[Study on changes of content of Tannin in Nodus Nelumbinis Rhizomatis Charcoal].

OBJECTIVE: To determine changes of content of Tannin in different Nodus Nelumbinis Rhizomatis Charcoal. METHODS: The content of Tannin of Nodus Nelumbinis Rhizomatis Charcoal was detected by UV and colorimetric method. RESULTS: The content of tannin in standard sample was the highest. CONCLUSION: It should be studied whether the tannin of Nodus Nelumbinis Rhizomatis Charcoal is the active ingredients of hemostasis.

Identification and expression profile of a putative basement membrane protein gene in the midgut of Helicoverpa armigera.

BACKGROUND: The midgut undergoes histolysis and remodeling during the larval to adult transition in holometabolous insects, but the molecular mechanisms underlying this process are not well understood. RESULTS: Using Suppression Subtractive Hybridization (SSH), we identified a 531 bp cDNA predicted to encode a 176 amino acid protein, which we call hmg176. Northern and western blot analysis suggested that high levels of hmg176 are expressed in the midgut during molting, but not during metamorphosis. HMG176 protein was detected by immunofluorescence within the membrane of fat bodies and the basement membrane of the midgut of both molting and feeding larvae, but not in metamorphically committed larvae. In situ hybridization revealed that hmg176 transcripts mainly localized to the columnar cells of the midgut. Interestingly, a non-steroidal ecdysone agonist, RH-2485, significantly upregulated expression of hmg176. CONCLUSION: These observations suggest that hmg176 encodes a larval-specific protein that may participate in sustaining larval midgut during larval development, possibly in response to ecdysteroid in vivo. This study will enlighten our understanding of the molecular mechanisms of tissue histolysis during metamorphosis.

Expression and function of cathepsin B-like proteinase in larval hemocytes of Helicoverpa armigera during metamorphosis.

Previous work has revealed that Helicoverpa armigera cathepsin B-like proteinase (HCB) is expressed in oocytes as well as fat bodies of pupae and adults. It plays key roles in the degradation of yolk proteins during embryogenesis and the decomposition of adult fat bodies of H. armigera. This study investigated the expression and function of HCB in larval hemocytes during larva-pupa metamorphosis. Results showed that the expression of HCB in hemocytes exhibited developmental stage specificity. No HCB was found in hemocytes from 5th-molting larvae. On the contrary, HCB was highly transcribed in the hemocytes from 6th-48-h larvae. Besides, it was abundantly translated in 6th-96-h larvae (prepupation). HCB is mainly expressed in plasmatocytes and granulocytes at both transcriptional and translational levels. The number of plasmatocytes and granulocytes markedly increased before pupation. In addition, hemocytes distributed in hematopoietic organs at early larval stage, then migrated to midgut and fat bodies that would undergo histolysis at later larval stage. These findings suggested that HCB is expressed in H. armigera larval hemocytes and involved in larva-pupa metamorphosis.

Cathepsin B-like proteinase is involved in the decomposition of the adult fat body of Helicoverpa armigera.

Cathepsin B-like proteinase (HCB, EC 3.4.22.1) is expressed in Helicoverpa armigera oocytes and adult fat bodies. Previous work has revealed that HCB plays a key role in the degradation of yolk proteins during embryogenesis. This study investigated the function and regulatory activation of HCB in adult fat bodies during aging and oogenesis. The HCB transcript was detected at all stages from larval to adult fat bodies with Northern blot analysis. Pro-HCB was also detected in fat bodies at these stages with an immunoblot assay using a monoclonal antibody against HCB. However, mature HCB and its activity were only detected in fat bodies of pre-adults and adults. This evidence suggested that HCB is regulated post-translationally by activation of the pro-enzyme during the pupa-adult metamorphosis. The activation of HCB was coupled with the expression of hormone receptor 3 (HHR3), and was up-regulated by the ecdysteroid agonist, RH-2485, suggesting that HCB activation is related to the ecdysone regulatory system. The decomposition of the adult fat bodies during aging and oogenesis was found to occur via programmed cell death, in which HCB took part.