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61.
62.
Julio Fernández Pardal Enri Borda Martha F. Gimeno Alvaro L. Gimeno 《Life sciences》1981,29(15):1583-1589
The spontaneous 3H-noradrenaline efflux from the isolated epididymal and prostatic portions of the rat vas deferens, was investigated. The spontaneous tritium efflux was higher in the epididymal portion than in the prostatic one from normal animals. Such differences were abolished after castration. On the other hand, acetylsalicylic acid enhanced the total tritium efflux only in the epididymal portion, whereas phentolamine and phenoxybenzamine increased the total tritium efflux from the two portions of the rat vas deferens in both experimental groups. The prostatic portion released a similar amount of 3H normetanephrine than the apididymal end, whereas other metabolic fractions (3,4-dihydroxyphenylglycol; 3,4-dihydroxymandelic acid and O-methylated deaminated metabolites) were smaller in the prostatic portion in comparison with the epididymal portion from control vas deferens. The results presented in the isolated rat vas deferens suggest the existence of a prostaglandin as well as an alpha adrenoceptive modulation of the spontaneous total tritium efflux. 相似文献
63.
D. Christine Sigurdson Martha E. Gaarder Dennis M. Livingston 《Molecular & general genetics : MGG》1981,183(1):59-65
Summary The transmission of the yeast 2 m DNA plasmid has been examined in heterokaryons formed between a haploid donor cell containing the plasmid and a haploid recipient cell lacking the plasmid. Strains lacking the plasmid were mated to donor strains and cytoductants, haploid exconjugants arising from heterokaryons, were selected. The cytoductants bearing the genotype of the recipient cells were then tested for the presence of 2 m DNA. The frequency with which the recipient received plasmid copies varied between 0 and 46%. This frequency depended on the recipient strain but was not highly dependent on whether or not the donor strain carried a kar1 mutation. Exceptional cytoductants, which had acquired a chromosome from the mating partner, were examined and found to have a much greater probability of acquiring plasmid DNA than cytoductants in general. This correlation supports the contention that plasmid copies are associated with the nucleus. In one mating the donor strain contained nearly equal amounts of two physically distinct plasmid types. Of the cytoductants bearing the recipient genotype which had acquired the plasmid during mating, most contained only one of the two plasmid types present in the donor. Analysis of this result using a Poisson distribution indicates that the average number of plasmid copies transmitted between nuclei of a heterokaryon is 0.2. 相似文献
64.
Twenty-two strains of the Center for Disease Control’s IIk-2 group of nonfermentative Gram-negative, weakly pigmented (yellow)
bacteria were examined in respect to phenotypic features, DNA base composition, and both intra-and extra-group DNA-DNA hybridizations.
Eighteen of the 22 strains appeared to be members of one taxon. This taxon is phenotypically not similar to two genera,Acinetobacter andMoraxella, which have similar base compositions. It does, however, have phenotypic features and base composition compatible with those
of the genusFlavobacterium. 相似文献
65.
Thermoregulatory behavior of juvenile cromileptes altivelis (serranidae), a tropical marine fish 总被引:1,自引:0,他引:1
Ten juvenile Cromileptes altivelis were tested individually for 3-day periods in electronic shuttleboxes to measure their thermoregulatory behavior. The fish voluntarily occupied a 21–27°C span, out of a potentially available 0–50°C range. The mean final thermal preferendum was 24.5°C for all individuals. The thermoregulatory performance of this species is similar to that of cool temperate freshwater fishes. 相似文献
66.
67.
Goldfish (Carassius auratus) and bluegill sunfish (Lepomis macrochirus) were placed in aquaria where their locomotor activity was monitored by photocells, and tested at various acclimation temperatures over a range encompassing their final thermal preferenda. Activity was pooled over 24-hour periods to eliminate any circadian rhythm effects. Both species exhibited an activity well of reduced locomotor activity in the region of the final preferendum. Goldfish, tested either singly or in groups of 2–5 individuals, exhibited a social-interaction effect which became more pronounced at higher temperatures. These results are discussed in relation to a thermokinetic interpretation of thermo-regulatory behavior in fishes, and to the correspondence between thermal preferenda and thermal optima. 相似文献
68.
Twenty bluespotted sunfish, Enneacanthus gloriosus, were individually tested for thermoregulatory behavior in an electronic shuttlebox. The first fishes of this genus to be tested for thermoregulatory behavior, these individuals were captured near the northern limit of their zoogeographic range, in northeastern Pennsylvania. The mean final preferendum from pooled data of all 20 fish was 28.5°C; there were no significant differences between day and night. 相似文献
69.
At least four genes regulate the primary immune response to ovalbumin in mice. The ability to be sensitized to transfer delayed type hypersensitivity to ovalbumin is controlled by two genes. One gene,OVA-, is linked to theH-2 complex and maps to the left ofI-E. The linkage of the other gene,OVA-Bg1, has not been determined, but it segregates independently of theLy M locus, of the heavy chain allotype genes and of certain genes controlling coat color. At least two genes regulate the ability to respond with a primary antiovalbumin antibody response. One gene,OVA-, is linked to theH-2 complex and maps to the right ofI-E. Discordance of the minimum dose of antigen needed to elicit delayed type hypersensitivity response and antibody suggests that non-H-2 gene(s) regulating the primary antibody response are different fromOVA-Bg1.Abbreviations used in this paper BSA
bovine serum albumin
- DTH
delayed type hypersensitivity
-
H-2
major histocompatibility complex of mouse
-
Ir
gene — immune response gene
- OVA
ovalbumin
- SRBC
sheep red blood cells 相似文献
70.