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PubMed2005

Initial deficit and recovery of function after MDMA preexposure in rats.

RATIONALE: 3,4-methylenedioxymethamphetamine (MDMA) exposure was reported to result in deficits in serotonergic neurotransmission with concomitant behavioral suppression and tolerance to MDMA. Some data have also suggested that the neurochemical deficits recover over time, raising the question as to whether behavioral suppression would show a similar recovery. OBJECTIVES: The possibility of recovery of behavioral deficits was examined in the present study. Rats were administered an MDMA pretreatment regimen that was shown to produce numerous serotonergic deficits and behavioral suppression 2 weeks thereafter. The full expression of MDMA-produced hyperactivity was dependent upon serotonergic integrity, therefore, the present study aimed to determine whether MDMA pretreated rats were tolerant to MDMA 2 weeks after exposure. Further, because serotonergic deficits have shown recovery over time, similar behavioral tests were conducted at a later time point to determine whether functional recovery was evident. METHODS: MDMA-produced hyperactivity was measured at different withdrawal periods (2 and 12 weeks) to determine initial effects and the possibility of recovery of function. RESULTS: In saline-pretreated control rats, +/-MDMA (0.0-10.0 mg/kg) produced a dose-dependent increase in locomotor activity. Rats that had received prior exposure to MDMA (4 x 10 mg/kg MDMA injections administered at 2 h intervals) demonstrated tolerance when the activity was measured 2 weeks after pretreatment. For these rats, there was a downward shift in the dose-effect curve for MDMA-produced hyperactivity. MDMA-produced hyperactivity in rats that were tested 12 weeks after pretreatment was, however, comparable to controls, suggesting recovery of function. CONCLUSION: These data are consistent with the idea that high dose MDMA exposure produces neuroadaptations that exhibit recovery with extended abstinence from the drug.

Animals↗

PubMed2003

Recovery of the benthic macroinvertebrate community in a small stream after long-term discharges of fly ash.

Recovery of the benthic macroinvertebrate community in a small east Tennessee stream impacted by fly ash discharges from a power plant was investigated over a period of 6.5 years. The rate of recovery was greatest in the first 2 years after an initial 75% reduction in coal use led to a similar reduction in ash discharges and associated contaminants; further recovery followed after all fly ash discharges ceased. Recovery of the stream progressed through two phases. In the first phase, which lasted for approximately the first 2 years, most density and richness metrics increased considerably. In the second phase of recovery, the increases in metric values were followed by declines before fluctuating in and out of the lower reference ranges for the metrics. Detrended correspondence analyses and indicator species analyses showed that changes in species composition and community structure were ongoing throughout the second phase. Thus, the first phase was characterized by species additions, while the second phase involved species replacements and shifts in community dominants. Further recovery of the macroinvertebrate community will probably depend on additional flushing of fly ash deposits from the streambed and flood plain, because their continued presence reduces habitat quality in the stream and serves as a potential source of contaminants. Further recovery also may be limited by the availability of vagile species in nearby watersheds.

Animals↗

PubMed1999

Anthropogenic Degradation of the Southern California Desert Ecosystem and Prospects for Natural Recovery and Restoration.

/ Large areas of the southern California desert ecosystem have been negatively affected by off-highway vehicle use, overgrazing by domestic livestock, agriculture, urbanization, construction of roads and utility corridors, air pollution, military training exercises, and other activities. Secondary contributions to degradation include the proliferation of exotic plant species and a higher frequency of anthropogenic fire. Effects of these impacts include alteration or destruction of macro- and micro-vegetation elements, establishment of annual plant communities dominated by exotic species, destruction of soil stabilizers, soil compaction, and increased erosion. Published estimates of recovery time are based on return to predisturbance levels of biomass, cover, density, community structure, or soil characteristics. Natural recovery rates depend on the nature and severity of the impact but are generally very slow. Recovery to predisturbance plant cover and biomass may take 50-300 years, while complete ecosystem recovery may require over 3000 years. Restorative intervention can be used to enhance the success and rate of recovery, but the costs are high and the probability for long-term success is low to moderate. Given the sensitivity of desert habitats to disturbance and the slow rate of natural recovery, the best management option is to limit the extent and intensity of impacts as much as possible.KEY WORDS: Mojave Desert; Colorado Desert; California; Human impacts; Recovery; Restorationhttp://link.springer-ny.com/link/service/journals/00267/bibs/24n3p309.html

Journal Article↗

PubMed2006

Functional recovery improvement is related to aberrant reinnervation trimming. A comparative study using fresh or predegenerated nerve grafts.

Experimentally predegenerated nerve grafts have been demonstrated to improve recovery. In a 12 month-long study, we compared the degree of recovery of conventional and predegenerated grafts in rat median nerve repair. To induce predegeneration the ulnar donor nerve was crushed and grafting to the median nerve was performed 2 weeks later. The day of recovery and the improvement of finger flexion strength were studied by the grasping test. At 3, 6, 9, and 12 months after surgery retrograde labeling studies and flexor carpi radialis muscle ATPase histochemistry were performed. In the predegenerated grafts, the recovery of finger flexion occurred 19.6+/-1.5 days after surgery and was significantly faster than that in the conventional group. Twelve months after surgery, a similar rate of 85% of grasping strength recovery in relation to the normal control rats was demonstrated for the conventional and predegenerated grafts. After grafting, a larger number of motoneurons, compared to the normal controls, were retrograde labeled in the median nerve. This surplus of retrograde labeled motoneurons in the predominantly sensory branch of the median nerve represented misdirected motor fibers. There was a time-related decrease in the number of labeled motoneurons, which correlated to functional grasping strength recovery. Muscle reinnervation induced a predominance of type I over type II muscle fibers. Forty percent of type I fibers were grouped indicating that collateral sprouting plays a prominent role during muscle reinnervation. Regeneration in predegenerated grafts was faster but the final rate of recovery was similar to conventional grafts.

Animals↗

PubMed1999

The role of the intact hemisphere in recovery of midline muscles after recent monohemispheric stroke.

Transcranial magnetic stimulation (TMS) of the motor cortex was used to study basic mechanisms of motor reorganization after major hemispheric stroke in humans. We sought to clarify the possible role of the intact hemisphere in motor recovery of the lingual muscles, and to evaluate the compensatory use of preexisting uncrossed motor pathways projecting to these midline muscles. TMS and bilateral surface recordings from the lingual muscles were carried out in six selected stroke patients who presented with a unilateral lingual paralysis after a limited monohemispheric ischemia. The first examination was performed during the symptomatic stage (t1) and was repeated after complete recovery of lingual function had been established (t2). The cortical motor output patterns were analyzed and compared with the data from 40 healthy controls. In the controls TMS of either hemisphere invariably produced contralateral and ipsilateral compound muscle action potentials (CMAPs), elicited through crossed and uncrossed central motor pathways, respectively. In most individuals an asymmetric cortical motor output pattern was found, as significantly greater mean CMAPs of shorter onset latencies were recorded from the contralateral lingual muscles than from the ipsitateral responses. In the six patients with a unilateral lingual paralysis a similar pattern was found on initial examination by stimulating the intact hemisphere, whereas TMS of the affected hemisphere failed to elicit any CMAP bilaterally. At t2 all patients had regained normal lingual function. Only one patient showed evidence of a complete recovery of the primarily affected hemisphere, as TMS now elicited normal CMAPs bilaterally. In the remaining five patients the unilateral interruption of the corticonuclear pathways persisted in spite of complete functional recovery. In these subjects the recovery of symmetric lingual movements must be attributed to the intact hemisphere. From this it is concluded that recovery of a unilateral lingual paralysis after restricted monohemispheric lesions is possible without recovery of the cortical motor projections from the affected hemisphere. In these cases the intact hemisphere is responsible for restoration of normal lingual movements, most likely by potentiating the effect of preexisting uncrossed motor pathways.

Aged↗

PubMed2002

Recovery of electromyograph median frequency after lumbar muscle fatigue analysed using an exponential time dependence model.

The recovery of the median frequency of the power spectrum of the electromyogram (EMG) after fatigue has been studied to obtain reference data for healthy subjects (n = 55). In a seated position, the subjects performed a 45 s isometric back muscle contraction at 80% of maximal voluntary contraction, followed by 5 s contractions after 1, 2, 3, and 5 min in the recovery phase. In an additional reliability study (n = 11), this was performed six times. Surface EMG was recorded on four sites, namely, bilaterally from the lumbar muscles at the level of the first (L1) and fifth (L5) vertebrae. By non-linear regression, an exponential time dependence model was used to analyse the recovery of median frequency, giving recovery half-time as a resulting measure. Agreement with exponential time dependence was very good (coefficient of determination r(2) = 0.98) in the analysis of mean data (n = 55), with recovery half-times in the range 32-39 s on the four recording sites. Analysis of individual recordings, for which r(2) values in general were lower, revealed further details. Median values of the half-times in general agreed well with the half-times obtained from the analysis of mean data. Recovery half-time and median frequency slope during contraction were not correlated; this is in agreement with what may be expected from an exponential time dependence. Non-significant negative slopes occurred on apparently randomly selected sites, possibly indicating varying muscle coordination in the seated test method. The reliability of the half-time was not sufficient to allow for follow-up measurements on individuals, due to the fluctuations of the recovery data in recordings from individuals.

Adult↗

PubMed2003

Hemodynamics during active and passive recovery from a single bout of supramaximal exercise.

The aim of this work was to study the differences in cardiovascular response during two modes of recovery [active (AR): pedalling at 40 W; and passive (PR): complete rest seated] from a single bout of supramaximal exercise. Eight male amateur soccer players underwent two supramaximal cycle-ergometer tests, each consisting of pedalling against a resistance equivalent to 150% of the maximum workload achieved in a previous incremental test, followed by randomly assigned AR or PR. Cardiodynamic variables were obtained using an impedance cardiograph. Subjects were also connected to a sphygmomanometer, for systolic and diastolic blood pressure, and to a metabolimeter for oxygen uptake (VO(2)) assessments. We measured: heart rate (HR), stroke volume (SV), cardiac output (CO), the inverse of myocardial contractility calculated as pre-ejection period/left ventricular ejection time ratio (PEP/LVET), mean blood pressure (MBP), thoracic electrical impedance ( Z(0)) as an index of central blood volume, and arterio-venous oxygen difference (A-V O(2) Diff.). PR caused a lower CO compared to AR [mean (SE): 7 (0.7) vs. 10.4 (0.6) l.min(-1 )at the 5th min of recovery] due to lower HR [106.2 (3.6) vs. 121.8 (4.5) bpm at the 5th min of recovery], SV [67.1 (5) vs. 86.1 (4.8) ml at the 5th min of recovery], and PEP/VET values [0.44 (0.007) vs. 0.39 (0.015) at the 5th min of recovery]. No differences were found in MBP and Z(0) between PR and AR [95.1 (1.9) vs. 92.3 (2.7) mmHg and 26.2 (1.1) vs. 26.6 (1) Omega respectively at the 5th min of recovery], while A-V O(2) Diff. values were higher during AR than during PR [108.8 (4.3) vs. 75.2 (5.4) ml.l(-1) at the 5th min of recovery]. Thus, although after a single bout of supramaximal exercise SV and CO are lower during PR than during AR, these differences are not due to an impairment of cardiovascular function, but are fully explained by the lesser muscular engagement that leads to a reduction in stimuli deriving from mechanoreceptors and central commands, thus causing a faster return of myocardial contractility and HR to resting values.

Adult↗

PubMedDate not supplied

Serum hormone and myocellular protein recovery after intermittent runs at the velocity associated with VO(2max).

The responses of serum myocellular proteins and hormones to exercise were studied in ten well-trained middle-distance runners [maximal oxygen consumption (VO(2max)) = 69.4 (5.1) ml x kg(-1) x min(-1)] during 3 recovery days and compared to various measures of physical performance. The purpose was to establish the duration of recovery from typical intermittent middle-distance running exercises. The subjects performed, in random, order two 28-min treadmill running exercises at a velocity associated with VO(2max): 14 bouts of 60-s runs with 60 s of rest between each run (IR(60)) and 7 bouts of 120-s runs with 120 s of rest between each run (IR(120)). Before the exercises (pre- exercise), 2 h after, and 1, 2 and 3 days after the exercises, the same series of measurements were performed, including those for serum levels of the myocellular proteins creatine kinase, myoglobin and carbonic anhydrase III (S-CK, S-Mb and S-CA III, respectively), serum hormones testosterone, Luteinizing hormone, follicle-stimulating hormone and cortisol (S-testosterone, S-LH, S-FSH and S-cortisol, respectively) and various performance parameters: maximal vertical jump height (CMJ) and stride length, heart rate and ratings of perceived exertion during an 8-min run at 15 km x h(-1) (SL(15 km x h(-1)), HR(15 km x h(-1)) and RPE(15 km x h(-1)), respectively). Two hours after the end of both exercise bouts the concentration of each measured serum protein had increased significantly (P < 0.001) compared to the pre-exercise level, but there were no changes in SL(15 km x h(-1)) or CMJ. During the recovery days only S-CK was significantly raised (P < 0.01), concomitant with a decrease in CMJ (P < 0.01) and an increase in RPE(15 km x h(-1)) (P < 0.01). Hormone levels remained unchanged compared to the pre-exercise levels during the recovery days and there were no significant differences between the two exercise bouts in any of the observed post-exercise day-to-day responses. With the exception of S-CK, after IR(120) the post-exercise responses returned to their pre-exercise levels within the 3 days of recovery. The present findings suggest that a single 28-min intermittent middle-distance running exercise does not induce changes in serum hormones of well-trained runners during recovery over 3 days, while changes in S-CK, CMJ and RPE(15 km x h(-1)) indicate that 2-3 days of light training may be needed before the recovery at muscle level is complete.

Adult↗

PubMed2004

Social support and recovery in people with serious mental illnesses.

This study examines the relationship between objective and subjective measures of social support with recovery from serious mental illness; recovery has been described as both an outcome state and an ongoing process. One hundred and seventy six people with serious mental illness completed the Recovery Assessment Scale, a process measure of recovery that assessed, among other factors, personal confidence, goal orientation, and non-domination by symptoms. They also were administered the Brief Psychiatric Rating Scale, a semi-structured interview that assesses psychiatric symptom and represents recovery as an outcome. Finally, research participants completed the Social Network Scale, which assessed size of the overall network plus such important subnetworks as family, friends, and health professionals. The SNS also provided measures of the perceived satisfaction with, mutuality in, and obligation towards individuals in their support network. Results showed people with larger overall network size and more network satisfaction were likely to report higher factors on the Recovery Assessment Scale. For the most part, network size and satisfaction was not significantly associated with psychiatric symptoms. Implications of these findings for better understanding the association between social support and recovery are discussed.

Adult↗

PubMed2005

Transforming systems of care: the American Association of Community Psychiatrists Guidelines for Recovery Oriented Services.

Thinking about recovery has grown significantly over the last 70 years, and particularly in the past fifteen. Promotion of recovery has recently been recognized as an organizing principle for the transformation of behavioral health services. Recovery is a personal process of growth and change which typically embraces hope, autonomy and affiliation as elements of establishing satisfying and productive lives in spite of disabling conditions or experiences. Recovery oriented services replace paternalistic, illness oriented perspectives with collaborative, autonomy enhancing approaches and represent a major cultural shift in service delivery. Recovery oriented services replace the myth of chronicity and dependence with a message of individualism, empowerment and choice in the context of collaborative relationships with service providers. The American Association of Community Psychiatrists has developed Guidelines for Recovery Oriented Services to facilitate the transformation of services to this new paradigm. The guidelines are divided into three domains: administration, treatment, and supports, each consisting of several elements for which recovery enhancing characteristics are defined. Several example indicators are also provided for each element. This paper presents these guidelines and discusses their application.

Behavioral Medicine↗

PubMed2003

Recoveries of rat lymph FA after administration of specific structured 13C-TAG.

The potential of the specific structured TAG MLM [where M = caprylic acid (8:0) and L = linoleic acid (18:2n-6)] is the simultaneous delivery of energy and EFA. Compared with long-chain TAG (LLL), they may be more rapidly hydrolyzed and absorbed. This study examined the lymphatic recoveries of intragastrically administered L*L*L*, M*M*M*, ML*M, and ML*L* (where * = 13C-labeled FA) in rats. Lymph lipids were separated into lipid classes and analyzed by GC combustion isotope ratio MS. The recoveries of lymph TAG 18:2n-6 8 h after administration of L*L*L*, ML*M, and ML*L* were 38.6, 48.4, and 49.1%, respectively, whereas after 24 h the recoveries were approximately 50% in all experimental groups. The exogenous contribution to lymph TAG 18:2n-6 was approximately 80 and 60% at maximum absorption of the specific structured TAG and L*L*L*, respectively, 3-6 h after administration. The tendency toward more rapid recovery of exogenous long-chain FA following administration of specific structured TAG compared with long-chain TAG was probably due to fast hydrolysis. The lymphatic recovery of 8:0 was 2.2% 24 h after administration of M*M*M*. This minor lymphatic recovery of exogenous 8:0 was probably due to low stimulation of chylomicron formation. These results demonstrate tendencies toward faster lymphatic recovery of long-chain FA after administration of specific structured TAG compared with long-chain TAG.

Animals↗

PubMed1986

The significance of underlying coronary stenosis for recovery of myocardial function after transient ischemia in the dog.

The rate of recovery of myocardial function after transient coronary occlusion (CO) has been considered to depend on the duration and frequency of CO. However, underlying coronary stenosis has not been previously demonstrated to be a determinant of the rate of myocardial functional recovery. Thus, 12 open-chest dogs were studied to examine the influence of critical coronary stenosis (CCS) on functional recovery after transient CO. Regional functional recovery following 2-minute CO was examined under two different conditions in eight dogs: patent coronary artery stenosis and fixed CSS that exhausted coronary reserve but did not cause a deficit in resting coronary flow or regional function. Following reperfusion with the coronary artery patent, regional function in the ischemic zone was fully recovered (100 +/- 18.0% of pre-CO value) at 30 seconds and was significantly increased (postischemic hypercontraction) compared to pre-CO value at 1 and at 2 minutes after reperfusion. Following CO and reperfusion in the setting of CCS, regional functional recovery was delayed and regional function remained depressed until 2 minutes after reperfusion. No cumulative effect on functional recovery following repeated 2-minute CO was demonstrated in a control group of four dogs. We conclude that coronary artery patency is a determinant of the rate of myocardial function recovery after a transient ischemic episode, and postischemic hypercontractility was suppressed by the underlying CCS.

Animals↗

PubMed1991

Functional recovery of hibernating myocardium after coronary bypass surgery: does it coincide with improvement in perfusion?

To determine the relationship between functional recovery and improvement in perfusion after coronary artery bypass graft surgery (CABG), 49 patients were studied. Radionuclide angiography was performed before, 1 month after, and 6 to 12 months after CABG to evaluate regional wall motion. Exercise thallium-201 myocardial perfusion imaging was done before and 1 month after CABG to assess regional perfusion. Preoperative asynergy was observed in 108 segments, and 74 of them showed an improvement in wall motion 1 month after CABG (segment A). Sixty-six of these segments (89%) were associated with an improvement in perfusion. Eight segments that had not improved 1 month after CABG demonstrated a delayed recovery of wall motion 6 to 12 months after CABG (segment B). However, seven of eight segments (88%) already showed an improvement in perfusion 1 month after CABG. A total of 82 segments exhibited functional recovery after CABG and were considered hibernating segments. In the preoperative study segment B more frequently had areas of akinesis or dyskinesis than segment A (75% vs 34%, p less than 0.05). The mean percent thallium-201 uptake in segment B was lower than that in segment A (74% +/- 9% vs 83% +/- 8%, p less than 0.05). Functional recovery of hibernating myocardium usually coincided with an improvement in perfusion. However, delayed functional recovery after reperfusion was observed in some instances. Severe asynergy and severe thallium-201 defects were more frequently observed in these segments with delayed recovery. Hibernating myocardium might remain stunned during those recovery periods.

Coronary Artery Bypass↗

PubMed1986

Recovery of isolated rat atrial function related to ATP under different anoxic conditions.

Spontaneously beating isolated rat atria were subjected to 1 h of anoxia at 37 degrees C in various cardioplegic solutions. Contraction continued for different times upon initiation of anoxia, depending on the nature of the cardioplegic solution. Two hundred micromolar P1,P5-di(adenosine-5')pentaphosphate (Ap5A) stopped atrial function in less than 30 s of anoxia in contrast to 50 s in the case of Hearse's cardioplegic solution (16 mM MgCl2, 16 mM KCl, 1 mM Procaine), and 20 min in the case of controls. The stopping time was also prolonged from 30 to approximately 50-55 seconds if a lower concentration of Ap5A (100 microM) was used. Function, adenine nucleotides (AN), and phosphocreatine (PCr) were then measured 20 min after reoxygenation. The recovery of both function and AN was most rapid and complete with 200 microM Ap5A (97% recovery in ATP and 100% in function) and least complete in control (50% recovery in ATP and 78% in function). A positive correlation between recovery of ATP, or total adenine nucleotides, and recovery of function was observed in all cases. The higher the level of ATP remaining at the end of 1 h of anoxia and the more recovered after 20 min of reoxygenation, the more complete the recovery of function. The PCr returned to normal or even higher than normal values in all cases, even though function returned only in proportion to ATP. Since PCr is mitochondrial in origin, it appears that loss of a portion of the AN localized at the energy-utilizing sites occurred before serious mitochondrial damage and was responsible for the incomplete postanoxic functional recovery.

Adenine Nucleotides↗

PubMed1989

Serum thyroxine change and clinical recovery in psychiatric inpatients.

Serum free thyroxine (FT4), total thyroxine (TT4), and Brief Psychiatric Rating Scale (BPRS) measurements were obtained following hospital admission and at 2-week intervals during hospitalization in 80 male psychiatric inpatients with a variety of major psychotic and affective disorders. A strong correlation between the range values for BPRS sum and for FT4 (p less than 0.005) and TT4 (p less than 0.001) levels indicated that change in overall symptom severity was linked to change in thyroxine levels during clinical recovery. We found the relationship not to be a simple one, but to require definition of criteria for three patient subgroups for each hormone, taking into account the initial absolute thyroxine level, as well as the direction and magnitude of hormonal change during recovery. The hormonally defined "good recovery" subgroup included patients with high initial thyroxine levels that then fell substantially, patients with low initial thyroxine levels that then rose substantially, and patients with initial thyroxine levels in the middle range that subsequently changed substantially. The hormonally defined "poor recovery" subgroup included those patients not meeting these criteria. The degree of clinical improvement in the hormonally defined good recovery group was significantly greater by almost twofold than the poor recovery group both for FT4 (p less than 0.04) and TT4 (p less than 0.02). These findings suggest that a "normalizing" principle underlies the relationship between clinical recovery and thyroxine levels and that both FT4 and TT4 levels within the normal range appear to have clinical significance in either reflecting or contributing to the course of a variety of psychiatric disorders and possibly having a role in pathogenesis.

Adolescent↗

PubMed1977

Locomotor recovery after unilateral hindlimb deafferentation in cats.

After hindlimb deafferentation, recovery of locomotor patterns may be distinguished from recovery of accurate movements. Cats were timed while crossing wide runways requiring that locomotion be present, and narrow runways which require that it also be accurate. Locomotion recovers soon after deafferentation and becomes almost normal in speed, although accuracy is still absent. This accuracy returns 10 days postoperatively. Ventral root afferents with cell bodies in dorsal root ganglia are unnecessary for recovery. Postural reflexes (and other non-topographic feedback) are used as cues for limb guidance after removal of that limb's topographic feedback. Anatomical experiments show that a thoracic root sprouts during the recovery period. This sprouting may increase the potency of postural reflexes. Although lower thoracic roots contribute to recovery, they are not essential. Ipsilateral descending system are essential, and represent the final common path for all recovery after deaffernting a hindlimb. Contralateral descending and afferent systems alone cannot mediate overground locomotion. Thus there is a difference between the systems which mediate overground locomotion and those used by animals in treadmill locomotion or with L-DOPA or clonidine or brain stem stimulation. The proposed mechanism underlying recovery of accurate locomotion is behavioral substitution which may be faciliated by collateral sprouting of relevant systems.

Animals↗

PubMed1987

Effects of hypoxia and recovery on brain eicosanoids and carbohydrate metabolites in rat brain cortex.

The effects of hypoxia (respiration of 5% O2 for 30 min) and recovery (respiration of air up to 30 min) on brain levels of carbohydrate metabolites, of free arachidonate (FAA) and of several eicosanoids (E) were studied in the rat. Animals were sacrificed before or after 30 min of hypoxia, and during recovery, by microwave radiation (MW). At the end of the hypoxic period, arterial pO2 was reduced to 28 mm Hg and glycemia was elevated. Brain lactate and glucose levels were also elevated, whereas glycogen was unchanged. Levels of free FAA and of E were practically unchanged. During recovery, arterial pO2 values were raised above prehypoxic levels at 5 min and returned to normal within 30 min. The elevated serum glucose declined at 5 min and values returned to normal at 30. Brain glucose was still elevated at 5 min and returned to normal, together with lactate, at 30 min. Brain FAA did not change during recovery, but levels of prostaglandin F2 alpha (PGF2 alpha), prostaglandin E2 (PGF2) and thromboxane B2 (TxB2) were raised, at 5 min, and those of 6-keto-PGF1 alpha were reduced with respect to pre-hypoxia. At the end of recovery, all E were lower than during hypoxia. The results indicate that changes of brain E occur only during recovery from hypoxia. At 5 min of recovery, at high arterial pO2 values, concentrations of all E were elevated, with the exception of 6-keto-PGF1 alpha which was reduced. At 30 min a marked reduction of E levels was observed, possibly resulting from increased clearance following elevation of cerebral blood flow.

Animals↗

PubMed1987

Recovery from calcium-induced damage in a neuroblastoma cell line.

Calcium may act as a second messenger in normal cellular signal transduction systems. However, an excessive influx of calcium into the cytoplasm is well known to be a final common pathway causing cell death under various pathological conditions. The purpose of this study was to investigate the effect of a transient treatment with the calcium ionophore A23187 on the recovery process of cell viability, energy metabolism, amino acid incorporation and calcium uptake in a neuroblastoma cell line. When neuroblastoma cells were treated with 20 microM of the calcium ionophore A23187 in combination with extracellular calcium, rapid energy failure and marked inhibition of amino acid incorporation by the cells occurred together with a massive influx of calcium, and finally resulted in cell death. Recovery from this calcium-induced damage with regards to energy metabolism and prognosis of cell viability was better after a 10-min treatment than after a 30-min treatment with A23187. After a 10-min treatment, the viability was higher in calcium-free medium than in calcium-containing medium in contrast with the cases after treatment for 30 min. The above difference in viability after treatment for 10 min had a very significant correlation with the degree of exclusion of excessive calcium and the recovery of CTP, indicating that the recovery of CTP and the rate of calcium exclusion may be final markers of the recovery of cells from calcium-induced damage rather than the recovery of ATP or amino acid incorporation. Amino acid incorporation was restricted to a level lower than that of the control long after the recovery of GTP and the GTP/GDP ratio.(ABSTRACT TRUNCATED AT 250 WORDS)

Calcimycin↗