Dopamine-β-Hydroxylase activity in serum of developing rats

Summary After birth, the activity of dopamine--hydroxylase in rat serum increased up to 14 days maximal level and decreased gradully to reach a low level at 42 days which was about 14% of the activity of maximal activity at 14 days.     

Influence of the structure of theN-terminal extremity ofα-MSH on the melanophore stimulating activity of this hormone

Zusammenfassung Drei strukturelle Analoge des-MSH wurden synthetisiert und auf ihre Melanophoren-stimulierende Wirksamkeit untersucht. Für das Auftreten einer ausgeprägten biologischen Aktivität scheint die Anwesenheit einerN-Acetyl-Gruppe an dem Aminoende der Peptidkette wichtiger zu sein als das Vorhandensein der zwei ersten amino-endständigen Aminosäurereste der-MSH-Kette.     

The structure of human interferon-β: implications for activity

Interferons (IFNs) are potent extracellular protein mediators of host defence and homoeostasis. This article reviews the structure of human IFN-β (HuIFN-β), in particular in relation to its activity. The recently determined crystal structure of HuIFN-β provides a framework for understanding of the mechanism of differentiation of type I IFNs by their common receptor. Insights are generated by comparison with the structures of other type I IFNs and from the interpretation of existing mutagenesis data. The details of the observed carbohydrate structure, together with biochemical data, implicate the glycosylation of HuIFN-β, which is uncommon among type I IFNs, as an important factor in the solubility, stability and, consequently, activity of the protein. Finally, these structural implications are discussed in the context of the clinical use of HuIFN-β. Received 12 June 1998; received after revision 16 July 1998; accepted 16 July 1998     

Does the moon influence the predatory activity of mites?

Periodicity in predatory activity was observed in overwintered females ofTyphlodromus pyri Scheuten (Acari: Phytoseiidae). Chronobiometrical analysis revealed that an approximately circabiseptan (about-14-day) rhythm is statistically significant, with a striking depression around the full moon.     

Proteolytic control of TGF-β co-receptor activity by BMP-1/tolloid-like proteases revealed by quantitative iTRAQ proteomics

The metalloproteinase BMP-1 (bone morphogenetic protein-1) plays a major role in the control of extracellular matrix (ECM) assembly and growth factor activation. Most of the growth factors activated by BMP-1 are members of the TGF-β superfamily known to regulate multiple biological processes including embryonic development, wound healing, inflammation and tumor progression. In this study, we used an iTRAQ (isobaric tags for relative and absolute quantification)-based quantitative proteomic approach to reveal the release of proteolytic fragments from the cell surface or the ECM by BMP-1. Thirty-eight extracellular proteins were found in significantly higher or lower amounts in the conditioned medium of HT1080 cells overexpressing BMP-1 and thus, could be considered as candidate substrates. Strikingly, three of these new candidates (betaglycan, CD109 and neuropilin-1) were TGF-β co-receptors, also acting as antagonists when released from the cell surface, and were chosen for further substrate validation. Betaglycan and CD109 proved to be directly cleaved by BMP-1 and the corresponding cleavage sites were extensively characterized using a new mass spectrometry approach. Furthermore, we could show that the ability of betaglycan and CD109 to interact with TGF-β was altered after cleavage by BMP-1, leading to increased and prolonged SMAD2 phosphorylation in BMP-1-overexpressing cells. Betaglycan processing was also observed in primary corneal keratocytes, indicating a general and novel mechanism by which BMP-1 directly affects signaling by controlling TGF-β co-receptor activity. The proteomic data have been submitted to ProteomeXchange with the identifier PXD000786 and doi: 10.6019/PXD000786.     

Changes in dopamineβ-hydroxylase activity of monkey plasma with age

Summary Plasma dopamine -hydroxylase activity of Japanese monkeys (Macaca fuscata fuscata) increased with age, and the developmental changes were similar to those of human beings. However, the adult level plasma DBH activity of various monkey species was much lower than that of human beings.We thank Dr.K. Nozawa, Dr.O. Takenaka and Mr.T. Shotake (Primate Research Institute, Kyoto University) for their help in collecting monkey blood samples.     

Variation of glutamate decarboxylase activity andγ-amino butyric acid content of wheat embryos during ripening of seeds

Summary GAD activity and -ABA content of wheat embryos at 7 ripening stages were verified with the aim of studying the metabolic activity of embryo during dehydration and quiescence of caryopsis. Data showed that in the early stage of ripening GAD activity is very low, increases rapidly at dough-stage, remaining constant up to waxystage, and decreases in the last fully-ripe embryos. -ABA content appears to be roughly parallel to the variations of GAD activity.This work was supported by a grant from the Consiglio Nazionale delle Ricerche.     

Effect of hormones and cyclic AMP on γ-glutamyltranspeptidase activity of rat mammary gland explants

Summary -Glutamyl transpeptidase activity was assayed in midpregnant rat mammary gland explants at 14, 22 and 38 h, in the presence and absence of insulin, prolactin and corticosterone. With these 3 hormones the explants attained the characteristics of a secretory gland after 22 h of tissue culture, at which time the enzyme exhibited its maximal activity. The addition of dibutyryl cyclic AMP in the presence of the 3 hormones produced a significant increase in enzyme activity, which was maximal with a 1 mM concentration of the cyclic nucleotide. A similar effect was observed when theophylline or theophylline plus dibutyryl cyclic AMP were added to the culture medium.This work was supported by grant B1138-8333 from the Departamento de Desarrollo de la Investigación, Universidad de Chile.     

Elevation of plasma dopamine-β-hydroxylase activity during insulin-induced hypoglycemia in man

Résumé Nous avons étudié l'activité de la dopamine--hydroxylase du plasma humain. Elle a été remarquablement accure par l'administration de grandes quantités d'insuline. Les corrélations entre cette activité et celle des systèmes nerveux sympathiques sont également discutées.     

Influence of cyproterone acetate on the activity ofβ-glucuronidase in the hypothalamus and cerebral cortex of the male mouse

Summary Daily s.c. injections of cyproterone acetate greatly decrease the protein content and-glucuronidase activity in the mouse hypothalamus. These effects are reversible and the recovery capacity of the animal seems to be inversely related to the duration of antiandrogenic treatment.Financial aid was given by CNR (finalized project Biologia della Riproduzione) and Ministry of Education. Thanks are also due to Prof. G. Chieffi for suggestions and to Mr R. Auriemma for maintenance of experimental animals.     

Estrogenic activity and steric hindrance to coplanarity of alkyl substituted 4,4′-dimethoxystilbenes

Zusammenfassung Für eine Reihe Methyl- bzw. Äthylsubstituierter 4,4-Dimethoxystilbene ist die relative östrogene Wirksamkeit ermittelt worden. Dabei ergab sich eine Parallele zwischen der Aktivität und dem Grad der sterischen Hinderung, welche die Koplanarität der beiden Phenylkerne aufhebt. Maximale Wirksamkeit konnte auch mit Methyl-, nicht nur mit Äthylgruppen an der Doppelbindung erreicht werden.

---

---

The contents of this paper have been reported in more detail in the thesis ofW. H. Laarhoven, Leiden (1959).     

β-alanine and α-L-alanine inhibit the exploratory activity of spontaneously hypertensive rats

Summary 1% -alanine and -L-alanine, when given for 7 days as the only drinking fluid, inhibited the exploratory activity of adult male spontaneously-hypertensive rats (SHR)_but not that of the normotensive Wistar-Kyoto rats (WKR). -Alanine decreased the taurine level in the liver of both strains and in the platelets of SHR. -Alanine decreased the taurine level in the liver of WKR and in the platelets of SHR.This study was supported by the Sigrid Jusélius Foundation.     

Increase in cystathionine β-synthase activity in the liver of rats treated withl-ethionine

Résumé Une seule injection d'éthionine (400 mg/kg) provoque une augmentation significative de l'activité de la cystathionine -synthase du foie de rat. La méthionine empêche l'effect de l'éthionine, tandis que l'actinomycine D, le cycloheximide, la méthionine sulfoximine, la méthionine sulfona et l'ATP ne le modifient pas. In vitro, l'éthionine n'a aucune influence sur l'activité de la cystathionine synthase hépatique.

---

---

This work was supported by the Serbian Medical Research Foundation.     

Effects of N2, O2′-dibutyril cyclic GMP on the nucleoside phosphotransferase activity of the retina of the chick embryos

Summary In the retina of the chick embryo, 2 different forms of nucleoside phosphotransferase take part in the phosphorylation of thymidine. One is an unstable form with higher molecular weight. The other with lower m. wt is a stable form. This paper shows that N², O²-dibutyril cyclic GMP causes a marked decrement of the activity of the unstable nucleoside phosphotransferase.     

Cell surface protease activity of human lymphocytes; its inhibition by α 1-antitrypsin

Summary Using isotopically-labelled casein as substrate, a surface-associated protease activity was demonstrated on human peripheral blood and tonsil lymphocytes. It was greater in T-depleted than in T-enriched suspensions. It could be inhibited by 1-antitrypsin purified from human serum.This work was supported by the University Lyon I (Unité de Biologie Humaine).     

Selective activity of morphine on the ‘EEG arousal reaction’ to painful stimuli

Résumé L'action de la morphine sur l'activité électrique cérébrale a été étudiée sur le lapin ni anesthésié ni curarisé. La réaction d'arrêt, qui se traduit par une désynchronisation du tracé EEG, consécutive à un stimulus douloureux (stimulation du nerf sciatique, pincement de l'oreille) est abolie par des doses de morphine qui n'influencent pas les modifications analogues du tracé EEG provoquées par les stimulations sensitives ou sensorielles (stimulation olfactive, acoustique ou tactile).Une telle spécificité, qui n'apparaît pas dans le cas de la scopolamine et des barbituriques (Pentobarbital), peut être mise en rapport avec l'action analgésique caractéristique de la morphine.     

Amyloid β-induced FOXRED2 mediates neuronal cell death via inhibition of proteasome activity

Proteasome inhibition has been regarded as one of the mediators of Aβ neurotoxicity. In this study, we found that FOXRED2, a novel endoplasmic reticulum (ER) residential protein, is highly up-regulated by Aβ in rat cortical neurons and SH-SY5Y cells. Over-expression of FOXRED2 inhibits proteasome activity in the microsomal fractions containing ER and interferes with proteasome assembly, as evidenced by gel filtration and native gel electrophoresis analysis. In contrast, reduced expression of FOXRED2 rescues Aβ-induced inhibition of proteasome activity. FOXRED2 is an unstable protein with two degradation boxes and one KEN box, and its N-terminal oxidoreductase domain is required for proteasome inhibition. Ectopic expression of FOXRED2 induces ER stress-mediated cell death via caspase-12, which is inhibited by Salubrinal. Further, down-regulation of FOXRED2 expression attenuates Aβ-induced cell death and the ER stress response. These results suggest that up-regulated FOXRED2 inhibits proteasome activity by interfering with 26S proteasome assembly to contribute to Aβ neurotoxicity via an ER stress response.