Adrenal corticosteroidogenesis after removal of ventral prostate gland

Summary Removal of the ventral prostate gland in adult male rats causes an increase in adrenal weight, and stimulation of adrenal ⁵-3-hydroxysteroid dehydrogenase activity along with elevation of serum levels of corticosterone and prolactin.     

Differential expression and dosage compensation of theα-amylase gene inDrosphila miranda

Summary The-amylase gene ofDrosophila miranda is located on the X²-and on the neo-Y-chromosome, both developing sex chromosomes. Crosses between strains carrying different electrophoretically distinguishable alleles of the-amylase gene were performed. Females of the F₁ offspring showed the expected heterozygosity, while the males proved to be hemizygous for this locus. Only the gene on the X²-chromosome is expressed, whereas the corresponding gene on the neo-Y-chromosome is not. Estimates of the-amylase activity in crude homogenates of male and female flies suggest strongly that the-amylase gene is dosage compensated inD. miranda. In contrast to this situation, in all otherDrosophila species the-amylase allele is autosomal and hence not dosage compensated.Acknowledgments. We would like to thank Betty C. Moore, for the kind supply ofD. miranda strains. For the help and advice in the electrophoretic separation of the-amylase variants we are indebted to Dr W. Pinsker. This work was supported by a grant from the Fonds zur Förderung der wissenschaftlichen Forschung, P5413 (Austria).     

Characterization of 17β-estradiol 3-(β-D-glucopyranoside) and 17-(α-D-glucopyranoside) as the metabolites of 17β-estradiol in the cultured ovaries of the silkworm,Bombyx mori

Summary The structures of the metabolites formed upon incubation of 17-estradiol with the ovaries of silkworm,Bombyx mori, have been determined as 17-estradiol 3-(-D-glucopyranoside) (1) and 17-(-D-glucopyranoside) (2) by spectroscopic means.     

Evidence for a role of IFN γ in control ofListeria monocytogenes in T cell deficient mice

Summary The role of interferon (IFN) in controlling chronic infections ofListeria monocytogenes (Listeria) was studied in athymic C57BL/6nu/nu mice, and by treating thymectomized C57BL/6 +/+ mice with monoclonal rat CD4 and CD8-specific monoclonal antibodies (Mab). Mice treated with a combination of the two T cell subset antibodies were similar to athymic, nude mice in being able to contol Listeria infection, keeping the titers below 3–5 log₁₀ bacteria per organ, but they could not eliminate them completely. Treatment with antibodies to IFN of nude or CD4⁺ + CD8⁺-T cell-depleted mice suffering from chronic Listeria infection caused a marked increase of Listeria titers, in liver and spleen. This result implies a role of IFN in maintaining anti-Listeria resistance in mice lacking mature T cells.     

Hydra vulgaris ω10-lipoxygenase is used in vivo to synthesize new α-linolenic acid metabolites

Previous studies conducted in cytosolic extracts of the freshwater hydrozoanHydra vulgaris led to the finding of an abundant 11(R)-lipoxygenase catalyzing the peroxidation of polyunsaturated fatty acid (PUFAs) on the tenth carbon atom from the aliphatic end (10 peroxidation). Here we describe experiments aimed at identifying the actual metabolites generated in vivo by such enzymic activity. Homogenates ofH. vulgaris polyps were analyzed by HPLC. This showed the presence of three major components chromatographically identical to three metabolites obtained when incubating the homogenates with exogenous -linolenic acid (-LA). The presence, in extracts of polyps prelabelled with [¹⁴C]--linolenic acid, of radioactive metabolites displaying the same chromatographic properties, substantiated the hypothesis that the natural products isolated in vivo are derived from -LA. Gas chromatographic analyses revealed that this was the most abundant PUFA in both free and phosphoglyceride-bound fatty acid pools. [¹H]-NMR analysis of the endogenous substances, carried out in comparison with products obtained from exogenously incubated -LA, indicated that their structures were those of 9-hydroxy-, 9-hydroperoxy- and 9-keto-octadeca-10E-12Z-15Z-trienoic acids (9--HOTrE,-HPOTrE and-KOTrE).Hydra homogenates transformed 9--HPOTrE partly into 9--HOTrE and partly into 9--KOTrE. Chiral phase HPLC conducted on 9--HOTrE established that this metabolite was composed mostly of theR anantiomer. These observations, and the finding that the presence of exogenous arachidonic acid in incubated homogenates significantly reduces the production of -LA metabolites, provide strong evidence that these compounds are produced by an enzymic activity identical to the previously-describedH. vulgaris (R)-10-lipoxygenase. Further experiments suggested that -LA, acting as the native substrate for this enzyme, is mainly esterified on the 2 position ofHydra phosphoglycerides, and that the production of the -LA metabolites described here for the first time from natural sources, can be potentially enhanced in vivo by stimuli activating phospholipase A₂.     

The biotransformation of tritiated 3-dehydroecdysone by crayfish,Procambarus clarkii

The injection of 3-dehydroecdysone (3dhE, 5 /g), the major ecdysteroid secreted by the Y-organ of crayfishProcambarus clarkii, resulted in apolysis within about 5 days. The hormonal response at the molecular level was investigated by injection of the radio-labeled compound; within 3 h of injection of [³H]3dhE, most radio-isotope was found in the extracted epidermal tissues and identified as ecdysone, 20-hydroxyecdysone (20E), and their 3-hydroxy epimers. The biotransformation was undoubtedly performed in the peripheral area of the Y-organ. Cleavage of the polar conjugates, using an enzyme fromHelix pomatia, gave all of the above ecdysteroids including 3dhE. It was also found that the biosynthetic site of 3dhE was different from that of ecdysone at the subcellular level of the Y-organ.     

Kelletinin I and kelletinin A from the marine molluscBuccinulum corneum are inhibitors of eukaryotic DNA polymeraseα

Summary The inhibitory effect of esters of p-hydroxybenzoic acid (kelletinins I and A), extracted from the marine gastropodBuccinulum corneum, have been tested on eukaryotic and prokaryotic enzymes of DNA metabolism such as DNA polymerases and , DNA polymerase I, Exo III, pancreatic DNAse I, micrococcal DNAse andE. coli RNA polymerase. Kelletinin I and kelletinin A inhibit preferentially DNA polymerase. The inhibitory effect of kelletinin I involves the hydroxyl group of p-hydroxybenzoic acid.     

Anti-bovineβ-lactoglobulin antibodies react with a human lactoferrin fragment and bovineβ-lactoglobulin present in human milk

Human milk samples react against anti-bovine-lactoglobulin rabbit antibodies, as measured by a competitive radioimmunoassay. Immunoreactivity was positive even in milk from mothers consuming a diet free of cow's milk. An increase with a diet rich in cow's milk proteins was detected by immunoelectrophoresis. The human milk fraction cross-reacting with anti-bovine-lactoglobulin antibodies corresponds to the 20 kDa fragment from the N-terminal end of human lactoferrin. Three regions of this fragment exhibit sequence homology with a sequence contained in cow's-lactoglobulin (between residues 124 and 141).     

Muscle LIM protein promotes expression of the acetylcholine receptor <Emphasis Type="Italic">γ</Emphasis>-subunit gene cooperatively with the myogenin-E12 complex

Muscle LIM protein (MLP, also referred to as CRP3) is a muscle-specific LIM-only protein, which consists of two LIM motifs. MLP functions as a positive regulator during myogenesis. Here we report that MLP serves as a cofactor regulating the expression of the nicotinic acetylcholine receptor (AChR) -subunit gene in skeletal muscle cells. We found that MLP promoted the expression of the AChR -subunit gene in C2C12 myotubes, but not in C2C12 myoblasts or NIH3T3 fibroblasts. Furthermore, we showed that MLP interacted with myogenin in vivo and enhanced the binding ability of the myogenin-E12 heterodimer to the E boxes in the AChR -subunit gene promoter. Together, these results suggest that MLP promotes the specific expression of the AChR -subunit gene cooperatively with the myogenin-E12 complex during myogenesis.Received 17 May 2004; received after revision 22 July 2004; accepted 26 July 2004     

Selective protection of cells against X-irradiation. Isoproterenol protects only those cells that possesβ-adrenoreceptors

Summary In mixed culture of Chinese hamster fibroblatst, clone 431, and transformed murine L fibroblasts, clone B-82, isoproterenol was found to protect only 431 cells against ionizing radiation. It was shown that 431 cells, in contrast to B-82 cells, possess-adrenoreceptors, and the radioprotective effect of isoproterenol can be realized only if this agent interacts with-adrenoreceptors coupled with the cAMP system. Since malignization often causes the disappearance of-adrenergic and other hormone receptors, the combined culturing and irradiation of the cells studied can be regarded as a model of the growth of malignant cells (B-82) among normal tissue cells (431 cells) under conditions of radiation therapy. A possibility of selective protection against radiation damage of normal tissue cells, with retention of the former radiosensitivity of tumor cells, is discussed.     

BlaB,a protein involved in the regulation of <Emphasis Type="Italic">Streptomyces cacaoi</Emphasis> β-lactamases,is a penicillin-binding protein

Streptomyces cacaoi -lactamase genes are controlled by two regulators named blaA and blaB. Whereas BlaA has been identified as a LysR-type activator, the function of BlaB is still unknown. Its primary structure is similar to that of the serine penicillin-recognizing enzymes (PREs). Indeed, the SXXK and KTG motifs are perfectly conserved in BlaB, whereas the common SXN element found in PREs is replaced by a SDG motif. Site-directed mutations were introduced in these motifs and they all disturb -lactamase regulation. A water-soluble form of BlaB was also overexpressed in the Streptomyces lividans TK24 cytoplasm and purified. To elucidate the activity of BlaB, several compounds recognized by PREs were tested. BlaB could be acylated by some of them, and it can therefore be considered as a penicillin-binding protein. BlaB is devoid of -lactamase, D-aminopeptidase, DD-carboxypeptidase or thiolesterase activity.Received 13 January 2003; received after revision 9 April 2003; accepted 11 April 2003     

γ-Glutamyl-transpeptidase in lymphatic tissues ofMastomys natalensis during an infection withAcanthocheilonema viteae

Summary DuringAcanthocheilonema viteae infection, the specific activity of -glutamyltranspeptidase (-GT) increased in peritoneal exudate cells and bone marrow and decreased in lymphnodes ofMastomys natalensis throughout the course of infection. However, though there was an increase in specific activity of -GT in thymus and spleen during the prepatent phase ofA. viteae infection, the level either returned to normal or decreased during the latent phase of infection. A close correlation was observed between the host's immune status duringA. viteae infection and the level of -GT in lymphoid tissues.Communication No. 4535 from Central Drug Research Institute, Lucknow.     

Detection of pyrimidine 5′-nucleotidase deficiency using1H-or31P-nuclear magnetic resonance

Summary We describe here a further Japanese family with pyrimidine 5-nucleotidase (P5N) deficiency diagnosed using a nuclear magnetic resonance (NMR) spectrum, in Kumamoto prefecture where two families having the disease have been reported before. The specific spectra in¹H-NMR of P5N deficient erythrocytes were due to three methyl protons of CDP-choline at 3.22 ppm and to H-2, H-8 and ribose-1 of pyrimidine nucleotide phosphate(s) in the lower fields (at 5.82 and 8.00 ppm). The other specificities in³¹P-NMR spectra were due to CDP-choline, CDP-ethanolamine and UDP-glucose. Those spectra were not detected in other types of hemolytic anemia.     

Evidence for the extranuclear localization of thymosins in thymus

A new radioimmunoassay has been developed for thymosin ₄ by generating rabbit polyclonal antibodies against the synthetic N-terminal peptide fragment 1–15 coupled to KLH. The synthetic analogue [Tyr¹²]-thymosin ₄ (1–15) was used as tracer. This radioimmunoassay, with a useful range of 10–1000 pmoles, showed cross-reactivity with the second homologous -thymosin of man and rat (thymosin ₁₀) but not of calf (thymosin ₉). This radioimmunoassay, together with an improved radioimmunoassay for the N-terminus of parathymosin , was employed for the measurement of the levels of thymosin ₄ and parathymosin in nuclear and extranuclear extracts of calf thymus. The bulk of these polypeptides was found in the extranuclear material whereas only traces were observed in the nuclear environment, which indicates the extranuclear localisation of - and -thymosins.     

Horizontal gene transfer from Eukarya to Bacteria and domain shuffling: the α-amylase model

-Amylases are present in all kingdoms of the living world. Despite strong conservation of the tertiary structure, only a few amino acids are conserved in interkingdom comparisons. Animal -amylases are characterized by several typical motifs and biochemical properties. A few cases of such -amylases have been previously reported in some eubacterial species. We screened the bacterial genomes available in the sequence databases for new occurrences of animal-like -amylases. Three novel cases were found, which belong to unrelated bacterial phyla: Chloroflexus aurantiacus, Microbulbifer degradans, and Thermobifida fusca. All the animal-like -amylases in Bacteria probably result from repeated horizontal gene transfer from animals. The M. degradans genome also contains bacterial-type and plant-type -amylases in addition to the animal-type one. Thus, this species exhibits -amylases of animal, plant, and bacterial origins. Moreover, the similarities in the extra C-terminal domains (different from both the -amylase domain C and the starch-binding domain), when present, also suggest interkingdom as well as intragenomic shuffling.Received 17 October 2003; accepted 6 November 2003     

Effect of acute administration of Δ1-tetrahydrocannabinol on β-endorphin levels in plasma and brain tissue of the rat

Summary Acute treatment with ¹-tetrahydrocannabinol (¹-THC) elevated the concentration of -endorphin-like immunoreactivity (-ELIR) in plasma and in the hypothalamus, but not in the hippocampus of rats habituated to the injection procedure. These effects were not obtained with the psychotropically inert analog of (¹-THC), cannabidiol. In animals that had not been habituated to the injection procedure, placebo treatment induced a decrease in hippocampal -ELIR.The authors acknowledge the skillful technical assistance of Mrs Willeke Logtenberg.     

Benzamide potentiation of behavioral apomorphine-induced effects; mechanism involved

Summary A new N-pyridinyl benzamide was found to potentiate strongly the effects of apomorphine on the motility of reserpinized mice and on circling behavior. Since dopaminergic agonist activity could not account for this potentiation, involvement of-adrenergic agonist activity provided the only consistent explanation.Acknowledgments. We wish to thank Mr A. Decoodt for his excellent technical assistance and the Laboratoire de Chimie Therapeutique (Prof. Le Baut), Université de Nantes, for providing samples of N-PCB.     

Discovery of novel avermectins with unprecedented insecticidal activity

Summary A new class of insecticidal and antiparasitic agents, 4-amino-4-deoxy avermectins, has been developed by chemical modification of avermectin B₁. The most effective of these compounds are 1500-fold more potent than avermectin B₁ (abamectin) against the beet armywormSpodoptera exigua and show similar potency against other lepidopteran larvae.     

Oviposition stimulants of aCitrus-feeding swallowtail butterfly,Papilio xuthus L

Summary A methanolic extract ofCitrus unshiu induces oviposition by females of aCitrus-feeding swallowtail butterfly,Papilio xuthus L. The chemical factors responsible for stimulating oviposition were isolated and characterized as 5-hydroxy-N-methyltryptamine, adenosine, vicenin-2, narirutin, hesperidin and rutin. An artificial blend of these six components elicited significant oviposition behavior, apparently identical to that induced by contact with intactCitrus leaves.     

Effects of pertussis toxin onα 1-agonist-mediated phosphatidylinositide turnover and myocardial cell hypertrophy in neonatal rat ventricular myocytes

Summary In neonatal rat ventricular myocytes pretreatment with pertussis toxin did not affect 1 M (–)-norepinephrine stimulation of inositol phosphates or myocardial cell hypertrophy as measured either by protein radiolabelling or by myocardial cell protein content. Thus guanine nucleotide protein (s) ADP-ribosylated by pertussis toxin do not play a role in two ₁-adrenoceptor-mediated processes, phosphatidylinositide turnover and induction of myocardial cell hypertrophy.