Effects of treadmill running and swimming on plasma and brain vasopressin levels in rats

The influence of treadmill or swimming exercise on resting values of plasma and brain arginine vasopressin (AVP), and plasma sodium, potassium, osmolality and proteins was studied after 5 weeks of training using female Wistar rats. The duration of daily training sessions was progressively increased to reach 6 h/day for swim training (S) and 3 h/day for treadmill running (T). Compared to their untrained controls, treadmill and swim training were respectively associated with: a significant lower body weight; a decreased plasma AVP (36.4% for T and 47.4% for S) and hypothalamic AVP (20% for T and 16% for S); a higher hypophyseal AVP (145% for T and 36.3 for S); a decreased plasma osmolality (6.7% for T and 6.1% for S), sodium (1.2% for both) and potassium (15% for T and 22.4% for S); and no change in protein concentration. For T, rectal temperature increased (38.5 +/- 0.20 to 39.7 +/- 0.5) and for S rectal temperature decreased from 38.6 +/- 0.12 to 37.74 +/- 0.10). The differences observed in AVP contents of the pineal and Harderian glands (enhanced only in the treadmill groups) could be explained by the supposed role of these glands in thermoregulation. Two conclusions could be drawn from this study: there are no parallel changes in the hypothalamo-hypophyseal system (where AVP plays its endocrine role) and the brain (where AVP is a neurotransmitter); plasma changes could be explained by an extracellular fluid expansion with Na and K loss leading to a decrease in AVP secretion.     

Gene-expression profiles predict survival of patients with lung adenocarcinoma

Histopathology is insufficient to predict disease progression and clinical outcome in lung adenocarcinoma. Here we show that gene-expression profiles based on microarray analysis can be used to predict patient survival in early-stage lung adenocarcinomas. Genes most related to survival were identified with univariate Cox analysis. Using either two equivalent but independent training and testing sets, or 'leave-one-out' cross-validation analysis with all tumors, a risk index based on the top 50 genes identified low-risk and high-risk stage I lung adenocarcinomas, which differed significantly with respect to survival. This risk index was then validated using an independent sample of lung adenocarcinomas that predicted high- and low-risk groups. This index included genes not previously associated with survival. The identification of a set of genes that predict survival in early-stage lung adenocarcinoma allows delineation of a high-risk group that may benefit from adjuvant therapy.     

Hyperhydration induced by glycerol ingestion: hormonal and renal responses

The simultaneous time courses of hydromineral hormones (renin-aldosterone system, arginine vasopressin, and atrial natriuretic peptide) and renal responses were examined during and after the completion of hyperhydration induced by glycerol and fluid ingestion. Eight healthy young male Caucasian subjects participated in two separate trials, each including three consecutive phases in a thermoneutral environment. Phases 1 and 3 involved a 90-min period at rest, while phase 2 involved a 120-min period at rest designed to provide either (i) euhydration (control trial) or (ii) hyperhydration induced by ingestion of glycerol (1.1 g/kg body mass) and fluid (21.4 mL/kg body mass). During the 2-h time period of glycerol and fluid ingestion, urine flow, urine osmolality, and plasma levels of hydromineral hormones remained at basal values. In contrast, after hyperhydration completion during phase 3, the diuresis increased markedly together with a dilution of the urine (p < 0.05) while hormonal responses did not change. These results indicate significant differences in renal responses during and after hyperhydration completion and suggest that these changes are independent of fluid-regulating hormonal responses.     

Formation, Metabolism, and Action of Hepoxilin A3in the Rat Pineal Gland

Abstract: The present study was undertaken to investigate the possible formation of hepoxilin A₃ in the rat pineal gland and to study the potential physiological role for this compound in this tissue. Incubation of homogenates of rat pineal glands with arachidonic acid (66 μM) led to the appearance of hepoxilin A₃ (HxA₃) analyzed as its stable trihydroxy derivative, trioxilin A₃ by gas chromatography in both the electron impact and negative ion chemical ionization modes. Endogenous formation of HxA₃ is estimated to be 1.43 ± 0.66 ng//μg of protein. This amount is not modified when the tissue is boiled (2.07 ± 0.66 ng/μg of protein). However, the formation of this compound was stimulated to 21.26 ±5.82 ng/μg of protein when exogenous arachidonic acid was added to the homogenate. Addition of the dual cyclooxygenase/lipoxygenase inhibitor BW 755C (10 /μg) resulted in a partial blockade of hepoxilin formation. Using [1-¹⁴C] H×A₃, we demonstrated that the pineal gland contained hepoxilin epoxide hydrolase, which hydrolyzed HxA₃ into trioxilin A₃. This hydrolysis was inhibited by 1 μmol/L of 3, 3, 3-trichloropropene-1, 2-oxide. In a separate study, HxA₃ in the presence of 3, 3, 3-trichloropropene-1, 2-oxide to block the hydrolysis of HxA₃ decreased the production of cyclic AMP in cultured organ rat pineals after stimulation with 5′-N-ethylcarboxamidoadenosine, an A₁/A₂ adenosine receptor agonist. This effect is stereospecific because the (8S)-enantiomer is more active in decreasing cyclic AMP production (?88.7%) than the (8R)-enantiomer. This is the first demonstration of the presence, metabolism, and action of HxA₃ in the rat pineal gland.     

不同施肥处理对‘赤霞珠’葡萄根际土壤养分和真菌群落的影响

【背景】宁夏贺兰山东麓葡萄产区忽视有机肥的施用,果树枝条焚烧污染环境,造成土壤养分缺失,土壤质量下降。【目的】为解决长期施用化肥对土壤造成的一系列问题,通过大田试验研究施肥及喷施不同浓度菌剂对土壤理化性质、真菌群落组成及多样性的影响,为酿酒葡萄可持续健康发展提供科学依据。【方法】以‘赤霞珠’葡萄根际土壤为试验对象,采用Illumina MiSeq高通量测序技术,测定并分析根际土壤理化性质、真菌群落组成和多样性在7个处理[常规施肥(CK)、蚯蚓粪+腐熟枝条+100倍菌剂(T1)、蚯蚓粪+腐熟枝条+200倍菌剂(T2)、蚯蚓粪+腐熟枝条+300倍菌剂(T3)、蚯蚓粪+未腐熟枝条+100倍菌剂(A1)、蚯蚓粪+未腐熟枝条+200倍菌剂(A2)和蚯蚓粪+未腐熟枝条+300倍菌剂(A3)]的变化。【结果】相较于CK,葡萄根际土壤理化性质差异明显,施肥处理增加了土壤有机质含量,土壤pH含量无明显变化,改良了土壤结构,活化了土壤有效养分。相较于CK,各处理真菌分类操作单元(operational taxonomic unit, OTU)数均降低,A2处理根际土壤丰富度及多样性均显著增加。真菌群落组成...     

Ecdysteroid and juvenile hormone changes in Bombyx mori eggs, related to the initiation of diapause

We describe a method for the routine determination of changes in juvenile hormone levels in insect eggs. The hormones are first converted into their diol derivatives, then they are purified from other lipids and separated by high-performance liquid chromatography (HPLC). The radioimmunoassay of the fractions was then determined. The method permits the simultaneous assay of ecdysteroids, and it was used for determining the hormonal changes in Bombyx eggs during the pre-diapause development. Our major finding is that the hormonal content of eggs dramatically increased prior to the initiation of diapause. This hormonal rise included ecdysone, 20-OH-ecdysone and 3 juvenile hormones. The HPLC retention time of the latter corresponded to JH₁ JH₂ and JH₃. Subsequently, the embryos entered diapause and the hormonal content of eggs was reduced to traces of ecdysteroids. These dramatic changes in juvenile hormone levels during early embryogenesis raise a number of issues which are developed in the discussion.     

Microtubules and cyclic amp in human leukocytes: on the order of things

We have shown previously that the β-adrenergic agonist isoproterenol (2μM) and the phosphodiesterase inhibitor isobutylmethylxanthine (1 mM) produce a much greater increase in cyclic AMP in human leukocytes that have been pretreated with colchicine (or with other agents that affect microtubule assembly) than in control leukocytes. The effects of colchicines were both time- and dose-dependant. These and other data suggested that the generation of cyclic AMP is normally restricted by an intact system of cytoplasmic microtubules. If so, then the same time and dose dependencies might apply to other colchicines-induced changes in leukocyte function. We have now assayed the distribution of concanavalin A (Con A)-receptor complexes on the leukocyte membrane, taking into account that leukocytes competent to assemble microtubules show a uniform distribution of surface- bound Con A whereas microtubule-deficient cells accumulate Con A in surface caps. We have found that the effect of colchicine on capping is also both time- and dose dependent, and that the dose-response relationships conform to those required to increase cyclic AMP levels. These findings provide further evidence that both colchicine-induced Con-A capping and colchicine- induced cyclic AMP generation depend upon the relaxation of constraints normally imposed by cytoplasmic microtubules upon the plasma membrane, which limit, respectively, lateral mobility of the lectin-receptor complexes, and expression of hormone-sensitive adenylate cyclase. Moreover, colchicine-induced Con-A cap formation is not affected even by very large changes in leukocyte cyclic AMP levels. Thus, elevated cyclic AMP levels do not appear to promote the dissolution of microtubules; rather, the dissolution of microtubules permits the generation of increased amounts of cyclic AMP.     

The Regional Concentrations of S-Adenosyl-l-Methionine, S-Adenosyl-l-Homocysteine, and Adenosine in Rat Brain

Abstract: The concentrations of S -adenosyl- l -methionine (SAM), S -adenosyl- l -homocysteine (SAH), and adenosine (Ado) were determined in whole brain and rat brain regions by HPLC. The whole brain contains, respectively, 22 nmol, 1 nmol, and 64 nmol of SAM, SAH, and Ado per g of wet tissue. Their distribution indicated that SAM and SAH levels are highest in brainstem, whereas the Ado level is highest in cortex. With aging the SAM concentrations decrease in whole brain, brainstem, and hypothalamus (–25%) and SAH levels increase by 90% in striatum and by 160% in cerebellum, while Ado levels are increased in all regions by 100–180%.