Effect of infusion of hypertonic saline solution of conscious heifers with hypoxemia caused by endotoxin infusion

Thirty male Sprague-Dawley rats were given ciclosporin (Cs) orally, 15 mg/kg daily for 80 days. Fifteen served as positive controls, while the other 15 were given daily colchicine at a dose of 30 microg/kg in addition to Cs. Additional 15 rats were given olive oil only and served as negative controls. The animals were subjected every other week to laboratory assessment of serum creatinine, sodium, potassium, and Cs whole-blood trough levels; also urine samples were examined for creatinine, sodium, potassium, and protein concentrations. At the end point, the animals were sacrificed, and kidney tissue was examined for histopathological changes. Comparing negative control versus Cs-treated and Cs-plus-colchicine-treated rats, there were no significant differences in serum creatinine, creatinine clearance, and serum and urine values of sodium and potassium as well as urinary protein/creatinine ratios. Yet histopathological examination of kidney tissues showed focal tubular atrophy and interstitial fibrosis in inner medulla and inner stripe of the outer medulla in all Cs-treated animals and in only 1 of the colchicine-treated group, but in none of the negative controls. Histological changes in other kidney zones in different animal groups were minor and not different. From this study, we may conclude that colchicine is of protective value against chronic Cs nephrotoxicity in Sprague-Dawley rats.     

Effects of morphine in rats withdrawn from repeated nifedipine administration

The effects of withdrawal from repeated nifedipine treatment on morphine-induced analgesia, hyperthermia and catalepsy as well as on cerebral [3H]nitrendipine binding and on morphine-induced changes in striatal and limbic dopamine and 5-hydroxytryptamine metabolism were studied in rats. Repeated administration of nifedipine (5 mg/kg i.p., twice daily for 14 days) decreased [3H]nitrendipine binding in several brain areas of the rats at 24 h after the last dose but did not change the nociceptive response or rectal temperature of the animals. Further, the antinociceptive potency of acute morphine (2.5 mg/kg s.c.) was significantly reduced in rats withdrawn for 24 h from repeated nifedipine treatment. However, withdrawal from repeated nifedipine treatment failed to affect either the hyperthermia induced by this dose of morphine or the catalepsy and the elevation of dopamine or 5-hydroxytryptamine metabolites induced by 15 mg/kg of morphine. Taken together, these data show that withdrawal from repeated treatment with dihydropyridine calcium channel antagonists selectively reduces the effects of opioids on the nociceptive response.     

Effects of intracerebroventricular infusion of leptin in obese Zucker rats

We have previously reported that the dopaminergic projection from A10 ventral tegmental neurons to the central amygdala is, in part, responsible for the facilitatory effect of angiotensin II (AII) and its 3-7 fragment [AII(3-7)] on the retrieval of information in memory motivated affectively and also on recognition memory. In this study, the influence of both angiotensins, given intracerebroventricularly at the dose of 1 nmol each, in rats lesioned with 6-OHDA to the nucleus accumbens septi (NAS) and to the nucleus septi lateralis (NSL) on recognition memory was evaluated. AII and its 3-7 fragment significantly improved object recognition in sham-operated to NAS and to NSL groups of rats. Bilateral 6-OHDA lesions to NAS totally abolished and to NSL significantly attenuated the facilitatory effect of both angiotensins on object recognition. These results suggest that the dopaminergic projection arriving to the septal structures. NAS and NSL takes part in the facilitatory effect of angiotensins on recognition memory.     

Effects of enteral infusion of hypertonic saline and nutrients on canine jejunal motor patterns

The aim of the study was to clarify the effects of hypertonic solutions on jejunal motility. The study focused on differential effects of hypertonic saline and nutrients. Motility of the canine proximal jejunum was recorded with closely spaced strain-gauge transducers. During fasting, hyperosmotic solutions (up to 1520 mosmol/liter) of saline or nutrients (1 kcal/ml) were infused into the proximal jejunum (0.5-1.5 ml/min) up to 6 hr. The hyperosmotic solutions stimulated jejunal motility. With both increasing osmolarity of saline or increasing energy load of nutrients, jejunal motility linearly declined. The reduction of motility was associated with a change in motor pattern from a propulsive to a more segmenting one. Hypertonic glucose evoked a significantly smaller level of motor activity compared with both saline (at given osmolarities) and an elemental diet (at given energy loads). Motility parameters were not different between glucose and maltose, although osmolarity of maltose was less than half (760 vs 1520 mosmol/liter). In contrast, a mixture of glucose-fructose exerted a smaller inhibition of jejunal motility than glucose. The hypertonic solutions of saline or nutrients were tolerated over 2 hr; with hypertonic saline retrograde power contractions with or without vomiting occurred, whereas with hypertonic nutrients vomiting was preceded by strong inhibition of jejunal motility. Three conclusions can be derived from the present results: (1) The behavior of jejunal motility suggested that the motor activity was the result of both a local stimulation and an inhibitory feedback mechanism. (2) The different degree of inhibition between glucose and saline indicated that the nutrient itself played a major role in the inhibitory feedback regulation, whereas osmolarity was of minor importance. (3) Comparisons between different nutrients suggested a linkage between inhibitory control of motility and the absorptive capacity of the gut for the single nutrient.     

Aversion to a palatable saline solution in rats: Interactions of physiology and experience.

Reports results of 4 experiments with Wistar rats (N = 49). Ss allowed exclusive experience with hypertonic (2%) or isotonic (.9%) saline for 24 hr. displayed a subsequent reversal of the normal spontaneous saline preference when tested in a 2-bottle situation (tap water vs. isotonic saline). Ss trained in this manner were ideally suited to test the hypothesis that saline is a less effective hydrator than is water. It was found that Ss devoid of any confounding preference variables drank much greater quantities of saline when it was offered exclusively than when offered water for a similar period of time. Results suggest that nonpreferers are apparently forced to generate an erroneous 1-bottle saline preference for physiological reasons. (30 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Regulation of intravenously self-administered nicotine in rats.

Ten male Wistar rats had access to 9 doses of nicotine (0.01–0.10 mg/kg iv) during daily 5-hr sessions. Once responding for nicotine stabilized, nicotine infusions were replaced with either cocaine infusions (0.0–2.4 mg/kg) or saline infusions. Saline substitution results indicate that nicotine functioned as a reinforcer. Regulation of nicotine intake was compared with that of cocaine by obtaining the correlation between mean interdose interval and preceding dose size. Results reveal that although this correlation was significant for both nicotine and cocaine self-administration, nicotine self-administration was less precisely regulated than cocaine self-administration. This procedure suggests that there are differences in regulation among self-administered drugs and that it may serve as a useful baseline for studying differences in vulnerability to drug abuse and potential treatment strategies. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Induction of second trimester abortion by infusion of intraamniotic hypertonic and extraamniotic physiological saline solution (author's transl)

In a group of 84 women in the second trimester of pregnancy abortion was induced by intramniotic transabdominal instillation of 20 per cent NaCl. In a second group of 91 women the abortion was induced by means of extraamniotic physiological infusion of saline solution. The only complication observed in the first group was an increasing fever. In the second group there were better results. The fetus abortion was complete and in a shorter time. We assume that the new method is the method of choice because it gives no complications and may be easily performed. It may be used also in cases of missed abortion or intrauterine fetal death.     

Effects of repeated clarithromycin administration on the pharmacokinetic properties of pindolol in rats

The goal of the present work was to determine the effect of clarithromycin (CAM) administration on the pharmacokinetic properties of pindolol in rats. The binding of pindolol to serum components increases proportionally with increasing alpha1-acid glycoprotein (AGP) concentration, indicating that AGP might play a major role in the binding of pindolol. After intravenous administration of pindolol to rats, the CAM-treated group showed a decrease in the volume of distribution, an increase in AUC and no change in the half-life as compared to the control group. Treatment with CAM increased the AGP concentration only. The serum concentration of albumin and creatinine, as well as the metabolic activity of hepatic microsomes towards pindolol, were not altered. Good correlation was observed between the AUC of pindolol in rats and the AGP concentration in serum. Moreover, at 5 min after the administration of an intravenous bolus dose of pindolol to CAM-treated rats, the free concentration of pindolol was lower but the total concentration was higher, compared with the control rats. These results suggested that the influence of CAM on the pharmacokinetic properties of pindolol in CAM-treated rats can be explained by protein binding which, in turn, may be associated with variations in AGP concentration.     

Heparinized saline or normal saline as a flush solution in intermittent intravenous lines in infants and children

Physical exertions are related to sudden cardiac death following acute myocardial infarction (AMI). Abnormalities in the autonomic modulation during exercise were noted in animals with AMI that were susceptible to potentially lethal arrhythmias. This study was done to evaluate the changes in the autonomic activity during exercise and recovery in AMI patients with good exercise capacity, using spectral analysis of R-R intervals of electrocardiogram (ECG). Symptom-limited treadmill exercise test was done on 17 patients of AMI with mild heart failure (in 7-10 days after the attack) and 21 healthy controls. The exercise was divided into 7 stages; rest, early exercise, mid-exercise, peak exercise, early recovery, mid-recovery, and late recovery. Power spectral analysis of R-R intervals of ECG was performed for each stage. Low frequency (0.04-0.15 Hz) and high frequency (0.15-0.40 Hz) powers, and their ratio were obtained. These parameters were observed throughout the stages in both groups. The trend of their changes during exercise and recovery was essentially the same for both groups; high and low frequency powers progressively decreased during exercise and abruptly increased during early recovery, but did not return to the values at those of rest until 9 minutes into the recovery. When the parameters were compared between the groups, there was a significantly greater decrease of high frequency power during the early exercise (p < 0.05), and a higher ratio of low to high frequency power during the early recovery (p < 0.05) in the patients.(ABSTRACT TRUNCATED AT 250 WORDS)     

高浓度盐对氰化物和金属铜的解吸研究

从提金废液中回收氰化物和金属铜一直具有重要的经济价值和环保意义。文中研究了用离子交换法处理含氰废水工艺中的解吸过程，针对试验使用的离子交换树脂寻找了一种简单有效的解吸剂；探索了解吸过程的温度、质量浓度和时间等影响因素，确定了解吸的优化条件。研究表明：高浓度的NaCl溶液能有效地将离子交换树脂上的金属分离解吸下来：该解吸剂尤其适合于高浓度的含铜废液，用20倍床层体积的解吸液对总氰的解吸率达到90％以上，对铜的解吸率达到85％以上，基本不解吸锌；解吸后的溶液可用传统的AVR（酸化、挥发、中和）法或电解．法回收铜和氰。该解吸工艺使解吸过程变得简单、有效，而且解吸剂价格低廉，解吸中无有毒物质产生，同时解决了离子交换树脂再生困难的问题。     

Effects of dietary manipulations and glucose infusion on glucagon response during exercise in rats

OBJECTIVE: To describe our initial experience with a computerized telecommunication system, termed the interactive voice-response system, to record resident performance of laparoscopic surgery. METHODS: After completing a laparoscopic procedure, the surgeon and resident telephone a toll-free number independently and respond to three prerecorded statements using a Likert scale of 1 to 5. The caller then is asked to describe the resident's response to critical incidents or elements of surprise that arose during the surgery. The ratings and verbal comments are compiled, transcribed, and forwarded to the respective resident. The resident (and program director) can hear the verbal comments by entering a four-digit code. RESULTS: Between May 1, 1995, and May 31, 1996, 430 cases were reported by 11 surgeons and 16 residents using the interactive voice-response system. One hundred ninety-five (45%) procedures were entered by both the resident and surgeon. A survey undertaken during the introductory phase of the project revealed that five of the seven residents exposed to the system found that it provided useful feedback and preferred the system to traditional in-service reporting methods. In addition, five residents thought that the system complemented the personal feedback they received in the operating room. CONCLUSION: The system has been accepted by both residents and surgeons and has addressed the important components of resident in-training evaluation, namely, evaluation on a case-by-case basis, timely feedback, and self-assessment of resident performance.     

Morphine reverses the inhibitory effects of repeated saline injections on peritoneal inflammation in mice

AIMS: The lipid composition of platelets and the function of these cells in patients with uremia were studied. METHODS: Fourteen patients and 14 normal volunteers were studied. Platelet lipids including phospholipids and cholesterol, as well as the platelet aggregation response to agonists, were studied. RESULTS: The amount of platelet phospholipids was decreased in patients compared to controls (338.0 +/- 79 vs. 511.6 +/- 125 nmol/10(9) cells; p < 0.001), while the percentage of the five main specimens of these compounds was normal. The content of platelet cholesterol in patients (97.8 +/- 17.0 microg/10(9) cells) was similar to that in controls (91.7 +/- 26.0 microg/10(9) cells). Consequently, the cholesterol:phospholipid ratio in uremic platelets was increased (0.75 +/- 0.1 vs. 0.46 +/- 0.1; p < 0.01). Although this feature is associated with hyperreactive platelets, the aggregation tests were defective for adenosin diphosphate (p < 0.01), arachidonic acid (p < 0.01), epinephrine (p < 0.01) and collagen (p < 0.001). This behavior is probably due to the multifactorial platelet defect described in uremia.     

A delayed suppression of the renin-aldosterone axis following saline infusion in human hypertension

The purpose of this study was to compare the acute suppressibility of the renin-angiotensin-aldosterone (RAA) axis in normotensive (n = 23) and essential hypertensive (n = 62) subjects. Only those hypertensive subjects with normal plasma renin activity (PRA) levels (sodium restricted, upright) were included in the study. Acute suppression of the RAA axis was determined by measuring PRA, plasma angiotensin II (A II), and plasma aldosterone (PA) at frequent intervals during the infusion of isotonic saline (500 ml/hour for 6 hours). Although all parameters fell significantly from control levels by 20-30 minutes in the normotensive subjects, we found that 60% of the hypertensive subjects showed no significant decline in PRA or PA until 120-240 minutes after beginning the infusion. The other hypertensive subjects showed normal RAA suppression. In addition, while there were no significant differences between the three groups in control PRA or PA levels, we found that the PA levels from 30 to 240 minutes during the saline were significantly higher (P less than 0.01) in the hypertensive subjects with delayed suppression. That there were two distinct populations in the hypertensive group was suggested by the bimodality of the frequency response curve, with peaks occurring at 30 and 240 minutes. These studies indicate an abnormality in the acute suppression of the RAA axis in a substantial proportion of subjects with normal renin essential hypertension. Since previous studies in normal subjects have reported that the early phase of response to saline infusion is related to the sodium ion per se and not to intravascular volume expansion, we have come to the conclusion that the present data are consistent with the hypothesis that the delayed suppression hypertensive group has a diminished ability to respond to the sodium ion.     

Olfactory repeated discrimination reversal in rats: Effects of chlordiazepoxide, dizocilpine, and morphine.

Effects of a benzodiazepine (chlordiazepoxide), an N-methyl-D-aspartate receptor antagonist (dizocilpine), and an opiate agonist (morphine) were studied with a procedure designed to assess effects of drugs and other manipulations on nonspatial learning in rats. In each session, rats were exposed to 2 different 2-choice odor-discrimination problems with food reinforcement for correct responses. One problem (performance discrimination) remained the same throughout the study. That is, 1 odor was always correct (S+) and the other was never correct (S-). For the other problem (reversal discrimination), stimuli changed every session. Six different odors were used to program the reversal discrimination; on any given session, S+ was a stimulus that had served as S- the last time it had appeared, S- was a stimulus that had been S+ on its last appearance. Thus, in each session, learning a discrimination reversal could be studied along with the performance of a comparable, but previously learned, discrimination. Chlordiazepoxide interfered with reversal learning at doses that had no effect on the performance discrimination. Morphine and dizocilpine also impaired reversal learning but only at doses that also affected performance of the well-learned performance discrimination. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of neuroleptic and anticonvulsant drugs on repeated acquisition learning in microencephalic and normal rats.

Neuroleptic and anticonvulsant drugs are used to reduce the occurrence of aberrant behaviors, seizures, or both in individuals with mental retardation. However, their use may disrupt the learning of desired skills, and the extent to which anatomical (e.g., microencephaly) or biochemical abnormalities or both in such individuals alter the effects of drugs on learning is not known. In this study, the effects of neuroleptics and anticonvulsants on learning and performance in a repeated acquisition task in methylazoxymethanol-induced microencephalic and saline control rats were assessed. Thioridazine was more potent in microencephalic rats than in control rats in increasing errors and decreasing response rates. Clozapine was equally potent in both microencephalic and control rats in increasing errors and decreasing response rates. The effect of carbamazepine was biphasic in both rat groups: Low doses decreased errors and increased response rates, whereas higher doses did the opposite. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Early isotonic saline resuscitation from uncontrolled hemorrhage in rats

BACKGROUND: Attempts to modify traditional fluid resuscitation have been based on animal models that evaluate several variables including anesthesia. This study presents the effects of early saline resuscitation from severe uncontrolled hemorrhage unanesthetized rats. METHODS: Sixty-three female Sprague-Dawley rats were equally divided into three groups: group A, nonresuscitated; and groups B and C, resuscitated ;with isotonic saline (40 and 80 mL/kg, respectively). Hemodynamics, blood loss, survival time, and mortality were recorded for 360 minutes after the hemorrhage, which was initiated by 75% resection of the tail. RESULTS: In group C, 80 mL/kg of saline significantly lowered mortality (24% vs 76% and 71% for groups A and B, respectively) with concomitant increases in mean survival time (241 +/- 103 min vs 146 +/- 108 and 175 +/- 92 min for groups A and B, respectively). There were no statistically significant differences in blood loss, hematocrit, or hemodynamic parameters among the groups. CONCLUSIONS: Early and adequate isotonic saline resuscitation of unanesthetized rats improved outcome despite continuing hemorrhage. The significantly lower mortality rate and increased survival time were not a result of transiently improved arterial pressure and did not correlate with blood loss. No significant bleeding increases were noted in the resuscitated groups.     

Metabolism of haloperidol to pyridinium species in patients receiving high doses intravenously: is HPTP an intermediate?

The metabolism of haloperidol (HP) to the potentially neurotoxic pyridinium species, HPP+ and RHPP+, has been demonstrated in humans. In vitro studies in microsomes harvested from various animal species indicate that the tetrahydropyridines, HPTP and RHPTP, could be intermediates in this pathway. However, this has not yet been demonstrated in vivo in humans. In this study, plasma and urine collected from eight critically ill patients treated with high doses of intravenous HP were analyzed for HPTP and RHPTP using HPLC with electrochemical detection. However, neither HPTP nor RHPTP were detected despite plasma concentrations of HP and RHP higher than any previously reported. HPP+ and RHPP+ were both present in the urine in high concentrations and accounted for 1.1 +/- 0.5% and 5.3 +/- 3.6%, respectively, of the administered dose of HP. The apparent elimination half-lives of HPP+ and RHPP+ were 67.3 +/- 11.0 hr and 63.3 +/- 11.6 hr, respectively. The absence of HPTP and RHPTP in plasma and urine suggests that in humans these tetrahydropyridines either are insignificant intermediates in the metabolism of HP in vivo or are present only transiently at their site of formation and are not released into the circulation.     

Enzyme induction by repeated adminstration of tetrachlorvinphos in rats

An automated method of sulfate analysis is described, which can detect sulfate concentrations as low as 2.5 mug per ml water. The assay is based on the reaction of sodium rhodizonate and barium forming a colored complex. Sulfate quantitavely interferes with this reaction. The assay is reproducible in the range of 2.5 to 30 mug sulfate per ml water. This method conveniently and accurately measures water soluble sulfate filtered from the air, and is especially useful in assaying samples containing microgram quantities of sulfate from experimental inhalation apparatus.     

Effects of hepatic portal infusion of deionized water on metabolic and hormonal responses to exercise in rats

The present study was conducted to investigate the in vivo effects of an intrahepatic infusion of deionized water during exercise in rats. Adrenodemedullated male Sprague-Dawley rats were continuously infused for 30 min either at rest or during treadmill exercise (26 m/min, 0% grade). Rats were randomly assigned to one of three infusion conditions (52 micro ul/min) with either deionized water (PW) or saline (PS; NaCl; 0.9%) via the hepatic portal vein or deionized water through the jugular vein (JW). The exercise period caused a significant (P < 0.05) decrease in liver glycogen and relative liver water content and peripheral and portal blood glucose and insulin while increasing peripheral and portal glucagon and K+ plasma concentrations. These responses, with the exception of K+, were not influenced by the different types of infusions. The increase in K+ during exercise was significantly (P < 0.05) higher in JW rats than in the PW and PS groups. Both the infusion and exercise protocols did not significantly alter the liver weight-to-body weight ratio, plasma osmolality, free fatty acids, beta-hydroxybutyrate, Na+, Cl-, vasopressin, and catecholamine concentrations. It is concluded that an hepatic portal infusion of deionized water does not specifically alter the metabolic and hormonal responses to exercise in rats.