged spleens which from a morphological point of view were normal. Grafts of either thymus or bursa decreased the size of the host embryo's bursa or were without effect. When weight of the bursa of host embryos was significantly less than that of control embryos on the twentieth day of incubation, this size relationship persisted in chicks four weeks post hatching. Intensity of dehydrogenase and acid phosphatase reactions in cysts of enlarged spleens and in the multinucleated giant cells investing them suggests that they consist of groups of degenerating cells. Intensity of enzyme reaction indicates that enlarged spleens of host embryos in which cysts were absent were normal. Enzyme reactions in the bursae of experimental embryos were more intense than those identified in the same tissues of control embryos. Catabolic reactions were the predominant type in grafts ten days subsequent to implantation. Grafts increased the number of erythrocytes in the peripheral blood of host embryos.  相似文献   

8.
We compared the radiosensitivity of human, rat and mouse peripheral blood lymphocytes (PBLs) by analyzing micronuclei (MN) in cytochalasin B-induced binucleated (BN) cells. For each species and dose 4-ml aliquots of whole blood were X-irradiated to obtain doses of 38, 75, 150 or 300 cGy. Controls were sham-irradiated. After exposure to X-rays, mononuclear leukocytes were isolated using density gradients and cultured in RPMI 1640 medium containing phytohemagglutinin to stimulate mitogenesis. At 21 h cytochalasin B was added to produce BN PBLs, and all cultures were harvested at 52 h post-initiation using a cytocentrifuge. Significant dose-dependent increases in the percentage of micronucleated cells and the number of MN per BN cell were observed in all three species. The linear-quadratic regression curves for the total percentage of micronucleated cells for the three species were similar; however, the curve for the mouse PBLs had a larger quadratic component than either of the curves for the rat or human PBLs. Although the correlation between the percentage of cells with MN and those with chromosome aberrations was high (r2 greater than 0.95), the mouse and rat PBLs were over twice as efficient as human PBLs in forming MN from presumed acentric fragments. These data indicate that the induction of MN in BN cells following ionizing radiation is similar in human, rat and mouse PBLs, but care must be taken in using the MN results to predict frequencies of cells with chromosomal aberrations.  相似文献   

9.
The sensitivity of various methods suitable for biomonitoring the exposure to genotoxicants was compared in an animal model. The results were related to the presence of genotoxic effects in the target organ. Groups of male Wistar rats were given one oral dose of 0, 0.1, 10 or 200 mg 2-acetylaminofluorene (2-AAF)/5 ml dimethyl sulphoxide/kg body weight. Peripheral blood cells, excreta, liver and spleen were collected at different time intervals after dosing. Mutagenicity in urine and extracts of faeces was determined using the Ames test with Salmonella typhimurium TA98 with and without S9 and with and without beta-glucuronidase. Genotoxic effects were studied by measuring DNA-adduct formation in lymphocytes, liver and spleen, and sister-chromatid exchanges (SCEs) in lymphocytes. DNA adducts were measured with immunochemical techniques and postlabelling methods. Mutagenicity in urine and faeces, collected during the first 24 h after treatment, was detected at 2-AAF doses of 1 mg/kg b.w. and higher. At these doses DNA adducts also became apparent in the liver, the main target organ for tumour induction by 2-AAF. The adduct detected appeared to be the N-(deoxyguanosin-8-yl)-2-AAF adduct. There was no evidence of the presence of any other types of DNA adducts. At doses of 1 and 10 mg/kg b.w. no mutagenicity was detected in excreta collected during the second and third day after dosing. The DNA-adduct level in liver cells of the 1 mg/kg b.w. group was maximal 24 h after dosing. At 200 mg/kg b.w. a delay in excretion of mutagenicity with urine and faeces was seen and at 10 and 200 mg/kg b.w. the amount of DNA adducts continued to increase with time after dosing. At 24 and 48 h after treatment with 10 mg, the adduct levels were of the same order of magnitude as those found after the 20-fold higher dose. This points to overloading of the metabolizing system which in combination with the enterohepatic circulation, may lead to an increased retention of 2-AAF in the body. A slightly increased incidence of SCEs of doubtful significance was seen in lymphocytes, but only at the very high dose of 200 mg/kg b.w. No DNA adducts could be detected in blood lymphocytes or spleen cells at any of the dose levels applied, either with the immunochemical or with the postlabelling method.(ABSTRACT TRUNCATED AT 400 WORDS)  相似文献   

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Hsu CC  Huang YL  Tsai SJ  Sheu CC  Huang BM 《Life sciences》2003,73(16):2127-2136
The in vivo and in vitro effects of Cordyceps sinensis (CS) and its extracted fractions on the secretion of testosterone in mice were studied. CS, F2 (water soluble protein), and F3 (poorly water soluble polysaccharide and protein) significantly stimulated in vitro testosterone production in purified mouse Leydig cells. However, F1 (water soluble polysaccharide) had no effect (p>0.05). F2 and F3 stimulated in vitro testosterone production in dose- and time-dependent relationships with maximal responses at 3 mg/ml for 3 h (p<0.05). An in vivo study illustrated that testosterone levels in plasma were significantly increased by CS, F2, and F3, respectively (p<0.05). Because CS, F2, and F3 stimulated both in vitro and in vivo testosterone secretions in mice, it is possible that CS might contribute to an alternative medicine for the treatment of some reproductive problems caused by insufficient testosterone levels in human males.  相似文献   

13.
Vedolizumab (VDZ) is a humanized monoclonal antibody in development for the treatment of inflammatory bowel disease. VDZ binds to the α4β7 integrin complex and inhibits its binding to mucosal addressin cell adhesion molecule-1 (MAdCAM-1), thus preventing lymphocyte extravasation to gut mucosal tissues. To understand whether VDZ has additional effects that may affect its overall safety as a therapeutic molecule, we examined other potential actions of VDZ. In vitro assays with human peripheral blood lymphocytes demonstrated that VDZ fails to elicit cytotoxicity, lymphocyte activation, and cytokine production from memory T lymphocytes and does not interfere with the suppressive ability of regulatory T cells. Furthermore, we demonstrated that VDZ induces internalization of α4β7 and that the integrin is rapidly re-expressed and fully functional after VDZ withdrawal. These studies provide insight into the mechanisms underlying the observed safety profile of VDZ in clinical trials.  相似文献   

14.
目的:研究急性腹腔内感染对外周血及重要脏器内瘦素(Leptin)表达水平的影响,探讨Leptin在急性炎症反应中的作用。方法:建立大鼠盲肠结扎穿孔模型,设立假手术组和脂肪乳、单纯损伤、雌二醇、胰岛素组等实验组,采用放免分析法测量伤后12 h血清Leptin浓度,并用RT-PCR检测脂肪、肺及肝内Leptin mRNA表达的变化。结果:与伤后假手术组血清Leptin水平相比,其他四组与之无显著差异,但脂肪乳组显著高于单纯损伤和雌二醇组。与伤后假手术组Leptin mRNA表达水平相比,其他四组在脂肪、肺和肝内有不同程度的变化,脂肪乳组在脂肪内Leptin mRNA表达升高而在肺、肝内表达降低。结论:创伤后能量代谢和神经-内分泌功能的改变会影响Leptin的表达水平,提示Leptin可能作为一种保护因子参与恢复内环境稳定的过程。  相似文献   

15.
Bombesin-like immunoreactivity is present in nerve fibers projecting to the cardiovascular system, including the coronary arteries, and to the gastrointestinal canal, and in endocrine cells of the gut of skates belonging to the family Rajidae. Synthetic bombesin contracted isolated coronary rings from the longnose skate, Raja rhina, in a cumulative fashion. The contractile response was 84% of that of 60 mM potassium chloride. The pD2-value for bombesin was 8.83 (S.E.M. = 0.33; n = 15). Phentolamine, atropine and two substance P-antagonists increased the sensitivity to bombesin, while atenolol, sotalol, nifedipine, tetrodotoxin and two bombesin antagonists were devoid of significant effects. We conclude from this study that a bombesin-like peptide is present in nerves innervating the cardiovascular system and the gastrointestinal canal of skates of the family Rajidae, and that bombesin contracts coronary vessels in vitro via a direct mechanism and/or via mechanisms involving alpha-adrenergic and muscarinergic receptors.  相似文献   

16.
Antimony trioxide (Sb2O3), in aqueous suspension, was administered by gavaging to mice and monitored for chromosomal aberrations in bone marrow and sperm head abnormalities in germ cells. Acute exposur to the doses followed by observations after 6, 12, 18 and 24 h did not show any clastogenic effects. Chronic exposure daily to different doses for periods up to 21 days induced chromosornal aberrations in bone marrow. The frequencies were dose-dependent to a significant extent but no relationship could be seen with the sex of the animal. The findings indicate the harmful effects of cumulative exposure for prolonged periods to Sb2O3, which is being increasingly used in various industries.  相似文献   

17.
Before and after kidney transplantations, in vitro tests that measure the level of reactivity between donor and recipient lymphocytes are performed for better organ selection and as indicator of possible organ rejection. In these tests, donor's and recipient's lymphocytes are stimulated for proliferation, which intensity is measured and accordingly organ recipient reactivity towards graft is determined. Lymph node, spleen and peripheral blood lymphocytes are used for those purposes. For better interpretation of these in vitro tests it should be important to determine mitogenic ability of lymphocytes of different origin and to choose the most adequate cells. To compare mitogenic ability of deceased donor lymph node, spleen and peripheral blood lymphocytes one-way mixed lymphocyte culture (MLC) was used. As stimulators irradiated lymphocytes from spleen, lymph node and peripheral blood samples of 12 deceased donors were used while as responders lymphocytes from peripheral blood of healthy individuals, chosen according HLA-DRB1 alleles (stimulators and responders were HLA-DRB1 identical, semi-identical or different), were used. Spleen lymphocyte activity was the best with different cells and the weakest with identical cells. Impact of polyclonal mitogens (PHA - phytohemagglutinin, Con A - concanavalin A and PWM - pokeweed mitogen) on lymphocyte proliferation was tested on lymphocytes from spleen and lymph node of deceased donors. Results obtained in culture in vitro showed that spleen cells had exerted the best mitogenic potential and PHA had the greatest impact upon lymphocyte proliferation. This investigation is of importance for establishing the best model to reflect in vivo situation in transplanted patient.  相似文献   

18.
The effect of estrogens is mediated by activation of estrogen receptors (ERs). Because ER-α gene polymorphisms may exert different effects in childhood, we analyzed the associations between the IVS1 ?397T>C (PvuII) polymorphism and systemic inflammatory state, proangiogenic factors, frequency of monocyte subsets, lipid profile, blood pressure, and vascular complications in girls with type 1 diabetes mellitus (DM1). We examined 180 young girls with DM1 and 120 healthy age-matched controls. The analysis concerned PvuII polymorphism of the ER-α gene as well as the levels of serum inflammatory markers (CRP, IL-6, TNF-α), proangiogenic factors (VEGF, angiogenin), 17β-estradiol, values of monocyte subsets (CD14++CD16? and CD14+CD16+), lipid profile, and blood pressure. In our study, girls with CC genotype had lower level of inflammatory and angiogenic factors and lower frequencies of CD14+CD16+ monocytes in comparison to CT or TT carriers. Simultaneously, the CC carriers had a greater population of CD14++CD16? monocytes, increased blood pressure, and serum levels of: estrogen, total cholesterol, triglycerides, and low-density lipoprotein cholesterol than girls bearing CT or TT genotype. Our study suggests a pleiotropic effect of PvuII polymorphic CC variant on diabetic vasculopathies. Although the CC genotype carriers demonstrate less inflammatory and angiogenic activity, they seem to display less favorable cardiometabolic features. Based on our study, we cannot distinguish PvuII ER-α genotype that could be useful in identification of DM1 girls that are more prone to develop of late vascular complications, before the occurrence of first clinical symptoms.  相似文献   

19.
Synopsis Raja erinacea and R. ocellata are sibling species which are positively correlated with each other by occurrence and numerical abundance. In sympatry the species undergo interactive segregation; R. erinacea feeds on a higher percentage of epifauna and R. ocellata feeds on a higher percentage of infauna.An isolated allopatric population of R. ocellata occurs in the Gulf of St. Lawrence which is phenotypically intermediate between the sympatric populations of R. erinacea and R. ocellata in characters related to feeding e.g. size, number of tooth rows in the upper jaw, and shape of the upper jaw. It appears probable that the allopatric population represents the morphological state of R. ocellata before it became sympatric with R. erinacea; divergence in size, number of tooth rows, and shape of the upper jaw between the two species developed after establishment of sympatry. These divergences in character traits, related to feeding, reduced competition between the two sympatric species and permitted the present wide overlap in their ranges.Character displacement is evidently rare in demersal fishes inhabiting the flat and soft bottoms of the northwestern Atlantic because the three other pairs of sibling species that occur there are parapatrically distributed and thus would not compete for resources. Raja erinacea and R. ocellata may have been restrained from establishing parapatry by another species pair of skates (R. senta and R. radiata) which have a complementary distribution and similar feeding habits of R. erinacea and R. ocellata but which occur in deeper water.  相似文献   

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