共查询到20条相似文献,搜索用时 46 毫秒
1.
N. Primor 《Cellular and molecular life sciences : CMLS》1985,41(5):693-695
Summary Pardaxin, an active principle of the repellent secretion of the Red Sea flatfish,Pardachirus marmoratus, elicited severe struggling, mouth paralysis, and transient increase in urea leakage from the gills only when administered to the medium bathing the shark's pharyngeal cavity and gills. An apparatus was constructed which prevents a mixing of the outflow from shark's gills with water bathing its surface skin. It is concluded that in sharks the gills and/or the pharyngeal cavity are the target organ for the repellent action of pardaxin. 相似文献
2.
Summary The repellent responses of worker termites to ants are determined by the exocrine gland secretions of the latter. Specialized termite predators produce non-repellent aliphatic alcohols as the major components of their mandibular glands, whereas unspecialized con-generics usually produce repellent ketones and aldehydes.Acknowledgment. A C.A.S.E. Award (C.L.) from S.R.C. and the Centre for Overseas Pest Research is gratefully acknowledged as are facilities provided by the Ahmadu Bello University, Nigeria at Mokwa. 相似文献
3.
Summary A unicellular exocrine gland possessing an epicuticular ductule occurs in grass shrimp gills. This gland displays ultrastructural changes in relation to the molt cycle. These changes include an increase in the quantity of secretory granules during late premolt, and the development of ciliary axonemes in relation to ductule formation.This investigation was supported in part by grant CR-807417 from the U.S. Environmental Protection Agency. 相似文献
4.
The changes in short-circuit current occurring when one or both solutions bathing the intestine of rat or guinea-pig mounted in flux chambers were recorded. The results with the guinea-pig can be explained in terms of diffusion potentials arising from the ionic replacements, and an electrogenic sodium pump, sensitive to ouabain, in the contraluminal membrane of the cell. In the rat, the situation is more complicated, and the enterocyte probably possesses an electrogenic sodium pump in the brush-border membrane. 相似文献
5.
Summary The changes in short-circuit current occurring when one or both solutions bathing the intestine of rat or guinea-pig mounted in flux chambers were recorded. The results with the guinea-pig can be explained in terms of diffusion potentials arising from the ionic replacements, and an electrogenic sodium pump, sensitive to ouabain, in the contraluminal membrane of the cell. In the rat, the situation is more complicated, and the enterocyte probably possesses an electrogenic sodium pump in the brush-border membrane. 相似文献
6.
Tsitsanou KE Thireou T Drakou CE Koussis K Keramioti MV Leonidas DD Eliopoulos E Iatrou K Zographos SE 《Cellular and molecular life sciences : CMLS》2012,69(2):283-297
Insect odorant binding proteins (OBPs) are the first components of the olfactory system to encounter and bind attractant and
repellent odors emanating from various sources for presentation to olfactory receptors, which trigger relevant signal transduction
cascades culminating in specific physiological and behavioral responses. For disease vectors, particularly hematophagous mosquitoes,
repellents represent important defenses against parasitic diseases because they effect a reduction in the rate of contact
between the vectors and humans. OBPs are targets for structure-based rational approaches for the discovery of new repellent
or other olfaction inhibitory compounds with desirable features. Thus, a study was conducted to characterize the high resolution
crystal structure of an OBP of Anopheles gambiae, the African malaria mosquito vector, in complex with N,N-diethyl-m-toluamide (DEET), one of the most effective repellents that has been in worldwide use for six decades. We found that DEET
binds at the edge of a long hydrophobic tunnel by exploiting numerous non-polar interactions and one hydrogen bond, which
is perceived to be critical for DEET’s recognition. Based on the experimentally determined affinity of AgamOBP1 for DEET (K
d of 31.3 μΜ) and our structural data, we modeled the interactions for this protein with 29 promising leads reported in the
literature to have significant repellent activities, and carried out fluorescence binding studies with four highly ranked
ligands. Our experimental results confirmed the modeling predictions indicating that structure-based modeling could facilitate
the design of novel repellents with enhanced binding affinity and selectivity. 相似文献
7.
Summary Diamide, a thiol-oxidizing agent, blocks cAMP-mediated stimulation of Na and water transport when added to the outer solution bathing frog skin. No inhibition was found with diamide in the inner solution. These effects may be due to a perturbation of the thiol-disulfide status of specific components of the outer membrane of the epithelium.This work was supported by grants No. 3.1300.73 and 3.043-0.76 from the Swiss National Science Foundation. 相似文献
8.
Androgen receptors in the cytosol of normal mucosa and of pharyngo-laryngeal epitheliomas in humans]
S Saez F Sakai 《Comptes rendus des séances de l'Académie des sciences. Série D, Sciences naturelles》1975,280(7):935-938
Specific binding for 5 alpha dihydrotestosterone has been characterized in cytosol fraction from human pharyngeal and laryngeal mucosae. The high binding affinity of the protein receptor (Kd 2 x 10(-10)M) and its low capacity are similar in both sexes, and similar in both normal mucosa and epithelioma. 相似文献
9.
G. Tear 《Cellular and molecular life sciences : CMLS》1999,55(11):1365-1376
A key feature of the central nervous system of most higher organisms is their bilateral symmetry about the midline. The specialised
cells that lie at the midline have an essential role in regulating the axon guidance decisions of both neurons that project
axons across the midline and those that project on one side. The midline cells produce both attractive and repellent short-
and long-range signals to guide axonal growth. The axons themselves express specific receptors that can be dynamically regulated
in response to midline-derived signals. In this way, axons extend toward or away from the midline and those that do cross
change their behaviour to respond to longitudinal signals on the contralateral side. 相似文献
10.
Furosemide added to the Ringer solution bathing the external side of the isolated skin of Leptodactylus ocellatus increased the PD and SCC and inhibited both active chloride influx and passive chloride efflux. The action on chloride permeability is thought to contribute to the diuretic effect of the drug. 相似文献
11.
ATPase activity in mercury intoxicated eels 总被引:2,自引:0,他引:2
J. M. Bouquegneau 《Cellular and molecular life sciences : CMLS》1977,33(7):941-943
Summary Eels intoxicated by lethal doses of HgCl2 accumulate mercury in their gills. Mercury inhibits the ouabainsensitive Na+K+ATPase activity of gills involving the rupture of the fish NaCl balance.The author wishes to express his sincere gratitude to Professor A. Disteche and Professor E. Schoffeniels for discussions during the investigation. This research was carried out in participation in the Belgian National Research and Development Program on the Environment-Water-Sea Project-Office of the Prime Minister-Interministerial Commission for Science Policy and Programmation. 相似文献
12.
Summary Blood chemistry ofHeteropneustes fossilis exposed to sewage, fertilizers and inseticides showed signs of anemia, dehydration and disturbance in the pituitary-interrenal endocrine axis and the excretory function of gills. Hepatic and renal tissue damage was also indicated.Financial grant from U.P. State Counc. Sci. Technol., India, is acknowledged. 相似文献
13.
D Jauch 《Experientia》1979,35(3):371-372
The toxic effects of Fenthion on the gills of Cichlid fishes were investigated. In Herotilapia multispinosa hyperplasia and separation of the respiratory epithelium, lamellar telangiectasis and thrombosis occurred. The lamellar epithelium of surviving fish regenerated in all cases. In Tilapia leucosticta no telangiectasis was found, but all the secondary lamellae were fused due to the severe hyperplasia of the gill epithelium. 相似文献
14.
Summary Peaks of proteolytic activity of pharyngeal juice occur at pH 5.75 and pH 7.5. The proteases responsible for digestion include a tryptic alkaline protease and a thiol-activated acid protease which is probably cathepsin B. Levels of proteolytic activity parallel those of other carnivorous invertebrates which feed on zooplankton.This study was supported by operating grants from the National Research Council of Canada.We are grateful to Betsy Sweeney for her technical assistance. 相似文献
15.
Summary Temperature markedly affected the ouabain-sensitivity of both the Na+–K+-activated ATPase activity and the secretion of fluid by the Malpighian tubules ofLocusta. Varying the K+ concentration in the bathing medium did not affect the ouabain-sensitivity of the fluid secretory process. 相似文献
16.
C Chassard-Bouchaud 《Comptes rendus des séances de l'Académie des sciences. Série D, Sciences naturelles》1980,290(4):347-350
Low temperatures (10 +/- 1 degrees C) induce a rapid entry of cadmium into the body across the gills and gut; higher temperatures (20 +/- 1 degrees C) induce a medium and long term absorption and storage of the metal in the digestive gland and its long term accumulation in the exoskeleton. From a methodical point of view, electron microprobe appears more suitable than secondary ion emission microanalysis for the detection of cadmium. 相似文献
17.
Treatment with the co-transport inhibitor, furosemide decreased36Cl– flux across perfused Malpighian tubules ofLocusta. However, exclusion of36Cl– from the bathing medium had not effect on22Na+ flux whereas substitution of bathing medium Na+ by K+ increased36Cl– flux. Diuretic extract of corpora cardiaca increased22Na+ (by 106%) and36Cl– (by 335%) fluxes differentially. 相似文献
18.
Blood chemistry of Heteropneustes fossilis exposed to sewage, fertilizers and insecticides showed signs of anemia, dehydration and disturbance in the pituitary-interrenal endocrine axis and the excretory function of gills. Hepatic and renal tissue damage was also indicated. 相似文献
19.
D. Jauch 《Cellular and molecular life sciences : CMLS》1979,35(3):371-372
Summary The toxic effects of Fenthion on the gills of Cichlid fishes were investigated. In Herotilapia multispinosa hyperplasia and separation of the respiratory epithelium, lamellar telangiectasis and thrombosis occurred. The lamellar epithelium of surviving fish regenerated in all cases. In Tilapia leucosticta no telangiectasis was found, but all the secondary lamellae were fused due to the severe hyperplasia of the gill epithelium.This work was undertaken with the aid of Prof. Dr. E. Kulzer. 相似文献
20.
Summary The loss of42K from the isolated rat diaphragm into the bathing solution is increased by acetylcholine, (a) 3 to 4 days after birth, (b) 7 to 14 days after sectioning of the phrenic nerve. The42K loss is not altered by acetylcholine in the diaphragm of adult rats and after the denervated diaphragm has become reinnervated. 相似文献