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111.
Content of red blood-cell sialic acid in BW 35 blood donors. Relation to magnesium concentration and pyruvate kinase activity 总被引:1,自引:0,他引:1
Previous studies have shown that the concentration of red blood cell (RBC) magnesium is significantly lower in subjects carrying an HLA-BW 35 antigen (p less than 0.001) than in non-carriers. As this finding might be related to modifications of the RBC membrane sialoglycoconjugates, RBC sialic acid was comparatively determined in BW 35+ and BW 35- subjects. Pyruvate-kinase activity mean RBC volume, and reticulocyte count have also been determined in order to estimate whether some significant variations in the level of these age markers could be detected between the HLA BW 35+ and BW 35- subjects. A significant negative correlation between sialic acid and RBC magnesium concentrations was observed for the whole population tested (n 57, p less than 0.005), 61% of the BW 35+ and only 25% of the BW 35- individuals having sialic acid values above, and magnesium values below the overall mean (p less than 0.01). The variance of mean RBC volume was also larger for the BW 35+ group. Other determinations did not show any significant variations, suggesting that the results are not related to RBC age. 相似文献
112.
Fumaria capreolata was taken into cell suspension culture. The culture yielded a biomass of about 12 g dry weight per liter of medium; the dried cells contained ca. 0.1% of alkaloids. Besides choline, the following ten known isoquinoline alkaloids were isolated from the cell extract in crystalline form: coptisine, dehydrocheilanthifoline; (+)-isoboldine; magnoflorine; N-methylcoclaurine; (+)-reticuline; (–)-pallidine; protopine; sanguinarine; (–)-scoulerine. This is the most diverse isoquinoline alkaloid spectrum thus far published for a cell suspension culture. 相似文献
113.
The role of polyamines in animal cell physiology 总被引:3,自引:0,他引:3
M H Goyns 《Journal of theoretical biology》1982,97(4):577-589
The ubiquitous distribution of polyamines in nature suggests that they fulfil some fundamental role(s) in living organisms. In animal cells, polyamine content closely parallels changes in the rate of cell proliferation so that the highest content is always observed in rapidly growing cells. The activity of ornithine decarboxylase (which is the first enzyme in the polyamine biosynthetic pathway) has been found to increase significantly in many systems shortly after exposure to hormones. Also, addition of polyamines greatly stimulates cell-free macromolecular synthesis. Observations such as these have suggested that polyamine accumulation stimulates cell growth and is important in the regulation of macromolecular biosynthesis. However, it is also possible to interpret such data as evidence that polyamine accumulation is the result, not the cause, of increased cell growth. This review supports the latter concept and re-examines the significance of the early induction of ornithine decarboxylase activity and of the stimulatory effects of exogenous polyamine on macromolecular synthesis. It is proposed that the polyamines are important only in maintaining cell growth that has already been stimulated by other factors and that their biosynthesis is to a large extent determined by the accumulation of RNA in the cell. 相似文献
114.
V A Frolov G Mall P Rieger Kh Derks Z Antoni 《Biulleten' eksperimental'no? biologii i meditsiny》1987,104(12):739-741
Intensive synthesis of collagen-like substance was revealed in the rabbit myocardium during experimental diphtheria intoxication. It was more marked in the right ventricle 24 hours after the injection of diphtheria toxin. Since similar changes (the substance was mainly formed around blood vessels) have been observed in other cases of toxic myocardial alterations (i.e. ethanol intoxication, injection of pharmacological agents, etc.), it can be assumed that it is a standard protective reaction of the altered heart to the penetration of toxic agents from the blood into the myocardial tissue. 相似文献
115.
EEG activity was recorded in rats submitted to osmotic opening of the BBB by intracarotid mannitol infusion.This procedure produced an immediate short-lasting depression of the EEG and a tardive paroxysmal EEG activity. Both these phenomena were more relevant on the ipsilateral hemisphere. In some instances a tonico-clonic seizure was recorded.Pre-treatment with diazepam abolished the occurrence of the tardive EEG and behavioral modifications.In accord with previous findings, focal seizure activity is likely to be responsible for the metabolic abnormalities associated with osmotic opening of the BBB. This preparation therefore produces in the brain unphysiological states in respect to local metabolism and electrical function. 相似文献
116.
R Blomhoff W Eskild G M Kindberg K Prydz T Berg 《The Journal of biological chemistry》1985,260(25):13566-13570
The intracellular transport of chylomicron remnants labeled with [3H]retinyl ester was studied in rat liver parenchymal cells by means of subcellular fractionation in Nycodenz and sucrose density gradients. The data presented indicate that endocytosed chylomicron remnant [3H]retinyl ester initially is located in low density endosomes. Radioactivity is subsequently transferred to a denser vesicle. Equilibrium as well as rate zonal centrifugation suggest that this denser [3H] retinoid-containing vesicle may represent endoplasmic reticulum. We have compared the intracellular transport of chylomicron remnant [3H]retinyl ester and 125I-asialofetuin. The receptor-mediated endocytosis of asialoglycoproteins in rat liver parenchymal cells is a thoroughly studied system. Our results suggest that the [3H] retinoid and 125I-asialofetuin follow the same path initially to the endosomes. After transit in endosomes, the intracellular transport differs. While asialofetuin is transported to the lysosomes, the retinoid is probably transferred to the endoplasmic reticulum. 相似文献
117.
118.
A.M. Ageel K.E.H. El-Tahir A.R. Abu-Jayyb 《Prostaglandins & other lipid mediators》1985,30(3):369-381
The effect of bromocriptine mesylate on cyclic nucleotides and PGI2 release by rat aortic and uterine tissues was investigated. Treatment of rats with bromocriptine (10 mg kg−1 I.P. daily for 14 days) increased PGI2 release by the thoracic aorta from 0.67 ± 0.02 to 1.4 ± 0.03 ng/mg wet tissue (P < 0.001; n = 6). This increase was antagonized by treatment with sulpiride (15 mg kg−1). Incubation of the arterial tissue with bromocriptive (50 ug ml−) in vitro also stimulated PGI2 release. Mepacrine (160 μg ml−) significantly decreased both basal and stimulated PGI2 release. Incubation of myometrial tissue from pregnant rats with bromocriptine (50 μg ml−1) in vitro significantly decreased PGI2 release from 1.25 ± 0.07 to 0.60 ± 0.08 ng/mg wet tissue (P < 0.05, n = 6).It also elevated uterine cAMP from 40 ± 2 to 64 ± 3 pmoles/100 mg wet tissue. Both effects were antagonized by sulpiride. Bromocriptine did not affect uterine cGMP or the cyclic nucleotides in the aorta. It is concluded that the increase in aortic PGI2 was mediated via activation of dopamine D-2 receptors that stimulate phospholipase A2 enzyme. The decrease in myometrial PGI2 release may be related to the increase in uterine cAMP resulting from activation of dopamine D-1 receptors. Previous studies suggested a role for PGI2 in implantation in the rat. The results suggest that the inhibitory effèct on uterine PGI2 may underlie the reported inhibition of bromocriptine on implantation. On broad basis, the decrease in uterine PGI2 together with the reported luteolytic effect of bromocriptine point to a potential role for the compound in postcoital contraception. 相似文献
119.
Adenine uptake by isolated rat thymocytes 总被引:1,自引:0,他引:1
P H Cartier 《The Journal of biological chemistry》1980,255(10):4574-4582
120.
K N Iarygin A N Kazimirski? G I Kositski? A Iu Rubina V A Vinogradov 《Biulleten' eksperimental'no? biologii i meditsiny》1986,101(6):680-682
The authors studied the anabolic effect of peptide morphogen of the hydra undecapeptide on normal and regenerating rat liver. Ornithine decarboxylase (EC 4.1.1.17) activity served as a marker. Intraperitoneal injection of the peptide into intact animals stimulated ornithine decarboxylase activity in a dose-dependent manner. In partially hepatectomized rats the peptide stimulated ornithine decarboxylase activity in the dose of 20 micrograms/kg body weight while greater doses inhibited the enzyme activity. 相似文献