Complement C5a exhibits anxiolytic-like activity via the prostaglandin D2-DP1 receptor system coupled to adenosine A2A and GABAA receptors

We have recently found that central PGD(2) exhibits anxiolytic-like activity. Here we show that complement C5a exhibits anxiolytic-like activity via the PGD(2) system. Centrally administered C5a had anxiolytic-like activity at a dose of 0.3 pmol/mouse in the elevated plus-maze test in mice. C5a-induced anxiolytic-like activity was inhibited by indomethacin, a cyclooxygenase inhibitor, or BWA868C, an antagonist of DP(1) receptor for PGD(2), respectively. The anxiolytic effect of C5a was also blocked by SCH58261 or bicuculline, antagonists of adenosine A(2A) and GABA(A) receptors, respectively, which were activated downstream of PGD(2)-DP(1) receptor. These results suggest that C5a exhibits anxiolytic-like activity via the PGD(2)-DP(1) receptor system coupled to the activation of adenosine A(2A) and GABA(A) receptors.     

Molecular phylogeny and biogeography of caecilians from Southeast Asia (Amphibia, Gymnophiona, Ichthyophiidae), with special reference to high cryptic species diversity in Sundaland

We investigated the phylogenetic relationships and estimated the history of species diversification and character evolution in two ichthyophiid genera: Caudacaecilia and Ichthyophis. We estimated the phylogenetic relationships of 67 samples from 33 localities in Southeast Asia from 3840-bp sequences of the mitochondrial 12S rRNA, 16S rRNA, and cyt b genes using Bayesian inference, maximum likelihood, and maximum parsimony methods. The Southeast Asian samples formed a well-supported clade differentiated from a South Asian sample. The Southeast Asian clade was divided into two subclades, one containing samples from South China, Indochina, Malay Peninsula, and Java. The other consisted of samples from Borneo and the Philippines. Neither Caudacaecilia nor Ichthyophis was monophyletic, nor did samples with or without light stripes lateral to the body form clades. We found several distinct sympatric lineages and undescribed species, especially from Sundaland.     

Characterization of a cellular retinol-binding protein from lamprey, Lethenteron japonicum

Lampreys are ancestral representatives of vertebrates known as jawless fish. The Japanese lamprey, Lethenteron japonicum, is a parasitic member of the lampreys known to store large amounts of vitamin A within its body. How this storage is achieved, however, is wholly unknown. Within the body, the absorption, transfer and metabolism of vitamin A are regulated by a family of proteins called retinoid-binding proteins. Here we have cloned a cDNA for cellular retinol-binding protein (CRBP) from the Japanese lamprey, and phylogenetic analysis suggests that lamprey CRBP is an ancestor of both CRBP I and II. The lamprey CRBP protein was expressed in bacteria and purified. Binding of the lamprey CRBP to retinol (Kd of 13.2 nM) was identified by fluorimetric titration. However, results obtained with the protein fluorescence quenching technique indicated that lamprey CRBP does not bind to retinal. Northern blot analysis showed that lamprey CRBP mRNA was ubiquitously expressed, although expression was most abundant in the intestine. Together, these results suggest that lamprey CRBP has an important role in absorbing vitamin A from the blood of host animals.     

Electrocardiograms in five bipolar leads recorded from the body surface of three fish species (Cyprinus carpio, Oreochromis niloticus and Pagrus major) in fresh or sea-water

1. ECGs were recorded using five bipolar leads from the body surface of porgy Pagrus major and tilapia Oreochromis niloticus in fresh or sea-water, or held on a dry towel. 2. The maximum QRS amplitude was detected in lead V in both species being 54 +/- 25 microV in porgy and 241 +/- 78 microV in tilapia, respectively, when the fish were held on the dry towel. 3. Clear ECG waves could not be obtained from porgy in sea-water because of the porgy's small cardiac potential and leakage of the potential. However, clear ECG waves could be obtained in sea-water from the body surface of tilapia, with the average QRS amplitude being 35 +/- 8 microV. 4. The mean electrical P and QRS axes in tilapia were directed toward almost the same direction (frontal downward), whereas both P and QRS axes in most carp were in opposite directions. In porgy, the relationship between the P and QRS axes could not be identified due to the smaller amplitude of the P wave.     

Comparison of tyrosine phosphorylation of proteins by membrane fractions from mouse liver, Ehrlich ascites tumor and MH134 hepatoma

When membrane fractions from mouse liver, Ehrlich ascites tumor and MH134 hepatoma were incubated with [gamma-32P]ATP at 0 degree C in the presence of MnCl2, ZnCl2 and NaVO3, proteins were phosphorylated on tyrosines to a larger extent in liver membranes than in tumor membranes. Separation of labelled proteins by SDS-gel electrophoresis showed phosphorylated alkali-resistant bands of 170, 140, 130, 80, 56, 53 and 46 kDa proteins in Ehrlich ascites tumor membranes; liver membranes exhibited more strongly phosphorylated bands of 170, 56, 53 and 46 kDa proteins. Epidermal growth factor stimulated the tyrosine phosphorylation of only a 170 kDa protein, which was more significant in liver membranes. Liver membranes exhibited slightly higher levels of tyrosine protein kinase activity compared to tumor membranes.     

Intestinal Resistance in the Experimental Enteric Infection of Mice with a Mouse Adenovirus

Investigation was made on the process of enteric infection with mouse adenovirus strain K87 in inbred DK1 mice and the intestinal resistance acquired through infection. The cells containing viral antigens were enumerated in most parts of the infected intestinal tract by a fluorescent antibody technique, and the infectivity titer of the virus in each part was examined in mouse kidney tissue culture. The virus was observed to grow in 3~14 days (sometimos 3~21 days) after oral challenge, and infectivity titers reached their peak after 7~14 days, when a number of viral antigen-containing cells and cells with nuclear inclusions were detected. In the mice rechallenged 28 days after the initial challenge, the virus did not grow, and no viral antigen-containing cells were found. From these results it was concluded that the main sites where the virus grows in mice are the cells which are scattered in the epithelial layer of the mucous membrane of the small intestine, and which seem to be the usual epithelial cells and not Paneth's or goblet cells. As for intestinal resistance, experiments with inactivated vaccine and with passive transfer of serum-antibodies were performed in order to find out whether neutralizing antibodies in the serum had any influence on the growth of virus in the intestinal wall, and no influences were indicated. Eighteen days or more after challenge, K87 virus-neutralizing substances were detected in the intestinal wall and in the intestinal contents of the infected mice, but not in the serum-transferred mice, though both groups of mice had equal levels of serum antibodies. The substance continued to be found until 15 weeks after challenge in the intestinal contents, and until later than 34 weeks in the intestinal walls. The nature and the possible role of the substance is discussed, but actual data will be reported in subsequent papers.