Maximale tubuläre Zuckerresorption (Tmg) und Phosphorylierung

Summary Tmg (maximal tubular reabsorption of glucose) can be raised enormously by intravenous administration of Percorten. Therefore we suggest that the degree of reabsorption of glucose depends on the power of phosphorylation of the tubular tissue.     

在二甲亚砜溶剂中氯化钼氧卟啉和超氧自由基反应动力学研究Ⅱ反应网络

本文研究了Ｍｏ￣ⅤＯ（ＴＰＰ）Ｃｌ与Ｏ＿２的反应机理。结果表明，在１：１体积比ＣＨ＿２Ｃｌ＿２－ＤＭＳＯ溶剂中，在１８－ｃｒｏｗｎ－６存在下，配合物Ｍｏ￣ⅤＯ（ＴＰＰ）Ｃｌ被Ｏ￣－＿２还原的反应通过一系列中间物，最后生成Ｍｏ￣ⅣＯ（ＴＰＰ）（１８－ｃｒｏｗｎ－６），本文给出了详细的反应动力学网络。     

Characterization of the third component of pig complement and its utilization in a C3b receptor study

Summary The third component of the pig complement system (C3) was isolated in hemolytically active form and characterized. The C3 component is a -globulin with the molecular weight of 191,000 and is composed of 2 non-identical polypeptide chains of M_t 112,000 and 74,000. The isolated C3 can be used for the detection of the C3b receptor on the membranes of heterologous peritoneal macrophages.     

Changes in mouse liver superoxide dismutase activity and lipid peroxidation during embryonic and postpartum development

Summary In inbred mice possessing high and low tissue superoxide dismutase (SOD) activity, it was observed that the difference in the SOD activities of the liver homogenates during development attains the maximum characteristic of the strain by about the 150th day. Subsequently, the SOD activity change displays a tendency in contrast with the age and the basic state. In the course of the development, a difference was also observed between the 2 mouse strains in the lipid peroxidation variation.Part XVIII of the series Properties of enzymes.     

Ovarian function in adult rats treated with antithymocyte serum

Summary Intraperitoneal treatment of adult rats with antithymocyte serum for 2 weeks altered the ovarian function. During the treatment, anovulation with the persistence of corpora lutea and a tendency toward a permanent diestrous state was observed.     

Night pineal N-acetyltransferase activity in rats exposed to white or red light pulses of various intensity and duration

Summary Night N-acetyltransferase activity is suppressed by red and white light; the red light intensity, however, must be 10 times higher. Short light pulses also suppress night N-acetyltransferase; the higher the light intensity, the shorter the pulse is effective.The authors are grateful to Mrs Marie Svobodová for her skillful technical assistance.     

Melanoma cells exhibit strong intracellular TASK-3-specific immunopositivity in both tissue sections and cell culture

Amplification of the kcnk9 gene and overexpression of the encoded channel protein (TASK-3) seems to be involved in carcinogenesis. In the present work, TASK-3 expression of melanoma cells has been studied. For the investigation of TASK-3-specific immunolabelling, a monoclonal antibody has been developed and applied along with two, commercially available polyclonal antibodies targeting different epitopes of the channel protein. Both primary and metastatic melanoma cells proved to be TASK-3 positive, showing prominent intracellular TASK-3-specific labelling; mostly concentrating around or in the proximity of the nuclei. The immunoreaction was associated with the nuclear envelope, and with the processes of the cells and it was also present in the cell surface membrane. Specificity of the immunolabelling was confirmed by Western blot and transfection experiments. As TASK-3 immunopositivity of benign melanocytes could also be demonstrated, the presence or absence of TASK-3 channels cannot differentiate between malignant and non-malignant melanocytic tumours.     

Characterization of the role of metallothionein-3 in an animal model of Alzheimer’s disease

Among the dementias, Alzheimer’s disease (AD) is the most commonly diagnosed, but there are still no effective drugs available for its treatment. It has been suggested that metallothionein-3 (MT-3) could be somehow involved in the etiology of AD, and in fact very promising results have been found in in vitro studies, but the role of MT-3 in vivo needs further analysis. In this study, we analyzed the role of MT-3 in a mouse model of AD, Tg2576 mice, which overexpress human Amyloid Precursor Protein (hAPP) with the Swedish mutation. MT-3 deficiency partially rescued the APP-induced mortality of females, and mildly affected APP-induced changes in behavior assessed in the hole-board and plus-maze tests in a gender-dependent manner. Amyloid plaque burden and/or hAPP expression were decreased in the cortex and hippocampus of MT-3-deficient females. Interestingly, exogenously administered Zn₇MT-3 increased soluble Aβ40 and Aβ42 and amyloid plaques and gliosis, particularly in the cortex, and changed several behavioral traits (increased deambulation and exploration and decreased anxiety). These results highlight that the control of the endogenous production and/or action of MT-3 could represent a powerful therapeutic target in AD.