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91.
Insectivorous Mediterranean house geckos, Hemidactylus tursicus, are found in the field close to the burrows of calling male decorated crickets, Gryllodes supplicans. In playback experiments where adult geckos were presented with calls of these crickets or calls of frogs as controls, geckos exhibited positive phonotaxis to broadcast cricket calling song. This indicates that geckos orient to and approach male cricket calls, even though the crickets call from burrows where they are protected from the geckos. However, this behaviour enables the geckos to intercept and consume female crickets that also respond phonotactically to the cricket calls. Thus geckos act as ‘satellite predators’, a situation which may impose sex-biased mortality on female crickets. 相似文献
92.
What's new in lysozyme research? 总被引:49,自引:0,他引:49
The present review is focused on the main achievements realized in the lysozyme research field since the meeting held in 1972 to commemorate the fiftieth anniversary of the discovery of this enzyme. Despite of extensive structural, physico-chemical, crystallographic, genetic, immunological and evolutionary studies devoted to lysozymes, their biological role is still not exactly known. 相似文献
93.
94.
The reduction of cytochrome c by beef liver sulfite oxidase was found to be strongly inhibited by high ionic strength, indicating the importance of electrostatic interactions to the reaction. The reaction rates of sulfite oxidase with singly trifluoroacetylated or trifluoromethylphenylcarbamylated cytochrome c derivatives were studied to determine the role of individual lysines in the reaction. The reaction rate was decreased by modification of the lysines immediately surrounding the heme crevice, the decreases following the order: Lys 13 > Lys 25 Lys 79 ≈ Lys 87 > Lys 8 ≈ Lys 27 ≈ Lys 72. Modification of lysines 22, 55, 88, 99, and 100 had no effect on the reaction rate. These results indicate that the interaction site on cytochrome c for sulfite oxidase is at the heme crevice region, and overlaps considerable with that for cytochrome oxidase. 相似文献
95.
David E. Moody Jacqueline L. James Edward A. Smuckler 《Biochemical and biophysical research communications》1980,97(2):673-679
Treatment of male rats with carbon tetrachloride, bromotrichloromethane, chloroform, 1,2-dibromoethane, 1-bromo-2-chloroethane, and 1,2-dibromo-3-chloropropane results in a decrease in cytochrome P-450 content and alterations in the relative content of fatty acids in hepatic microsomes. A high correlation was found between the loss of cytochrome P-450, the decrease in arachidonic acid (r=0.93), and the increases in linoleic (r=?0.91) and oleic acids (r=?0.89). 相似文献
96.
Summary The effect of aging on the morphology and function of the thyroid gland of the cream hamster was studied by light and electron microscopy coupled with autoradiography or histochemistry.Morphologically, aging induces an accumulation of lysosomal dense bodies and a loss of the phagocytosis of colloid droplets after stimulation with TSH. Iodine uptake and organification occur normally and thyroglobulin synthesis, estimated by autoradiography with 3H-leucine, is not different from that observed in young animals. The basal T4 and T3 plasma levels are lower in the old animals. A low iodine diet administered for several months prevents the age related accumulation of lysosomal dense bodies. Hormone secretion seems to proceed by two different mechanisms; phagocytosis of colloid droplets, the classical mechanism that decreases with age, and an additional mechanism, probably micropinocytosis, that is maintained during the whole lifespan.Presented at the First French Congress of Endocrinology, Montpellier, September 1980Work was performed under contracts n 3.4523.79 and n 3.4512.80 of the Fonds de la Recherche Scientifique Médicale, thanks to a grant of the Ministère Belge de la Politique Scientifique (Action concertée) and with the help of the Fondation Interuniversitaire pour la Recherche du Processus du Vieillissement, Belgium 相似文献
97.
98.
Jacqueline Jollès Jean-Pierre Périn Pierre Jollès 《Molecular and cellular biochemistry》1977,17(1):39-44
Summary The purification of Ostrich (Struthio camelus) egg-white lysozyme is reported. The quantitative amino acid composition, the molecular weight, the N-terminal sequence (34 amino acids) as well as kinetic studies allow to range this enzyme among the goose type lysozymes.106th communication on lysozymes. 相似文献
99.
Mohamed Saïd Hifnawy Jacqueline Vaquette Thierry Sévenet Jean-Louis Pousset André Cavé 《Phytochemistry》1977,16(7):1035-1039
Stems and leaves of Myrtopsis macrocarpa, M. myrtoidea, M. novae-caledoniae and M. sellingii yielded terpenes, sterols, coumarins, alkaloids (furoquinolines and quinolones) and amides. A new quinolone (8-methoxy flindersine) occurs in Myrtopsis macrocarpa, a new amide (N-benzoyltryptamine) in M. myrtoidea, two new coumarins (myrsellin and myrsellinol) and a new dihydrofuroquinoline (myrtopsine) in M. sellingii. Structures of the new compounds are proposed from chemical and spectroscopic evidence. 相似文献
100.
Human β-endorphin administered intracisternally in a dose of 15 μg per rat increased striatal concentrations of the dopamine metabolites, 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) as well as producing catalepsy. These effects were inhibited by naloxone. Pargyline-induced decreases in striatal DOPAC and HVA were greater in endorphin-treated than in saline-treated animals, supporting the concept that β-endorphin increases striatal dopamine turnover. β-endorphin increased the rate of decline in striatal dopamine concentration following synthesis inhibition with α-methyltyrosine, further suggesting that endorphin increases striatal dopamine turnover. β-endorphin and probenecid interacted competitively to decrease the effects of each other to increase striatal HVA. Naloxone prevented the effect of endorphin to decrease the HVA response to probenecid. Thus, probenecid cannot be used to assess the effects of endorphin on striatal dopamine turnover. If β-endorphin acts presynaptically to decrease dopamine release in striatum, the increases in striatal DOPAC and HVA probably represent a compensatory attempt to increase dopamine synthesis. Although turnover of dopamine to its metabolites is increased, dopamine release may be suppressed by β-endorphin. 相似文献