Odor stimuli trigger influx of calcium into olfactory neurons of the channel catfish   总被引：26，自引：0，他引：26  

D Restrepo  T Miyamoto  B P Bryant  J H Teeter 《Science (New York, N.Y.)》1990,249(4973):1166-1168

Olfactory transduction is thought to be mediated by a G protein-coupled increase in intracellular adenosine 3',5'-monophosphate (cAMP) that triggers the opening of cAMP-gated cation channels and results in depolarization of the plasma membrane of olfactory neurons. In olfactory neurons isolated from the channel catfish, Ictalurus punctatus, stimulation with olfactory stimuli (amino acids) elicits an influx of calcium that leads to a rapid increase in intracellular calcium. In addition, in a reconstitution assay a plasma membrane calcium channel has been identified that is gated by inositol-1,4,5-trisphosphate (IP3), which could mediate this calcium influx. Together with previous studies indicating that stimulation with olfactory stimuli leads to stimulation of phosphoinositide turnover in olfactory cilia, these data suggest that an influx of calcium triggered by odor stimulation of phosphoinositide turnover may be an alternate or additional mechanism of olfactory transduction.  相似文献   

Perturbations in Perigee Height of Vanguard I     

Musen P  Bryant R  Bailie A 《Science (New York, N.Y.)》1960,131(3404):935-936

The effect of solar radiation pressure on the perigee height of satellite 1958ss(2) (Vanguard I) has been considered. Previous consideration of the effect of the third hairmonic and the lunar and solar gravitational perturbations left an unexplained discrepancy between the observed and calculated values of perigee height. The inclusion of the effect of radiation pressure leads to close agreement between the orbit data and the theoretical results for Vanguard I.  相似文献   

Flow Characteristics of Human Erythrocytes through Polycarbonate Sieves     

Gregersen MI  Bryant CA  Hammerle WE  Usami S  Chien S 《Science (New York, N.Y.)》1967,157(3790):825-827

We used polycarbonate sieves with uniform cylindrical pores (2.4 to 6.8 microns in diameter) to filter suspensions of human erythrocytes (mean major diameter is 7.2 microns) in Eagle-albumin solution. With 6.8-micron sieves the pressure-flow curves are convexed to the pressure-axis at low pressures and become linear with high pressures. With 4.5-micron sieves, however, the pressure-flow relationship is linear throughout the range of study. In both types of sieves, flow rate is reduced progressively with increasing concentration of red blood cells (RBC) over a range of 0.5 to 95 percent. The resistance to flow of RBC suspensions is higher in 4.5-micron than in 6.8-micron pores. With filter pore diameters of 3.0 microns or more, the RBC concentration in the filtrate was 100 percent of that in the solution being filtered, but only 70 percent with 2.4-micron pores. The observed critical pore diameter for 100 percent cell transmission agrees with theoretical calculation based on the assumption that the RBC membrane is deformable but nonextensible. The importance of cell deformation in the passage of RBC's through small pores is shown by the inability of RBC hardened in acetaldehyde to pass pores with 6.8-micron diameter.  相似文献   

Flake tools stratified below paleo-Indian artifacts     

Reagan MJ  Rowlett RM  Garrison EG  Dort W  Bryant VM  Johannsen CJ 《Science (New York, N.Y.)》1978,200(4347):1272-1275

In northwest Missouri, Lithic stage flake tools struck from prepared cores have been excavated underlying a Paleo-Indian fluted point assemblage. These assemblages were in two different loesses of the last glaciation. Thermoluminescent analysis of stone tools dates the Paleo-Indian occupations at 8690 +/- 1000 B.C. and 12,855 +/- 1500 B.C.; the Lithic stage occupations must be older than 13,000 B.C. on the basis of geologic correlation, lithic analysis, and cultural stratigraphy.  相似文献   

Bonding in the Molecular Addition Complexes of the Alkyl Phosphates and Thiophosphates     

Wendlandt WW  Bryant JM 《Science (New York, N.Y.)》1956,123(3208):1121-1122

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Accumulation, distribution, and excretion of mirex-14C in animals exposed for long periods to the insecticide in the diet     

G W Ivie  J R Gibson  H E Bryant  J J Begin  J R Barnett  H W Dorough 《Journal of agricultural and food chemistry》1974,22(4):646-653

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Some effects of stocking rate and group size upon agonistic behaviour in groups of growing pigs     

M J Bryant  R Ewbank 《The British veterinary journal》1972,128(2):64-70

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Oestrous behaviour in a herd of dairy cows.     

R J Esslemont  M J Bryant 《The Veterinary record》1976,99(24):472-475

A group of 60 housed Friesian cows were observed continuously for a period of 25 days, during which time all cows were recorded for incidence of mounting activity and 18 selected cows were recorded for various aspects of maintenance activity. All 60 cows were judged as showing oestrus. Average duration of oestrus (+/-SD) in 33 cows was 14-9 +/- 4-7 hours, and the cows were mounted 56-3 +/- 34-8 times. The greatest mounting activity was associated with the night hours. There was no diurnal pattern of onset of oestrus. The majority of mounting activity (79 per cent) occurred in the cubicle area of the building. Comparison of maintenance activities showed that oestrous cows spent, on average, less time standing in a cubicle (P less than 0-01), lying in a cubicle (P less than 0-001) and more time standing elsewhere (P less than 0-001) than non-oestrous cows. The results are discussed in relation to oestrus detection.  相似文献   

Anthelmintic action—A metabolic approach (a review)     

Carolyn A. Behm  C. Bryant 《Veterinary parasitology》1979,5(1):39-49

The effects of anthelmintic drugs on intermediary metabolism of parasites can be examined using techniques developed for the investigation of metabolic regulation. Most attention has been paid to the pathways of respiratory metabolism in parasites, since maintenance of high energy levels is essential to an organism's survival. Respiratory metabolism is thus a prime target for anthelmintic attack. Parasites differ from their hosts in a number of pathways of respiratory metabolism and they produce incompletely-oxidised organic acids as end products.A variety of anthelmintic drugs have been shown to inhibit some enzymes of these pathways, including phosphoenolpyruvate carboxykinase, malate dehydrogenase, and the fumarate reductase, ‘succinoxidase’ and succinate decarboxylase systems. Energy synthesis in mitochondria from parasites is also inhibited by many anthelmintics: this target is a particularly important one since its properties differ significantly from those of the host. This process requires considerable study and it may not necessarily be valid to equate ‘uncoupling’ in mammalian tissues with that in parasite tissues. Changes in ATP levels affect flux through the respiratory pathways; a complete assessment of effects of anthelminstics on the respiratory pathways of parasites would include measurement of the uptake and utilization of carbon sources (e.g., glucose and glycogen), of metabolic intermediates, including adenine nucleotides, and of excreted end products. Sites of change can then be identified and studied in greater detail.Comparison of the effect of mebendazole in vivo and in vitro on unrelated species, Moniezia expansa and Fasciola hepatica adults, sheds some light on the mechanism of its anthelmintic effects. This drug elicits similar changes in proportions and totals of adenine nucleotides in the two species, but it differs in the rapidly of its effect, its effect on glucose uptake and glycogen depletion, and in changes in respiratory end product. Consequently mebendazole may not act in the same way against these two species. It also affects a number of other systems in other parasites: the suggestion of a single ‘mode of action’ may be inappropriate for this compound.Respiratory metabolism is not the only system affected by anthelmintics: other parasite systems are also attacked, but the final effect of lethal anthelmintic is observed as changes in the respiratory metabolic pathways. Some anthelmintics, for example, levamisole, affect the respiratory pathway directly, but also affect other systems (the nervous system in the case of levamisole) and may be effective in vitro but not in vivo. In these cases it is necessary to distinguish between effects that may be subordinate to a primary effect, and to take host and permeability factors into account.  相似文献   

Microsurgery: a new horizon in veterinary surgery     

E R Owen  K Bryant  P R Hopwood 《Australian veterinary journal》1983,60(4):97-100

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