Dopamine-β-hydroxylase-, neurotensin-, substance P-, vasoactive intestinal polypeptide- and enkephalin-immunohistochemistry of paravertebral and prevertebral ganglia in the cat

Summary Para and prevertebral ganglia of the cat were investigated for immunoreactivity (IR) against neurotensin (NT), vasoactive intestinal polypeptide (VIP), substance P (SP) and enkephalin (ENK). Dopamine--hydroxylase- (DBH)-IR was studied in consecutive sections to correlate the distribution of noradrenergic/adrenergic neurons with that of peptidergic nerve fibres and cells.In paravertebral (cervical and thoracic) ganglia, NT-IR or ENK-IR nerve fibres were seen in areas in which DBH-IR fibre networks also occurred. NT-IR varicosities were often in close contact with perikarya of principal ganglionic cells on which DBH-IR varicosities also terminated. Such an association was rarely seen between ENK-IR and DBH-IR fibre baskets. NT-IR and ENK-IR fibre baskets were not found to occur around the same principal ganglionic cell. The distribution of VIP-IR and SP-IR nerve fibres did not coincide with that of DBH-IR fibres.In prevertebral ganglia (celiac-superior mesenteric and inferior mesenteric) DBH-IR or VIP-IR varicosities surrounded the majority of principal ganglionic neurons. ENK-IR or SP-IR fibres were closely associated with only a minority of the neurons; NT-IR networks were rather sparse. Some principal neurons were approached by DBH-IR fibres and by different peptide-IR fibres.In paravertebral ganglia some principal ganglionic cells contained VIP-IR, a few of which were also surrounded by NT-IR varicosities. VIP-IR perikarya in prevertebral ganglia were extremely rare. No NT-IR, SP-IR or ENK-IR principal ganglionic cells were found.Glomus-like paraganglionic cell clusters in paravertebral and prevertebral ganglia exhibited DBH-IR cell bodies. Moreover, the clusters also contained ENK-IR or SP-IR cells. NT-IR varicosities were observed adjacent to clustered paraganglionic cells. Only few singly located paraganglionic cells were NT-IR or ENK-IR.The differential distribution of peptide-IR nerve endings in the investigated ganglia suggests a regulation of impulse transmission that seems to be related to the target organs.Fellow of the Heisenberg foundationSupported by the DFG, grants He 919/5, Re 520/1-2, and SFB 90 Carvas, Heidelberg     

Inositol 1,4,5-triphosphate phosphatase activity in membranes isolated from amphibian skeletal muscle [corrected

The hydrolysis of [3H]inositol 1,4,5-trisphosphate by a soluble fraction and by isolated transverse tubule and sarcoplasmic reticulum membranes from frog skeletal muscle was studied. Transverse tubule membranes displayed rates of hydrolysis several-fold higher than those of sacroplasmic reticulum and soluble fraction; Km and Vmax were 25.2 microM and 44.1 nmol/mg/min, respectively. Transverse tubule membranes sequentially hydrolyzed inositol trisphosphate to inositol bisphosphate, inositol 1-phosphate and inositol, indicating that these membranes have inositol bis- and monophosphatases in addition to inositol trisphosphatase.     

Reversed-phase liquid chromatographic investigation of UV-absorbing low-molecular-weight compounds in saliva

The reversed-phase mode of high-performance liquid chromatography was used to determine the intra- and inter-individual levels of UV-absorbing low-molecular-weight compounds in saliva. Many of the compounds known to occur in serum were also found in saliva; however, concentrations in saliva are lower. Both the intra- and inter-individual levels of these compounds vary significantly; in most cases, the inter-individual variance is 2–3 times the intra-individual variance.

Caffeine and its metabolites in saliva are also reported. A greater number of metabolites were found in the saliva of habitual coffee drinkers. After caffeine was administered orally, paraxanthine, theobromine, theophylline, 1-methylxanthine, and 1-methyluric acid were found in the saliva of an individual who did not drink coffee regularly. In this subject, the serum half-life for caffeine was 3.49 h and the saliva half-life was 3.27 h. The half-life of caffeine in an habitual coffee drinker who had refrained from caffeine products for four days was 4.39 h.     

Comparison of high-performance liquid chromatographic serum profiles of humans and dogs

The sera of 30 healthy male beagles were analyzed by reversed-phase high-performance liquid chromatography. The profiles were compared with those obtained from the sera of 30 healthy human donors. The chromatograms of each group were very reproducible; however, there were characteristic differences between the two groups. The compounds observed in both the human and canine profiles were identified as creatinine, uric acid, tyrosine, hypoxanthine, xanthine, kynurenine, inosine and tryptophan. Compounds present only in the canine profiles were identified as cytindine, riboflavin and 5-methylcytidine. Compounds present only in the human profiles include uridine, guanosine, hippuric acid and the dietary dependent compounds theobromine and caffeine. The compounds present in both human and canine sera were quantitated and compared statistically. The amounts of these compounds were very similar, except for uric acid.     

Genetic and biochemical characterization of D-arabinose dehydrogenase from Neurospora crassa.

D-Arabinose dehydrogenase has been purified to homogeneity from wild-type Neurospora crassa 74-A (FGSC 262) and from two colonial mutants, col-15a (FGSC 1391) and col-16a (FGSC 1349), found to contain more of the enzyme. The enzymes were characterized by measurement of several kinetic and physicochemical parameters. The enzymes were the same in all characteristics studied thus far. Immunological studied performed with enzyme preparations from the three strains showed antigenic identity and indicated that those colonial strains contain more normal enzyme, rather than the usual amount of an altered "improved" enzyme. Quantitation of the enzyme in crude extracts, performed by single radial immunodiffusion, showed that the colonial strains have twice the level of enzyme as the wild-type strain. Genetic characterization, performed by analysis of meiotic products, heterokaryosis, and reversions, indicated that the difference in D-arabinose dehydrogenase activity detected among the three strains is probably determined by one gene. The genetic control, structural or regulatory of this enzyme activity is different from that determining the morphological alterations exhibited by mutant strains carrying the col-15 or col-16 gene.     

Independent temporal expression of two N-substituted aminoacyl-tRNA hydrolases during the development of Artemia salina.

Encysted embryos of the crustacean Artemia salina contain an enzymatic activity which hydrolyzes N-acetylphenylalanyl-tRNA to N-acetylphenylalanine and tRNA. The enzyme apparently does not hydrolyze other free or N-substituted aminoacyl-tRNAs. The levels of this enzyme do not significantly change during embryonic and early larval development. In contrast, an unspecific hydrolase active on several N-substituted aminoacyl-tRNAs is practically absent in the encysted embryos and during embryogenesis and appears abruptly during larval development. The independent temporal expression of these two hydrolases during Artemia salina differentiation makes this organism siuitable for the study of the physiological role of these enzymes.     

Lipids of higher fungi. III. The fatty acids and 2-hydroxy fatty acids in some species of Basidiomycetes

Total fatty acids derived from 12 species of mushrooms were separated into fatty acid and 2-hydroxy fatty acid fractions (FA and HFA), and analyzed quantitatively. The HFA content varied from 0 to 22% of total fatty acids. The major fatty acids were 16:0, 18:0, 18:1, 18:2, and the major 2-hydroxy fatty acids were h16:0, h18:0, h22:0, h24:0. The predominant HFA in the mushrooms investigated had chain-lengths greater than 20 C-atoms, and were derived from sphingolipids — ceramides and cerebrosides.     

Binding of aminoacyl-tRNA to rat liver ribosomal proteins

Rat liver ribosome treatment with ethanol and 1 M NH₄Cl releases some 31–33 ribosomal proteins. This split protein fraction binds Phe-tRNA, Ac-Phe-tRNA, Met-tRNA_M and f-Met-tRNA_F in the absence of K⁺ and Mg⁺⁺ ions. When the split protein fraction is passed through Sephadex G-100 only six proteins are retained in the column: S10, S14, S15, S19, L35, and L36. The aminoacyl-tRNA binding activity of this protein fraction retained in the Sephadex G-100 column is similar to that of the total split protein fraction, suggesting that the above six proteins, or only some of them, are involved in the binding reaction.     

Effects of ricin on the ribosomal sites involved in the interaction of the elongation factors.

The effects of ricin on the different steps of the elongation cycle of protein synthesis in a rabbit reticulocyte cell-free system are studied in this paper. The toxin most probably acts by catalytically inactivating the ribosomes, since a single molecule of the toxin can inactivate 300 ribosomes for poly(U)-directed phenylalanine incorporation. The effect of the toxin on the ribosome is irreversible. Ricin specifically inhibits elongation-factor-1-dependent aminoacyl-tRNA binding to ribosomes but has no effect on the non-enzymic binding of aminoacyl-tRNA. Ricin also inhibits formation of the complex elongation-factor-2 - ribosome - nucleotide with GTP, GDP or GMP-P(CH2)P. However, the toxin has no effect on translocation. These apparently conflicting results are discussed in this study.