3-Hydroxykynurenine (3-HK) is a tryptophan metabolite whose level in the brain is elevated under several pathological states including Huntington's disease. In the present study, we examined the possible toxicity of 3-HK by injection of this substance into rat brain. Intrastriatal injection of 3-HK (50 nmol) induced tissue damage around the injected site. Quinolinic acid (QA) at 200 nmol also i...

Low and high molecular weight kininogens (LK and HK), containing 409 and 626 amino acids with masses of approximately 65 and 120 kDa after glycosylation, respectively, are coded by a single gene mapped to the human chromosome 3 by alternative splicing of the transcribed mRNA. The NH2-termini Glu1-Thr383 region, identical in LK and HK, contains bradykinin (BK) moieties Arg363-Arg371. LK, HK and ...

BACKGROUND Hexokinase-2(HK-2) plays dual roles in glucose metabolism and mediation of cell apoptosis, making it an attractive target for cancer therapy. Chrysin is a natural flavone found in plant extracts which are widely used as herb medicine in China. In the present study, we investigated the antitumor activity of chrysin against hepatocellular carcinoma (HCC) and the role of HK-2 played for...

introduction: although hippocampus is the most famous brain area involved in temporal lobe epilepsy, hippocampal kindling (hk) develops very slowly. hence, rapid kindling is usually preferred to the traditional kindling and it is widely used. in this article we aimed at finding the optimal stimulus pattern, which yields the fastest hk rate. methods: stimulus patterns with different duration (2,...

PURPOSE To detect endogenous substance P (SP) and neurokinin receptor 1 (NK1R) in cultured human corneal epithelial cells (HE) and cultured human keratocytes (HK). METHODS Messenger RNA (mRNA) expression of SP and endogenous SP in HE and HK was investigated by reverse transcription-polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay. mRNA expression of NK1R in HE and HK w...

The nonenzymatic cofactor high molecular weight kininogen (HK) is a precursor of bradykinin (BK). The production of BK from HK by plasma kallikrein has been implicated in the pathogenesis of inflammation and vascular injury. However, the functional role of HK in the absence of prekallikrein (PK), the proenzyme of plasma kallikrein, on vascular endothelial cells is not fully defined. In addition...

Two-component signal transduction systems, consisting of histidine kinase (HK) sensors and DNA-binding response regulators, allow bacteria and archaea to respond to diverse environmental stimuli. HKs possess a conserved domain (H-box region) which contains the site of phosphorylation and an ATP-binding kinase domain. In this study, a genomic approach was taken to analyse the HK family in bacter...

The plasma zymogens factor XI (fXI) and prekallikrein (PK) are activated by factor XIIa (fXIIa) during contact activation. Polyanions such as DNA and RNA may contribute to thrombosis and inflammation partly by enhancing PK and fXI activation. We examined PK and fXI activation in the presence of nucleic acids, and determine the effects of the cofactor high molecular weight kininogen (HK) on the ...

We have recently reported that liposomes in combination with histidine (HK)-containing polymers enhanced the expression of luciferase in transfected cells. In transformed or malignant cell lines, branched HK polymers (combined with liposome carriers) were significantly more effective than the linear HK polymer in stimulating gene expression. In the current study, we found that the linear HK pol...

Expression of the hexokinase (HK) II gene in skeletal muscle is upregulated by electrically stimulated muscle contraction and moderate-intensity exercise. However, the molecular mechanism by which this occurs is unknown. Alterations in intracellular Ca(2+) homeostasis accompany contraction and regulate gene expression in contracting skeletal muscle. Therefore, as a first step in understanding t...