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Support for a physiological role of endogenous catecholamines in the stimulation of bovine luteal progesterone production 总被引:2,自引:0,他引:2
To determine if catecholamines were present in bovine luteal tissue, corpora lutea (CL) were obtained during the mid-luteal phase (Days 10-12) and the concentration of dopamine (DA) and norepinephrine (NE) was determined by high-performance liquid chromatography. Both DA and NE were detected in luteal tissue at mean concentrations of 41.9 +/- 5.73 and 10.2 +/- 2.51 ng/g for DA and NE, respectively. These concentrations represented a luteal content of 306.6 +/- 66.88 ng/CL for DA and 70.5 +/- 16.88 ng/CL for NE. In vitro, DA at concentrations of 1.0 mM to 0.01 mM stimulated the production of progesterone (P4, p less than 0.05). The response to DA was inhibited by propranolol (a beta-adrenergic receptor antagonist, p less than 0.05) but not by phentolamine, phenoxybenzamine (alpha-adrenergic receptor antagonists), or haloperidol (a DA receptor antagonist, p greater than 0.05). Neither L-tyrosine nor L-dopa altered P4 production (p greater than 0.05). Inhibition of DA beta-hydroxylase, the enzyme that catalyzes the conversion of DA to NE by FLA-63 blocked the DA-induced increases in luteal P4 production (p less than 0.05). These results demonstrate the existence of DA and NE in bovine luteal tissue and indicate that exogenous DA can be converted to NE in luteal tissue. The results support a physiological role for catecholamines in the stimulation of bovine luteal function. 相似文献
4.
We surveyed primary care physicians in Canada to determine their current practices regarding the detection and treatment of hyperlipidemia in asymptomatic adults 20 years of age or more and to determine the role of selected patient characteristics (age, sex and the presence of coronary heart disease [CHD] risk factors) in their management decisions. The self-administered questionnaire was completed by 428 of 804 family physicians and general practitioners. The proportion of physicians who reported having tested at least 50% of their adult patients varied from 29% to 85% and was related to the number of CHD risk factors present and the patient''s age. The proportion of respondents who reported starting dietary or drug therapy among patients with a cholesterol level of 6.2 mmol/L or less increased as the number of CHD risk factors increased and was not related to patient age or sex. According to the factors examined our results suggest that primary care physicians in Canada select patients for screening and treatment mainly on the basis of CHD risk factors present and that their approach is more conservative than that recommended by the Canadian and US consensus conferences. 相似文献
5.
We have isolated the delta-globin gene of the New-World spider monkey,
Ateles geoffroyi, and compared its nucleotide sequence with those of other
primate delta- and beta-globin genes. Among primate delta-globin genes, the
rate of nonsynonymous substitutions is much less than the rate of
synonymous substitutions. This suggests that primate delta- globin genes
may remain under evolutionary conservation, perhaps because hemoglobin A2
has an as yet unknown physiological importance.
相似文献
6.
Biochemical pathways in prokaryotes can be traced backward through evolutionary time 总被引:10,自引:0,他引:10
For the first time, a credible prokaryotic phylogenetic tree is being
assembled by Woese and others using quantitative sequence analysis of
oligonucleotides in the highly conservative rRNA. This provides an
evolutionary scale against which the evolutionary steps that led to the
arrangement and regulation of contemporary biochemical pathways can be
measured. This paper presents an emerging evolutionary picture of aromatic
amino acid biosynthesis within a large superfamily assemblage of
prokaryotes that is sufficiently developed to illustrate a new perspective
that will be applicable to many other biochemical pathways.
相似文献
7.
Three new alloantigenic specificities of human major histocompatibility complex class 11 molecules have been defined by testing the reactivity of alloantisera at the molecular level. Two of these specificities identify different DR4 haplotypes. The Fe75 specificity is associated with the DR4/DW10 haplotype and the CBC/MRG6 specificity with the DR4/DKT2 haplotype. Both are supertypic specificities and are associated with other DR specificities as well. Both specificities are carried by class 11 molecules belonging to the first DR subset. Together with previously described determinants, these specificities contribute to serological discrimination of the different DR4 haplotypes. 相似文献
8.
STUDIES OF AMINES IN THE STRIATUM IN MONKEYS WITH NIGRAL LESIONS 总被引:2,自引:0,他引:2
M. Goldstein B. Anagnoste A. F. Battista W. S. Owen S. Nakatani 《Journal of neurochemistry》1969,16(4):645-653
The effects of ventromedial tegmental lesions on the biosynthesis and disposition of biogenic amines in the striatum of monkeys were investigated. The concentrations of endogenous dopamine and of the intraventricularly injected [3H]dopamine were distinctly lower in the striatum on the lesion side than on the intact side. The storage of [3H]dopamine in the caudate nucleus was impaired to a much greater extent than the storage of the newly synthesized [3H]norepinephrine. The concentrations of endogenous serotonin and of the intraventricularly injected [14C]serotonin were lower in the striatum on the lesion side than on the intact side. However following MAO inhibition, the concentration of [14C]serotonin did not differ significantly on the two sides of the caudate nucleus. The in vivo biosynthesis of dopamine from tyrosine was significantly reduced in the striatum on the lesion side. Tyrosine hydroxylase and DOPA decarboxylase activities were decreased on the lesion side of the striatum as compared with the intact side. Thus, the ventromedial tegmental lesions affect the storage and the synthesis of dopamine and serotonin in the ipsilateral striatum. 相似文献
9.
In Drosophila pseudoobscura, the amylase (Amy) multigene family is
contained within a series of inversions, or gene arrangements, on the third
chromosome. The Standard (ST), Santa Cruz (SC), and Tree Line (TL)
inversions are central to the phylogeny of arrangements, and have clusters
of other arrangements derived from them. The gene arrangements belonging to
each of these three clusters have a characteristic number of Amy genes,
ranging from three in ST to two in SC to one in TL. This distribution
pattern can reflect a history of either duplications or deletions, although
the data available in the past did not permit a decision between these
alternatives. We provide unambiguous evidence that three Amy genes were
present before the divergence of the ST, SC, and TL arrangements. Thus, the
current status of the Amy multigene family is the result of deletions in
the TL and SC arrangements, which created three new pseudogenes: TL
Amy2-psi, TL Amy3-psi, and SC Amy3- psi. Analysis of pseudogene sequences
revealed that, in the SC and ST arrangements, pseudogene evolution has been
retarded, most likely due to the homogenization effect of gene conversion.
Finally, by determining the original copy number, we have reconstructed the
evolutionary history of the Amy multigene family and linked it with the
evolution of the central gene arrangements.
相似文献
10.
The application of sensory methodology for measuring deodorizing effect of an air conditioner equipped with electric plasma was introduced. Deodorizing effect was measured using chemical and sensory methods at different time (0, 30 and 60 min) and mode (control, blowing and cooling) of an air conditioner. Smoke from a roll of cigarette in a closed room was used as a source of odor and the concentrations of acetic acid and ammonia were measured as odorous chemical components. As one of the sensory methods triangle test was used and as a first step to obtain deodorizing effects by triangle test, the threshold of each panelist was obtained as the log dilution ratio of odor concentration at which the difference from odorless air was detected. The odor concentration at each time and mode was calculated using the threshold of the panel and the deodorizing effect was obtained on the basis of the odor concentration. In addition to a triangle test, scaling methods such as category scaling or magnitude estimation were used to measure deodorizing effect of an air conditioner. Deodorizing effects by scaling methods were calculated based on odor intensity with time at each mode. The regression analysis was done between the efficacy of deodorizing effect by sensory test and those by acetic acid and ammonia, the R2 values of the regression equations for triangle test, category scale, and magnitude estimation were 0.84, 0.72 and 0.69, respectively. Deodorizing effect by triangle test explained the decrease of acetic acid and ammonia better than those by category scaling or magnitude estimation while high cost and time consuming labor involved in triangle tests reduced the merit. The results of this study demonstrated that various sensory methods could be used to measure deodorizing effect of air conditioners and further researches on fast and reliable methods are needed to establish the official procedures. 相似文献