Delta-sleep-inducing peptide (DSIP) stimulates the release of immunoreactive Met-enkephalin from rat lower brainstem slices in vitro

We studied whether delta-sleep-inducing peptide (DSIP) acted on opioid receptor directly or indirectly. DSIP did not have binding activity to any subtype of opioid receptors. DSIP at doses of 1 pM-1 nM significantly stimulated the release of immunoreactive Met-enkephalin (iME) from superfused slices of the rat lower brainstem. The DSIP-induced release of iME was calcium-dependent. These results show that DSIP acts on opioid receptor indirectly by stimulating the release of iME in producing antinociceptive effects.     

Effects of interferon on the cell cycle of human hepatoma HLF cells analyzed by flow cytometry

Growth inhibition by interferon (IFN) was investigated in human hepatoma HLF cells by use of flow cytometry to study the cell cycle. INF-alpha or -beta inhibited growth more than IFN-gamma. Use of either IFN-alpha or -beta and IFN-gamma at the same time inhibited growth more than with any one kind of IFN, but use of IFN-alpha and -beta together did not cause much inhibition. IFN inhibited growth by causing cells to accumulate in the S phase instead of moving on to the G2 phase. Accumulation in the S phase was less with IFN-gamma than with -alpha or -beta. It increased with the combination of IFN-alpha or -beta with IFN-gamma, but not with the combination of IFN-alpha and -beta.     

Regional distribution of a novel analgesic dipeptide kyotorphin (Tyr-Arg) in the rat brain and spinal cord

Using high performance liquid chromatography, we measured kyotorphin content in discrete regions of the rat brain and spinal cord in an attempt to clarify its physiological significance. Higher concentrations of the dipeptide were found in the midbrain, pons plus medulla oblongata and dorsal cord, which are the most sensitive sites for the microinjection of morphine and/or electrical stimulation-induced analgesia. Kyotorphin may play a physiological role in pain control in the central nervous system.     

Occurence of a skin toxin in coral-globes Gobiodon Spp

Coral-gobies Gobiodon spp. contain a skin toxin having a stinging and bitter taste, ichthyotoxicity and hemolytic activity. The skin possessed peculiar secretory cells assumed to secrete the toxin. When the whole fish or epidermis was stored without preheating, the toxin disappeared rapidly, probably due to enzymatic degradation. The toxin of Gobiodon quinquestrigatus was obtained from the epidermis by extraction with ethanol and purified by precipitation at 25 per cent saturation of NaCl, countercurrent distribution, and Sephadex LH-20 column chromatography. In thin layer chromatography the final preparation still gave three spots, each positive to Dragendorff reagent, ninhydrin, and each having hemolytic activity. The toxin was easily dialyzable through a cellophane membrane and showed an absorption band at around 260 nm. The amino acid composition was very similar to that of the 1-butanolic extract from the mucus of a soapfish Pogonoperca punctata and the toxin was assumed like grammistin to be a mixture of peptides containing a tertiary or quaternary amine moiety.     

ADAM28 is overexpressed in human non-small cell lung carcinomas and correlates with cell proliferation and lymph node metastasis

ADAM (a disintegrin and metalloproteinases) are a recently discovered gene family of proteins with sequence similarity to the reprolysin family of snake venom metalloproteinases, and about one-third of the family members have the catalytic site consensus sequence in their metalloproteinase domains. We screened the mRNA expression of 11 different ADAM species with putative metalloproteinase activity in human non-small cell lung carcinomas by RT-PCR, and found that prototype membrane-anchored ADAM28 (ADAM28m) and secreted ADAM28 (ADAM28s) are predominantly expressed in the carcinoma tissues. Real-time quantitative PCR demonstrated that the expression levels of ADAM28m and ADAM28s are significantly 16.8-fold and 9.0-fold higher in the carcinomas than in the non-carcinoma tissues, respectively. In addition, the expression levels of ADAM28m and ADAM28s were significantly higher in the carcinomas with >30 mm in diameter than in those < or =30 mm. The expression levels were also significantly higher in the carcinomas with lymph node metastasis than in those without metastasis. MIB1-positive cell index of the carcinomas had a direct correlation with the expression levels of ADAM28m and ADAM28s (r = 0.667, p < 0.001 and r = 0.535, p < 0.01, respectively). In situ hybridization and immunohistochemistry demonstrated that ADAM28 is expressed predominantly in the carcinoma cells. Immunoblot analysis showed the activated form of ADAM28 in the carcinoma tissues. These data demonstrate for the first time that ADAM28 is overexpressed and activated in human non-small cell lung carcinomas, and suggest the possibility that ADAM28 plays a role in cell proliferation and progression of the human lung carcinomas.