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The anabolic action of intermittent parathyroid hormone on cortical bone depends partly on its ability to induce nitric oxide‐mediated vasorelaxation in BALB/c mice
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S Gohin A Carriero C Chenu AA Pitsillides TR Arnett M Marenzana 《Cell biochemistry and function》2016,34(2):52-62
There is strong evidence that vasodilatory nitric oxide (NO) donors have anabolic effects on bone in humans. Parathyroid hormone (PTH), the only osteoanabolic drug currently approved, is also a vasodilator. We investigated whether the NO synthase inhibitor L‐NAME might alter the effect of PTH on bone by blocking its vasodilatory effect. BALB/c mice received 28 daily injections of PTH[1–34] (80 µg/kg/day) or L‐NAME (30 mg/kg/day), alone or in combination. Hindlimb blood perfusion was measured by laser Doppler imaging. Bone architecture, turnover and mechanical properties in the femur were analysed respectively by micro‐CT, histomorphometry and three‐point bending. PTH increased hindlimb blood flow by >30% within 10 min of injection (P < 0.001). Co‐treatment with L‐NAME blocked the action of PTH on blood flow, whereas L‐NAME alone had no effect. PTH treatment increased femoral cortical bone volume and formation rate by 20% and 110%, respectively (P < 0.001). PTH had no effect on trabecular bone volume in the femoral metaphysis although trabecular thickness and number were increased and decreased by 25%, respectively. Co‐treatment with L‐NAME restricted the PTH‐stimulated increase in cortical bone formation but had no clear‐cut effects in trabecular bone. Co‐treatment with L‐NAME did not affect the mechanical strength in femurs induced by iPTH. These results suggest that NO‐mediated vasorelaxation plays partly a role in the anabolic action of PTH on cortical bone. © 2016 The Authors. Cell Biochemistry and Function published by John Wiley & Sons, Ltd. 相似文献
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Nuclear gene trees and the phylogenetic relationships of the mangabeys (Primates: Papionini) 总被引:3,自引:1,他引:2
Phylogenetic relationships of mangabeys within the Old World monkey tribe
Papionini are inferred from analyses of nuclear DNA sequences from five
unlinked loci. The following conclusions are strongly supported, based on
congruence among trees derived for the five separate gene regions: (1)
mangabeys are polyphyletic within the Papionini; (2) Cercocebus is the
sister taxon to the genus Mandrillus; and (3) Lophocebus belongs to a clade
with Papio and Theropithecus, with Papio as its most likely sister taxon.
Morphologically based phylogenies positing mangabey monophyly were
evaluated by mapping the sequences for each locus on these trees. The data
seem to fit these trees poorly in both maximum-parsimony and likelihood
analyses. Incongruence among nuclear gene trees occurred in the
interrelationships among Lophocebus, Papio, and Theropithecus. Several
factors that may account for this incongruence are discussed, including
sampling error, random lineage sorting, and introgression.
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PPCMatrix: a PowerPC dotmatrix program to compare large genomic sequences against protein sequences 总被引:1,自引:0,他引:1
Summary : An interactive dotmatrix program for the MacOS was designed that
allows comparison of DNA to protein sequences using nested 3-frame
translations. Availability : Shareware, available at
http://copan.bioz.unibas.ch/software/ Contact : burglin@ubaclu. unibas.ch
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J S Strazanac C D Plaugher T R Petrice L Butler 《Journal of economic entomology》2001,94(5):1128-1134
Macrolepidopteran caterpillars collected in 1995 and 1996 in the Monongahela National forest, Pocahontas County, WV, and the George Washington National forest, Augusta County, VA, yielded 60 previously unreported tachinid host associations. Most associations were between native species, but the introduced polyphagous tachinid Compsilura concinnata (Meigen) produced eight new associations with native hosts. The tachinids collected were slightly broader in their host preferences than associated Braconidae and Ichneumonidae, illustrating their potential importance in regulating foliage-feeding macrolepidopteran populations in the region studied. The sample years reported herein are the pretreatment baseline portion of a long-term study on the effects of Lymantria dispar (L.) defoliation, efficacy of applied Bacillus thuringiensis variety kurstaki Berliner, and the natural occurrence of the L. dispar pathogen Entomophaga maimaiga Humber, Shimazu & Soper on nontarget organisms. 相似文献
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Anoplophora glabripennis (Motschulsky) (Coleoptera: Cerambycidae) is one of the most serious nonnative invasive forest insects discovered in North America in recent years. A. glabripennis is regulated by federal quarantines in the United States and Canada and is the subject of eradication programs that involve locating, cutting, and chipping all infested trees. Other control methods are needed to aid in eradication and to form an integrated management program in the event eradication fails. We conducted laboratory bioassays to determine the toxicity of two systemic insecticides, azadirachtin and imidacloprid, for potential control of A. glabripennis and the cottonwood borer, Plectrodera scalator (F.) (Coleoptera: Cerambycidae), a closely related native cerambycid. Larvae of both cerambycid species were fed artificial diet with dilutions of azadirachtin or imidacloprid for 14 wk. Both insecticides exhibited strong antifeedant effects and some toxicity against A. glabripennis and P. scalator larvae. For A. glabripennis, the highest larval mortality at the end of the bioassay was 60% for larvae fed artificial diet treated with azadirachtin (50 ppm) or imidacloprid (1.6 ppm). For P. scalator, the highest larval mortality at the end of the bioassay was 100% for larvae fed artificial diet treated with azadirachtin (50 ppm) or imidacloprid (160 ppm). At 14 wk, the LC50 values for P. scalator were 1.58 and 1.78 ppm for azadirachtin and imidacloprid, respectively. Larvae of both species gained weight when fed diet treated with formulation blanks (inert ingredients) or the water control but lost weight when fed diet treated with increasing concentrations of either azadirachtin or imidacloprid. In a separate experiment, A. glabripennis adults were fed maple twigs treated with high and low concentrations of imidacloprid. A. glabripennis adult mortality reached 100% after 13 d on twigs treated with 150 ppm imidacloprid and after 20 d on twigs treated with 15 ppm imidacloprid. There was no visible feeding by A. glabripennis adults on twigs treated at the higher imidacloprid rate, and feeding was significantly reduced for adults placed on twigs treated at the low imidacloprid rate compared with adults on untreated twigs. In summary, imidacloprid and azadirachtin had both antifeedant and toxic effects against A. glabripennis and P. scalator and have potential for use in management programs. Based on our results, the delivery of high and sustained insecticide concentrations will be needed to overcome the antifeedant effects and lengthy lethal time for both larvae and adults exposed to these insecticides. 相似文献
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Evolution of eutherian cytochrome c oxidase subunit II: heterogeneous rates of protein evolution and altered interaction with cytochrome c 总被引:3,自引:1,他引:2
Cytochrome c oxidase subunit II (COII), encoded by the mitochondrial
genome, exhibits one of the most heterogeneous rates of amino acid
replacement among placental mammals. Moreover, it has been demonstrated
that cytochrome c oxidase has undergone a structural change in higher
primates which has altered its physical interaction with cytochrome c. We
collected a large data set of COII sequences from several orders of mammals
with emphasis on primates, rodents, and artiodactyls. Using phylogenetic
hypotheses based on data independent of the COII gene, we demonstrated that
an increased number of amino acid replacements are concentrated among
higher primates. Incorporating approximate divergence dates derived from
the fossil record, we find that most of the change occurred independently
along the New World monkey lineage and in a rapid burst before apes and Old
World monkeys diverged. There is some evidence that Old World monkeys have
undergone a faster rate of nonsynonymous substitution than have apes. Rates
of substitution at four-fold degenerate sites in primates are relatively
homogeneous, indicating that the rate heterogeneity is restricted to
nondegenerate sites. Excluding the rate acceleration mentioned above,
primates, rodents, and artiodactyls have remarkably similar nonsynonymous
replacement rates. A different pattern is observed for transversions at
four-fold degenerate sites, for which rodents exhibit a higher rate of
replacement than do primates and artiodactyls. Finally, we hypothesize
specific amino acid replacements which may account for much of the
structural difference in cytochrome c oxidase between higher primates and
other mammals.
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