Effects of deprivation and scheduling on water intake in the white rat

Two studies are presented to demonstrate that the consummatory behavior of drinking in the rat is under the control of duration of water deprivation and that intake after deprivation is related to variation in the scheduling of the animals' opportunities for drinking.     

Sleep deprivation in the rat

Sleep deprivation, induced by injections of dextroamphetamine or by forced treadmill activity, resulted in a temporary increase in daily sleep time. However, increasing the period of sleep deprivation above 24 hours to 72 or 120 hours did not result in increased recovery sleep above that present in the 24-hour group.     

Diurnal rhythm in endoplasmic reticulum of rat liver: electron microscopic study

Electron microscopy of rat hepatocytes revealed a diurnal variation in the relative amounts of endoplasmic reticulum structures and regional differences in their distribution within the hepatic lobule. The diurnal changes in smooth and rough endoplasmic reticulum structures were compared with the diurnal changes in the hepatic microsomal enzyme hexobarbital oxidase. In the control group, at the time when enzyme activity was maximum, the amount of smooth endoplasmic reticulum was also maximum and vice versa. When the enzyme rhythm was abolished, as in blinded rats, the diurnal rhythm in the endoplasmic reticulum was also abolished.     

Pituitary serotonin content: effects of melatonin or deprivation of water

Relatively high concentrations of serotonin are found in the three regions of the rat pituitary gland. Administration of melatonin causes a selective increase in the serotonin concentration of the pars intermedia; deprivation of water for 5 days causes a selective decrease in the serotonin concentrations of the neural lobe and pars distalis.     

Self-maintained visual stimulation in monkeys after long-term visual deprivation

Newborn monkeys reared in darkness for 16 months, except for daily 1-hour periods of exposure to unpatterned light, were allowed to press a lever to obtain unpatterned light. The animals showed apparently insatiable responding, at rates that were extremely high as compared with rates for normally reared control animals.     

肾间质纤维化的病理与螺旋CT动态增强扫描对照研究

目的通过不同程度肾间质纤维化(RIF)肾穿刺病理检查(RBP)与螺旋CT薄层动态增强扫描(SCTDCS)对照,探讨RIF病理与螺旋CT诊断指标之间的相关性。方法收集经RBP检查证实的正常及轻中重度RIF患者112例,肾活检病理组织行光镜及免疫组化检查,行肾脏SCTDCS作出影像诊断。结果中、重度RIF组肾皮/髓质厚度比、CT值及肾体积改变与对照组相比,差异均具有统计学意义(P<0.05),与轻度组比较,差异无统计学意义(P>0.05);SCTDCS诊断RIF的敏感性为70.7%,准确性为78.6%,特异性为86.7%。结论SCTDCS通过综合判断肾脏相关指标其诊断RIF的敏感性、特异性、准确性较高,可为临床诊断RIF提供影像学依据。     

SD大鼠肾小管上皮细胞两种原代培养及传代方法的比较

目的：建立较理想的大鼠肾小管上皮细胞原代培养、传代及鉴定方法。方法：采用肾小管节段贴块法及0．2％胰蛋白酶消化20min两种方法进行原代培养,以0．25％胰蛋白酶(A组)、0．125％胰蛋白酶-0．02％EDTA(B组)消化传代,利用免疫细胞化学方法鉴定细胞种类。结果：两种方法均能成功培养肾小管上皮细胞,但前者较好,小管节段贴壁早。B组成功传代(4代)并鉴定为肾小管上皮细胞,A组传代失败。结论：肾小管节段贴块、0．125％胰蛋白酶-0．02％EDTA消化是大鼠肾小管上皮细胞原代培养及传代的有效方法。     

Firing patterns of hypothalamic supraoptic neurons during water deprivation in monkeys

Water deprivation in monkeys caused an acceleration of action potential firing of supraoptic neurons, but not of neurons located 2 to 3 millimeters above the hypothalamic supraoptic nucleus. Whereas in the normally hydrated animal only 12 percent of the neuroendocrine cells discharged periodically, the proportion of these periodic bursters increased markedly with increasing plasma osmolarity. This finding suggests that such periodically firing supraoptic neurons are those engaged in active neurohypophyseal hormone secretion.     

Secretion of activin by interstitial cells in the testis

Activin, a dimer formed by the beta subunits of inhibin, has an effect that is opposite to that of inhibin in a number of biological systems. Which cell types secrete activin in vivo is not known. TM3 cells, a Leydig-derived cell line, contained messenger RNAs that hybridized with human beta A and beta B complementary DNA probes and were similar in size to the porcine messenger RNA for the beta subunits of inhibin. No hybridization to the inhibin alpha subunit was detectable in the TM3 cells. Conditioned medium from TM3 cells and from primary cultures of rat and porcine interstitial cells stimulated the release of follicle-stimulating hormone in a pituitary cell culture assay. It is likely that, in the testis, the Leydig cells secrete activin and the Sertoli cells produce inhibin, or a combination of both.     

Manganese and related elements in the interstitial water of marine sediments

Analyses for manganese, nickel, iron, cobalt, sodium, and lithium in the interstitial water of cores from the southern California borderland and six deep-sea cores in the area of the East Pacific Rise show great variation in concentration of trace elements. Oxidizing near-shore sediments showed a 50-fold enrichment in manganese in contrast to sulfide-rich reducing sediments, which showed no enrichment. Deep-sea sediments were variable in their concentration of the trace metals. All but one core showed a high enrichment in dissolved manganese, with a maximum of 6.6 parts per million. Two cores showed a 100-fold enrichment in nickel and cobalt. The manganese appears to be in solution either as Mn(2+) or as a complex. The results appear to support manganese nodule formation in deep-sea sediments through a diffusion of manganese from depth to the surface.     

Selective loss of hippocampal granule cells in the mature rat brain after adrenalectomy

Adrenalectomy of adult male rats resulted in a nearly complete loss of hippocampal granule cells 3 to 4 months after surgery. Nissl and immunocytochemical staining of hippocampal neurons revealed that the granule cell loss was selective; there was no apparent loss of hippocampal pyramidal cells or of gamma-amino butyric acid (GABA)-, somatostatin-, neuropeptide Y-, calcium binding protein-, or parvalbumin-containing hippocampal interneurons. The hippocampal CA1 pyramidal cells of adrenalectomized animals exhibited normal electrophysiological responses to afferent stimulation, whereas responses evoked in the dentate gyrus were severely attenuated. Corticosterone replacement prevented both the adrenalectomy-induced granule cell loss and the attenuated physiological response. Thus, the adrenal glands play a role in maintaining the structural integrity of the normal adult brain.     

Extracellular acidosis protects Ehrlich ascites tumor cells and rat renal cortex against anoxic injury

The present study indicates that extracellular acidosis protects Ehrlich ascites tumor cells and rat kidney cortex cells against injury from anoxia. Parameters measured included cell potassium, adenosine 5'-triphosphate, and uptake of vital dyes. Cells survived longer at a pH of 5.6 to 6.5 than at a pH of 7.4; pH 7.9 was most detrimental. These findings indicate that production of protons by anoxic cells may be a protective feedback mechanism.     

Sleep: changes in threshold to electroconvulsive shock in rats after deprivation of "paradoxical" phase

Rats were deprived of paradoxical (radid eye movement or REM) sleep for a 6-day period but were allowed substantial non-REM (slow wave) sleep. Thresholds for electroconvulsive shock dropped significantly after deprivation in all these animals, but thresholds in control animals treated in a similar manner, but allowed REM sleep exhibited no change. Deprivation seems to heighten neural excitability.     

Retrograde amnesia: electroconvulsive shock effects after termination of rapid eye movement sleep deprivation

Mice that were deprived of rapid eye movement sleep for 2 days immediately after one-trial training in an inhibitory avoidance task and were given an electroconvulsive shock after deprivation displayed retrograde amnesia on a retention test given 24 hours later. Electroconvulsive shock produced no amnesia in comparable groups of animals that were not deprived of rapid eye movement sleep.     

Transfer of experimental autoimmune renal cortical tubular and interstitial disease in guinea pigs by serum

Guinea pigs injected with rabbit tubular basement membranes and Freund's adjuvant develop progressive renal cortical tubulointerstitial disease and deposit autoantibodies in their cortical tubular basement membranes. The identical, even fatal, disease may be produced in normal guinea pigs by a single intraperitoneal injection of serums obtained from guinea pigs with this tubulointerstitial disease, provided such serums contain sufficient amounts of autoantibodies against tubular basement membranes.     

Brines and interstitial brackish water in drill cores from the deep gulf of Mexico

Marked increases in interstitial salinity occur in two drill holes located in the Gulf of Mexico at a water depth of more than 3500 meters. The increases probably arose through diffusion of salt from buried evaporites. In one hole, however, brackish water was encountered on penetrating the oil-permeated cap rock of a salt dome. The phenomenon is attributed to production of fresh water during oxidation of petroleum hydrocarbons and decomposition of gypsum to form native sulfur.     

虾塘养殖对红树林沉积物和间隙水理化性质的影响

红树林湿地在近海水体营养控制和营养盐循环过程中扮演着重要的角色。沉积物、水体和植被相互作用共同维持其生态功能的运转,了解虾塘养殖对林下沉积物和间隙水养分特征影响对评价红树林生态功能具有重要指导意义。本研究以受虾塘养殖废水排放不同影响程度的红树林（无排放区、直排区、修复区）为研究样地,通过不同生境下沉积物与间隙水养分特征的分析,探讨虾塘养殖对他们的影响。结果如下：1）受虾塘养殖废水排放影响区中（直排区、修复区）红树林下沉积物TN与OM、TP呈正相关关系,虾塘养殖废水直排对林下沉积物具有明显酸化作用;2)NH4+-N是红树林下间隙水可溶性无机氮（DIN）的主要组成形式,无排放区沉积物还原性较强,更利于NH4+-N累积在间隙水中;NO3--N与DIN呈极显著相关,虾塘养殖废水排放增强了NO3--N、NO2--N和DIN的累积效应。研究结果表明沉积物和间隙水的理化性质可作为评价虾塘养殖区边邻红树林生境变化规律的定量指标之一。     

分子荧光法对水中氨氮含量的测定

采用分子荧光法对水中氨氮含量进行了测定,在硼酸缓冲液作用下,邻苯二甲醛(OPA)与氨氮反应,生成具有荧光性的物质,在一定的pH、反应温度和静置时间条件下,以362 nm为激发波长,在425 nm发射波长处测定荧光物质的荧光强度,探究了四硼酸钠、亚硫酸钠和OPA混合溶液配比、反应温度、静置时间对衍生物荧光值的影响。结果表明,在一定浓度范围内,衍生物的量与荧光强度有良好的线性关系,该方法灵敏度高,适用于氨氮浓度较低水样的测定,对于高浓度水样也可进行简单稀释后测定。