AIMTo study the protection of casein and protamine against degradation of insulin (INS) by proteolysis enzymes and the effect of these two kinds of protein on the hypoglycemic action of INS solution and enteric-microspheres after administrated orally to rats.

METHODSHPLC was used to determine the remained INS in the solution of alpha-chymotrypsin and trypsin with or without casein or protamine; INS solution and enteric-microspheres were prepared and adiministrated orally to rats together with the absorption enhancer sodium N-[8-(2-hydroxybenzoyl) amino] caprylate (SNAC). At the same time, casein or protamine or both of these two kinds of protein were administrated together in order to study their influence on the hypoglycemic effect of INS and microspheres.

RESULTSCasein had a good protection against degradation of INS by alpha-chymotrypsin, but protamine had no protection effect. However, the degradation of INS by trypsin is concerned, the protection effect of protamine on INS was better that of casein. Both of protamine and casein can increase the hypoglycemic effect of INS solution and enteric-microspheres. Co-administrated these two kinds of protein had a better effect. In addition, co-administrated with SNAC, casein and protamine, INS enteric-microspheres had a longer and more potent hypoglycemic effect than that of the solution.

CONCLUSIONCasein and protamine can increase the stability of INS in the intestinal fluid by the mechanism of competition and combine with proteolysis enzymes, which will benefit to INS oral administration.

Administration, Oral ; Animals ; Blood Glucose ; metabolism ; Caprylates ; Caseins ; pharmacology ; Chymotrypsin ; antagonists & inhibitors ; Drug Delivery Systems ; Hypoglycemic Agents ; administration & dosage ; pharmacokinetics ; Insulin ; administration & dosage ; pharmacokinetics ; Male ; Microspheres ; Protamines ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Solutions ; Trypsin ; pharmacology

A soluble factor which augments the expression of major histocompatibility complex class I (MHC I) antigens on a number of murine tumor cell lines, has been isolated from the culture supernatants of mixed lymphocyte reaction of spleen cells derived from C57B1/6, Balb/c and Swiss mice. The factor, termed MHC-augmenting factor (MHC-AF) has been partially purified by Sephadex G-100 column chromatography and reverse phase HPLC. MHC-AF activity is associated with an 18 kDa molecule. MHC-AF activity was resistant to pH 2.0 treatment and partially purified MHC-AF preparations did not have any activity in L929 cell/vesicular stomatitis virus (VSV) interferon bioassay system. Antibodies to IFN-gamma did not block the activity of MHC-AF. These results indicate that a MHC-AF distinct from IFN-gamma, is produced by mouse spleen cells undergoing a mixed lymphocyte reaction.
Animal ; Antibodies/pharmacology ; Chymotrypsin/metabolism ; Chymotrypsin/chemistry ; Comparative Study ; Concanavalin A/pharmacology ; Heat ; Histocompatibility Antigens Class I/metabolism* ; Histocompatibility Antigens Class I/drug effects ; Interferon Type II/pharmacology ; Interferon Type II/metabolism ; Interferon Type II/immunology ; Lymphocytes/physiology ; Mice ; Mice, Inbred BALB C ; Mice, Inbred C57BL ; Proteins/pharmacology* ; Proteins/metabolism ; Proteins/isolation & purification* ; Spleen/cytology ; Trypsin/metabolism ; Trypsin/chemistry ; Tumor Cells, Cultured/immunology ; Tumor Cells, Cultured/drug effects

PURPOSE: Although the proteasome inhibitor known as bortezomib can modulate the inflammatory process through the nuclear factor-kappa B signaling pathway, the immunomodulatory effect of pre-incubated bortezomib has not been fully evaluated for inflammation by infectious agents. Therefore, we evaluated the effect of bortezomib on the expression of inflammatory cytokines and mediators in macrophage cell lines and on survival in a murine peritonitis sepsis model. MATERIALS AND METHODS: Bortezomib was applied 1 hr before lipopolysaccharide (LPS) stimulation in RAW 264.7 cells. The cecal ligation and puncture (CLP) experiments were performed in C57BL/6J mice. RESULTS: Pre-incubation with bortezomib (25 nM or 50 nM) prior to LPS (50 ng/mL or 100 ng/mL) stimulation significantly recovered the number of viable RAW 264.7 cells compared to those samples without pre-incubation. Bortezomib decreased various inflammatory cytokines as well as nitric oxide production in LPS-stimulated cells. The 7-day survival rate in mice that had received bortezomib at 0.01 mg/kg concentration 1 hr prior to CLP was significantly higher than in the mice that had only received a normal saline solution of 1 mL 1 hr prior to CLP. In addition, the administration of bortezomib at 0.01 mg/kg concentration 1 hr before CLP resulted in a significant decrease in inflammation of the lung parenchyma. Collectively, pretreatment with bortezomib showed an increase in the survival rate and changes in the levels of inflammatory mediators. CONCLUSION: These results support the possibility of pretreatment with bortezomib as a new therapeutic target for the treatment of overwhelming inflammation, which is a characteristic of severe sepsis.
Animals ; Boronic Acids/administration & dosage/pharmacology/*therapeutic use ; Cecum/*pathology ; Cell Adhesion Molecules/metabolism ; Cell Line ; Cell Proliferation/drug effects ; Cell Survival/drug effects ; Chymotrypsin/metabolism ; Cytokines/*metabolism ; Disease Models, Animal ; Inflammation Mediators/*metabolism ; Ligation ; Lipopolysaccharides/pharmacology ; Lung/drug effects/metabolism/pathology ; Male ; Mice, Inbred C57BL ; Nitric Oxide/metabolism ; Proteasome Inhibitors/pharmacology ; Punctures ; Pyrazines/administration & dosage/pharmacology/*therapeutic use ; Sepsis/*drug therapy

Mouse spleen cells activated in a mixed lymphocyte reaction release a soluble factor, which induces a significant proliferative response in fresh mouse spleen cells. This proliferation inducing factor (PIF) was found to be heat stable (90 degrees C for 45 min) and also resistant to trypsin or chymotrypsin treatment. By using a sizing HPLC column, the molecular weight of PIF appears to be 25 kDa. Mouse spleen cells treated with anti-thy-1 + complement lost Con-A induced proliferative responses but responded well to PIF. B cell depleted spleen cells obtained by negative selection panning, did not respond to PIF. These results indicate that B cells proliferated in response to PIF. Polymixin-B, which blocks the B cell proliferative response to LPS, did not inhibit PIF induced proliferation.
Animal ; B-Lymphocytes/physiology* ; B-Lymphocytes/drug effects ; Bone Marrow/metabolism ; Cell Division/physiology ; Chromatography, High Pressure Liquid ; Chymotrypsin/pharmacology ; Dose-Response Relationship, Drug ; Growth Substances/pharmacology* ; Growth Substances/chemistry ; Heat ; Mice ; Mice, Inbred BALB C ; Mice, Inbred C57BL ; Molecular Weight ; Polymyxin B/pharmacology ; Protein Denaturation ; Spleen/metabolism* ; Thymus Gland/metabolism ; Trypsin/pharmacology