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1.
The direct effects of alpha- and beta-adrenergic agents on PRL and beta-endorphin (beta-END) secretion in vitro by porcine pituitary cells have been investigated. Pituitary glands were obtained from mature gilts, which were ovariectomised (OVX) one month before slaughter. Ovariectomised gilts, assigned to four groups, were primed with: (1) vehicle (OVX); (2) and (3) oestradiol benzoate (EB; 2.5 mg/100 kg b.w.) at 30-36 h (OVX+EB I) and 60-66 h (OVX+EB II) before slaughter, respectively; and (4) progesterone (P4; 120 mg/100 kg b.w.) for 5 consecutive days before slaughter (OVX+P4). Isolated anterior pituitary cells were submitted to 3.5 h incubation in the presence of GnRH, alpha- and beta-adrenergic agonists [phenylephrine (PHEN) and isoproterenol (ISOP), respectively], or alpha- and beta-adrenergic blockers [phentolamine (PHENT) and propranolol (PROP), respectively]. The culture media were assayed for PRL (exp. I) and beta-endorphin-like immunoreactivity (beta-END-LI) (experiment II). In experiment I, GnRH did not influence PRL release by pituitary cells in all experimental groups. Some of tested doses of adrenergic agonists, PHEN and ISOP, increased PRL release from pituitary cells of OVX gilts, but not from those of OVX+EB I animals. In the OVX+EB II group, PHEN alone, but ISOP with PROP, potentiated PRL secretion by the cells. In OVX+P4 animals, PHEN alone or in combination with PHENT and also ISOP alone or with PROP enhanced PRL output from the cells. In experiment II, addition of GnRH increased beta-END-LI release from pituitary cells only in the OVX+EB II group. PHEN and PHENT potentiated beta-END-LI secretion by pituitary cells in OVX+EB II and OVX+P4 groups, while ISOP and PROP increased beta-END-LI secretion by the cells of OVX and OVX+EB II animals. In turn, in the OVX+EB I group, effect of PHENT and PROP on PRL secretion by pituitary cells was inhibitory. In conclusion, our results suggest that adrenergic agents can modulate PRL and beta-END secretion by porcine pituitary cells in a manner dependent on the hormonal status of gilts.  相似文献   
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ABSTRACT

The content of macronutrients in potato tubers arouses interest because of their substantial consumption in the world and significant role in elements' budget in human diet. The research objective has been to evaluate the content of macronutrients in tubers of potatoes grown in different systems of crop production in Poland. In 2012–2014, an experiment was conducted to test potato cultivation in three-crop production systems: conventional, integrated and organic. In each of the six-field crop rotation systems, there were five potato cultivars classified into different earliness groups. The following macronutrients in dry mass of potato tubers were determined: N, P, K, Ca, Mg, Na, S and Cl, and the various ratios between them were calculated. The research carried out proved that potatoes production systems affect the chemical composition of tubers, which is additionally modified by whether condition and genetic features of cultivars. Potato tubers from organic farming contained by about 20% less N than tubers from conventional or integrated systems. Potato tubers from organic production system displayed lower content of Ca and Na in comparison with the conventional and integrated systems. The least of P and S were detected in tubers of the potatoes grown conventionally.  相似文献   
3.
Using Tn5 mutagenesis of lysogenic Sinorhizobium meliloti strain L5–30 (L54), three neomycin-resistant transconjugants differing in phage-resistance profiles were isolated. Two of them increased the dry weight of plants and were capable of establishing root nodules, whereas the third one was ineffective. The bacterium-phage interaction did not have observable consequences in the Medicago sativa - S. meliloti symbiosis because it did not affect the number of nodules on M. sativa or plant dry weight.  相似文献   
4.
The influence of manure and composts on the leaching of heavy metals from soil was evaluated in a model lysimeter experiment under controlled conditions. Soil samples were collected from experimental fields, from 0- to 90-cm layers retaining the layout of the soil profile layers, after the second crop rotation cycle with the following plant species: potatoes, spring barley, winter rapeseed, and winter wheat. During the field experiment, 20 t DM/ha of manure, municipal sewage sludge composted with straw (SSCS), composted sewage sludge (SSC), dried granular sewage sludge (DGSS), “Dano” compost made from non-segregated municipal waste (CMMW), and compost made from municipal green waste (CUGW) was applied, i.e., 10 t DM/ha per crop rotation cycle. The concentrations (μg/dm3) of heavy metals in the leachate were as follows: Cd (3.6–11.5)?<?Mn (4.8–15.4)?<?Cu (13.4–35.5)?<?Zn (27.5–48.0)?<?Cr (36.7–96.5)?<?Ni (24.4–165.8)?<?Pb (113.8–187.7). Soil fertilization with organic waste materials did not contaminate the percolating water with manganese or zinc, whereas the concentrations of the other metals increased to the levels characteristic of unsatisfactory water quality and poor water quality classes. The copper and nickel content of percolating water depended on the concentration of those metals introduced into the soil with organic waste materials. The concentrations of Cd in the leachate increased, whereas the concentrations of Cu and Ni decreased with increasing organic C content of organic fertilizers. The widening of the C/N ratio contributed to Mn leaching. The concentrations of Pb, Cr, and Mn in the percolating water were positively correlated with the organic C content of soil.  相似文献   
5.
This work presents the results of a study of changes in the soil mineral components and the related modifications of the chemical composition and surface properties of soils in the desert-steppe zone in the southern part of the Ergeni Upland. Burial mounds dating back to the Bronze epoch have been investigated. According to radiocarbon data, their ages are estimated at 5100 ± 50, 4410 ± 100, 4260 ± 120, 4120 ± 70, and 3960 ± 40 years. The substantial transformation of the clay minerals, the molar chemical coefficients, the magnetic mineralogy, and the surface properties of the soils permits us to assess the rates of the mineralogical transformations caused by the climate change during the time interval of less than <∼100 years. The ratio between the content of the mineral phases in the buried soils of different ages testifies to the primary importance of climatic factor in comparison with the total duration of weathering or the soil existence on the land surface prior to its burial, i.e., the soil age.  相似文献   
6.
The objective of the study was to examine the expression of the genes coding for proopiomelanocortin (POMC), proenkephalin (PENK) and prodynorphin (PDYN) in porcine luteal cells isolated from corpora lutea (CL) collected on days 3-6, 8-10 and 13-16 of the oestrous cycle. Total RNA was purified from non-incubated cells and from cells incubated for 48 h in the absence or presence of luteinising hormone (LH). The semi-quantitative RT-PCR technique, involving coamplification of the target and control cDNA (beta-actin or 18S rRNA), was used to examine gene expression. It was found that the genes coding for opioid precursors are expressed in both non-incubated and incubated porcine luteal cells representing the early, mid- and late luteal phase. In non-incubated cells, only POMC mRNA content changed during CL development, whereas the expression of PENK and PDYN genes remained relatively constant. Additionally, the treatment of cells with LH markedly affected the expression of POMC and PENK, but no influence on PDYN expression was observed. The present study indicates that porcine luteal cells may produce opioid peptides and that gene expression of their precursors (except for PDYN) may be modulated in these cells by LH. Moreover, the present results support the involvement of opioid peptides in local regulation within the CL of the pig.  相似文献   
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In the moderate climate of Poland it is recommended that milk thistle (Silybum marianum L. Gaertn.) be grown on fertile soils. The plant, however, develops a strong root system, so a working hypothesis has developed that cultivation can be extended to light soils with periodic water deficits. The aim of the present research was to determine the effects of sowing milk thistle on light soil at different dates and rates on the achene yield and flavonolignan content. This experiment was carried out during 2004-2006 at the Mochelek Experiment Station of the University of Technology and Life Sciences in Bydgoszcz (53°13′ N; 17°51′ E). The average fruit yields were 1.23 t ha−1; those of silymarin were 26.5 kg ha−1. The moisture and thermal conditions during the research years caused the fruit yields to range from 0.55 to 1.68 t ha−1 and silymarin yields from 13.3 to 35.4 kg ha−1. Delaying sowing from early to mid-April increased the plant density and decreased numbers of inflorescences and fruits per inflorescence; as a result, no effect of sowing date on fruit yield was found. Delaying the sowing date increased silymarin content by about 0.4% and its yield by 5.3 kg ha−1. Increasing the sowing rate from 12 to 24 kg ha−1 resulted in a slight (40 kg ha−1) but significant increase in achene yield; however, it did not affect the silymarin content. The average silymarin content in fruits was 2.18%. The ratio of silydianin to silychristin was 1:2.2, and the ratio of silydianin to the sum of silybinin and isosilybinin was 1:3.3.  相似文献   
10.
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