The biological function of rabbit blastocyst peptides (RBPs)

The inhibitory effect of rabbit blastocystic peptides (RBPs) on lymphocyte transformation was studied by the method of measuring the incorporation of 3H-thymidine into DNA. The results indicated that RBPs inhibited PHA-stimulated rat and human lymphocyte transformation in vitro. In the concentration ranging from 40 to 200 micrograms/2.5 ml, the inhibition was dose-dependent. No obvious inhibitory action was found with hCG (16-128) IU/2.5 ml), progesterone (250 ng-1 microgram/2.5 ml) and pregnant rabbit serum. It was further demonstrated that RBPs at a higher dosage (200 micrograms/ml) was inhibitory to PGF2 alpha secretion. On the other hand, the 3H-leucine incorporation of rabbit endometrium was enhanced by these peptides, and this action could be blocked by the addition of actidine.

Sequence characteristics of a gene in equine herpesvirus 1 homologous to glycoprotein H of herpes simplex virus

A gene in equine herpesvirus 1 (EHV-1, equine abortion virus) homologous to the glycoprotein H gene of herpes simplex virus (HSV) was identified and characterised by its nucleotide and derived amino acid sequence. The EHV-1 gH gene is located at 0.47-0.49 map units and contains an open reading frame capable of specifying a polypeptide of 848 amino acids, including N- and C-terminal hydrophobic domains consistent with signal and membrane anchor regions respectively, and 11 potential sites for N-glycosylation. Alignment of the amino acid sequence with those published for HSV gH, varicella zoster virus gpIII, Epstein Barr virus gp85 and human cytomegalovirus p86 shows similarity of the EHV gene with the 2 other alpha-herpesviruses over most of the polypeptide, but only the C-terminal half could be aligned for all 5 viruses. The identical positioning of 6 cysteine residues and a number of highly conserved amino acid motifs supports a common evolutionary origin of this gene and is consistent with its role as an essential glycoprotein of the herpesvirus family. An origin of replication is predicted to occur at approximately 300 nucleotides downstream of the EHV-1 gH coding region, on the basis of similarity to other herpesvirus origins.

[Histochemical study of carbohydrate residues in human aortic atherosclerotic lesions by application of lectins]

Carbohydrate residues of various cells in human normal aortic intima, fatty streaks and atherosclerotic plaques were studied with 10 kinds of biotinylated-lectins by immunohistochemical techniques in 10 cases. The results showed that: (1) The amount of carbohydrate residues increased along with the progressing of atherosclerotic lesions. (2) The cells in atherosclerotic lesions could be marked by more than one kind of lectins. (3) Decrease of carbohydrate residues on the endothelial membrane might be considered helpful to the formation of fatty streak.

Structural and functional analysis of the promoter region of the nerve growth factor gene

Molecular clones containing the NGF gene promoter regions and exons I were isolated from mouse and rat genomic libraries with synthetic oligonucleotide hybridization probes that corresponded to the 5' end of mouse submandibular gland NGF mRNA. The nucleotide sequences of the 5' flanking regions and exons I were determined and compared. There was 95% similarity in exons I and the adjacent promoter regions between mouse and rat sequences. Further upstream, the similarity decreased to 76%. Both mouse and rat promoter regions were only 33% similar to the presumptive human NGF gene promoter region. Upstream from the capsite of submandibular gland NGF mRNA as determined by an S1-nuclease protection assay, two promoter-like TATA-boxes were found at positions -28 and -49, resp., and two CAAT-like boxes at -379 and -546, resp. Both promoter regions contained a cluster of conserved CpG dinucleotide sequences in a GC-rich island whereas less conserved upstream regions contained only one CpG sequence. The promoter regions were fused to the human growth hormone gene reporter function. Transient expression in L929 cells yielded appropriate fusion mRNAs and secretion of hGH, demonstrating that the cloned promoters are functional.

Isolation and characterization of the specific peptides from rabbit blastocyst at peri-implantation stage with emphasis on their physiological significance relevant to the mechanism of implantation

The secretory materials from the uterine flushings of the pregnant, non-pregnant and pseudopregnant rabbits were analysed by the method of SDS-polyacrylamide gel electrophoresis. The results demonstrated that there are three specific peptides in the pregnant uterine flushings with molecular weights of 3000, 4500 and 6000. No correspondent peptides were found in non-pregnant and pseudopregnant uterine flushings. The peptides were also isolated and identified from the blastocystic fluid. At least 4 peaks of small peptides were shown by high pressure liquid chromatography. The range of their isoelectrophoretic points is between pH 4.0-5.5 Concavalin A (Con A) affinitive electrophoresis indicated that they are glycopeptides in nature. The LH-RH A is able to exert inhibitory effects on the synthesis of these peptides. Their possible physiological function has been discussed.

Electro-acupuncture markedly increases proenkephalin mRNA in rat striatum and pituitary

Electro-acupuncture (EA) has been found to increase enkephalin content in striatum, hypothalamus and cerebrospinal fluid. Further studies on rat striatum showed that the increase is accompanied by an elevation of enkephalin precursor and processed intermediate levels. In order to characterize the nature of these changes, we have measured the proenkephalin mRNA (PE-mRNA) level in rat striatum and pituitary by recombinant DNA technique. The PE-mRNA was hybridized with human proenkephalin cDNA using a dot-blot procedure. Rats receiving EA showed a 3-5-fold increase of PE-mRNA in striatum beginning at 1 h after the cessation of 30-min EA treatment and lasting 48 h at least. A 3-fold increase of PE-mRNA in pituitary was found immediately after the cessation of EA and a 5-6-fold increase at 1 or 24 h after the termination of EA.

Accumulation of radioiodinated 15-(p-iodophenyl)-6-tellurapentadecanoic acid in ischemic myocardium during acute coronary occlusion and reperfusion

The myocardial uptake of 15-(p-iodophenyl)-6- tellurapentadecanoic acid ( TPDA ) was studied in dogs during coronary occlusion and after reperfusion. In eight dogs with a 3 hour occlusion (Group A) with (n = 5) and without (n = 3) 30 minutes of reperfusion, iodine-125 TPDA uptake correlated well with microsphere myocardial blood flow over a wide range of flow levels (n = 111, r = 0.94). In six dogs with a 20 minute occlusion of the left anterior descending coronary artery and 1 hour of reperfusion (Group B), iodine-125 TPDA uptake correlated equally well with myocardial blood flow (n = 37, r = 0.90). There was no difference between the slopes of regression lines for Groups A and B, indicating no release from the myocardium of radioiodinated TPDA . Dual radiolabeling of TPDA was employed in five Group A animals by intravenous injection of iodine-125 TPDA during coronary occlusion and iodine-131 TPDA after reperfusion. In 63 myocardial samples, microsphere reperfusion flow and iodine-131 TPDA uptake were closely correlated (r = 0.91). As with monovalent cations, at myocardial flows higher than control flows, iodine-131 TPDA uptake was flow-limited. It is concluded that: 1) radioiodinated TPDA accurately reveals severely ischemic areas of myocardium without myocardial release of the radionuclide in coronary occlusions lasting 20 to 180 minutes and followed by reperfusion, and 2) double radiolabeled TPDA allows assessment of both occlusion and reperfusion flows. This compound may find an application in the measurement of infarct size and the evaluation of interventional therapies in acute myocardial infarction.