Renal excretory responses produced by the delta opioid agonist, BW373U86, in conscious rats

This study compared the traditional two-compartment (fat mass or FM; fat free mass or FFM) hydrodensitometric method of body composition measurement, which is based on body density, with three (FM, total body water or TBW, fat free dry mass)- and four (FM, TBW, bone mineral mass or BMM, residual)-compartment models in highly trained men (n = 12), sedentary men (n = 12), highly trained women (n = 12), and sedentary women (n = 12). The means and variances for the relative body fat (%BF) differences between the two- and three-compartment models [2.2 +/- 1.6 (SD) % BF; n = 48] were significantly greater (P 相似文献   

Age and gender differences in cardiac reactivity and subjective emotion responses to emotional autobiographical memories.

This research reports age and gender differences in cardiac reactivity and subjective responses to the induction of autobiographical memories related to anger, fear, sadness, and happiness. Heart rate (HR) and subjective state were assessed at baseline and after the induction of each emotion in 113 individuals (61 men, 52 women; 66% European American, 34% African American) ranging in age from 15 to 88 years (M = 50.0; SD = 20.2). Cardiac reactivity was lower in older individuals; however, for anger and fear, these age effects were significantly more pronounced for the women than the men. There were no gender differences in subjective responses, however, suggesting that the lower cardiac reactivity found among older people is dependent on gender and the specific emotion assessed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Vigilance and cardiovascular reactivity to subsequent stressors in men: A preliminary study.

Understanding moderators of acute responses to stress has implications for a variety of outcomes in health psychology. The present study investigated the role of sustained search for potential threat in acute cardiovascular stress responses. As a means of manipulating vigilance for threat in the laboratory, male participants (N?=?30) were randomly assigned to search, on a computer screen, for statements that were negative, positive, or occurring at known intervals. Relative to participants in the other search conditions, participants in the negative search condition had significantly higher systolic and diastolic blood pressure responses during subsequent stressors. These results encourage a closer look at the effects of vigilance for threat. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Electroencephalographic responses to photic stimulation in habitual smokers and nonsmokers.

Performed 2 studies in which EEGs of 45 habitual cigarette smokers and of 59 nonsmokers were taken before and after they were required to smoke a cigarette. The EEGs were scored for incidence of EEG "driving" responses to photic stimulation, an index that appears to reflect the balance between central adrenergic and cholinergic nervous systems. Findings suggest that smokers tend to have a central autonomic balance less in favor of adrenergic functioning than do nonsmokers. Cigarette smoking may alleviate a possible central adrenergic insufficiency of smokers. These findings suggest a solution to "Nesbitt's paradox," which has reference to the fact that while nicotine is a central adrenergic stimulant, smokers describe the effect of smoking in sedational terms (i.e., as relaxing or calming). (22 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Relationship of racial stressors to blood pressure responses and anger expression in Black college students.

27 Black college students viewed 3 excerpts showing racist situations involving Blacks; anger-provoking, nonracist situations; and neutral situations. After each scene, blood pressure (BP) was taken; a mood checklist, the Framingham Anger Scale (S. Haynes et al; see PA, Vol 68:10702), and the Anger Expression Scale of C. Spielberger et al (1985) were administered. Analyses revealed that BP significantly increased during the presentation of racist stimuli but not of anger-provoking or neutral stimuli. Self-reports of state anger, as measured by the mood checklist, were significant for both the anger-provoking and racist stimuli. BP scores were significantly correlated to the 2 trait anger measures. Exposure to racist stimuli was associated with BP increases among Blacks. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Collective efficacy versus self-efficacy in coping responses to stressors and control: A cross-cultural study.

This study examined how cultural differences and efficacy perceptions influence the role of job control in coping with job demands. Perceiving higher control mitigated the effects of demands on psychological health symptoms and turnover intentions only among American bank tellers reporting high job self-efficacy. Among American tellers reporting low job self-efficacy, perceived control exacerbated the effects of demands. However, in a matched Hong Kong sample, collective efficacy interacted in the same way with control and demands as job self-efficacy had in the American sample. These differences appear to be explained by the individual attributes of idiocentrism and allocentrism that are linked to the societal norms of individualism and collectivism, respectively. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cardiac and behavioral responses to repeated tactile and auditory stimulation by preterm and term neonates.

Auditory stimuli (a buzzer and rattle) and a tactile stimulus (a plastic filament) were repeatedly presented to 18 term and 18 preterm infants. Both groups initially responded to all stimuli with increased limb movements and heart rate acceleration. However, only the term infants responded to stimulus repetition by decreasing both cardiac and behavioral responses. In addition, they differentially responded to the 3 stimuli and showed response recovery in both systems. Since a behavioral response decrement was observed without a cardiac response decrement in the preterm group, a 2nd experiment was conducted. Heart rate change during the sucking activity of Exp II revealed an integration between autonomic and motor responsivity of preterm infants comparable to that of term newborns. The lack of cardiac–behavioral response integration during Exp I is discussed in the context of state differences between preterm and term infants as well as potential immaturity or some insult experienced by the preterm infants. The stimulus discrimination and habituation demands of Exp I may have overtaxed the preterm infants' ability to maintain response integration. (23 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Autonomic reactivity to sensory stimulation in psychopathic, neurotic, and normal juvenile delinquents.

To test the hypothesis that lowered reactivity and/or more rapid adaptation to sensory inputs is a primary characteristic in psychopaths, 19 psychopathic, 21 neurotic, and 26 normal juvenile delinquents were identified by a behavior checklist and were presented with 21 successive tone stimuli while skin conductance and heart rate (HR) were being monitored. Results indicate that psychopaths gave significantly lower GSRs to the initial stimulus and lower, though not significantly lower, HR changes and prestimulus to poststimulus basal skin conductance increases. Skin conductance levels during rest and stimulation periods were not significantly different. It is concluded that the psychopathic autonomic characteristic resides in lower initial reactivity and not in more rapid adaptation, at least in response to a simple auditory stimulus. (18 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cardiorespiratory and renal responses to arterial chemoreceptor stimulation by hypoxia or almitrine in men

1. The cardiorespiratory and renal responses to 3 h of normobaric whole-body hypoxic hypoxia (FiO2 = 0.12) as well as to arterial chemoreceptor stimulation by the oral administration of 100 mg almitrine bismesylate during normoxia were measured in 12 normotensive young men undergoing water diuresis. A third series of responses obtained under comparable conditions in the same subjects served as time controls. 2. No significant changes could be detected over time in the parameters measured in control experiments. The subjects reacted to both whole-body hypoxic hypoxia and to pharmacological chemoreceptor stimulation with significant increases in heart rate, tidal volume, minute ventilation and filtration-fraction. Overall renal vascular resistance rose significantly in hypoxia; increases in renal vascular resistance in almitrine experiments were not significant. 3. Renal fractional lithium excretion decreased significantly in response to whole-body hypoxic hypoxia and increased slightly in response to almitrine. Fractional urine and sodium excretion showed negligible changes. 4. The data indicate that, in humans, both almitrine and whole-body hypoxic hypoxia affect not only alveolar ventilation but also renal haemodynamics. 5. The renal electrolyte excretion pattern suggests that under certain circumstances (e.g. dilated renal vascular bed) acute, but well-tolerated, whole-body hypoxic hypoxia can simultaneously stimulate renal proximal tubular sodium reabsorption and inhibit distal tubular sodium reabsorption. The renal tubular responses also indicate that almitrine may influence renal tubular lithium reabsorption by, thus far, unknown mechanisms.     

Intraoral intake and taste reactivity responses elicited by sucrose and sodium chloride in chronic decerebrate rats.

Oral stimulating effects of sucrose and NaCl were assessed in chronic decerebrate and pair-fed intact control rats by measuring oral motor taste-reactivity responses (TRRs) and intraoral intake (II) volume. TRRs were videotaped during the 1st minute of the intraoral taste infusion. The infusion continued until the taste solution was rejected from the mouth, and the intake volume was computed accordingly. The number of ingestive TRRs and the volume of II consumed by pair-fed control and decerebrate rats increased with increasing sucrose concentration. Sucrose intake increased as concentration increased, then plateaued for both groups. For controls, intraoral NaCl elicited an inverted U-shaped function for both TRRs and intake. TRRs of chronic decerebrate rats varied with NaCl concentration. In contrast with controls, intake of NaCl did not differ from that of water for decerebrate rats. Data indicate that caudal brain-stem mechanisms are sufficient to control sucrose intake but not adequate for the concentration dependent intake of NaCl. Data indicate it is possible for taste-elicited oral motor responses to be dissociated from intake. Roles of taste and postingestive factors in sucrose and NaCl intake are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Lipid reactivity to stress: I. Comparison of chronic and acute stress responses in middle-aged airline pilots.

Lipids increase during psychological stress, but no studies have compared the effects of acute and chronic stressors on lipid responsivity in the same individuals. One hundred middle-aged men (n?=?92) and women (n?=?8) were examined during high chronic occupational stress, low chronic stress, and acute laboratory stressors. In addition to measures of perceived stress and affect, an extensive battery of lipid and lipoprotein measures was undertaken at each time point. Most lipid parameters were significantly increased during the chronic and acute stressors, although the responses to the different stressors were not consistently associated. For example, significant correlations among the chronic and acute stress responses were apparent for the apoproteins, but not for total, low density lipoprotein, or high density lipoprotein cholesterol. The factors and processes regulating these variables during stress may be different during acute and chronic stressors. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Visual stimulation facilitates penile responses to vibration in men with and without erectile disorder.

This study compared reflexogenic and psychogenic penile responses in men with and without erectile disorder. It was hypothesized that men with psychogenic erectile dysfunction respond minimally to vibrotactile stimulation. An enhancement of penile responses was expected when vibration was combined with erotic film. Patients were 50 men with psychogenic erectile dysfunction, 45 men with organic erectile dysfunction, and 50 sexually functional men. The combination of film and vibration resulted in stronger penile responses than the stimuli presented separately. Men with psychogenic erectile dysfunction and sexually functional men did not differ in responses to film and film-and-vibration conditions. As predicted, responses of the 2 groups were different in the vibration condition. Interpretations are provided in terms of attention and appraisal. The findings are relevant to the development of psychophysiological diagnostic procedures. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of alcohol administration on psychophysiological and subjective-emotional responses to aversive stimulation in anxiety-sensitive women.

Examined the effects of anxiety-sensitivity (AS) levels, and 1.00 ml/kg alcohol, on autonomic and subjective-emotional responses to aversive stimulation (i.e., noise bursts). Ss were 30 university women divided into 3 AS groups (high, moderate, and low), on the basis of Anxiety Sensitivity Index (ASI) scores. When sober, high-AS women provided higher emotional arousal ratings while anticipating the noise bursts than did low-AS women. Alcohol dampened the noise burst-anticipation ratings, particularly in the high-AS group. ASI scores were positively correlated with degree of sober skin conductance level (SCL) reactivity and with degree of alcohol dampening of SCL reactivity. Thus, high-AS women may use alcohol to normalize their anticipatory emotional and electrodermal overreactivity to threat. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

"Taste reactivity responses elicited by cocaine-, phencyclidine-, and methamphetamine-paired sucrose solutions": Correction to Parker.

Reports an error in "Taste reactivity responses elicited by cocaine-, phencyclidine-, and methamphetamine-paired sucrose solutions" by Linda A. Parker (Behavioral Neuroscience, 1993[Feb], Vol 107[1], 118-129). Table 1, on page 119, contains two errors. In the first section, the dose/route for the agent nicotine should read as follows: 1.2-2.0 mg/kg sc. In the second section, the dose/route for the agent morphine should read as follows: 2-80 mg/kg ip. Also, on page 121, paragraph 3, line 14, the parenthetical information after 40 mg/kg cocaine should read (40C; 2 × 20 mg/kg/3 cc). (The following abstract of the original article appeared in record 1993-24959-001.) The nature of flavor–drug associations produced by a range of doses of the reinforcing agents cocaine (5, 10, 15, 20, or 40 mg/kg, sc), phencyclidine (0.5, 2, 10, or 20 mg/kg, sc), and methamphetamine (2, 5, or 10 mg/kg, ip) were assessed by the taste reactivity (TR) test and the conditioned taste avoidance (CTA) test. Even at the highest doses tested, none of the agents produced aversive TR responding. At doses that produced equivalent-strength CTA, lithium did establish aversive TR responding. Results provide evidence that drugs that serve as reinforcers in other paradigms produce conditioned flavor avoidance that is not motivated by a conditioned dislike for the flavor. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Probing the folate-binding site of human thymidylate synthase by site-directed mutagenesis. Generation of mutants that confer resistance to raltitrexed, Thymitaq, and BW1843U89

Human thymidylate synthase (TS) contains three highly conserved residues Ile-108, Leu-221, and Phe-225 that have been suggested to be important for cofactor and antifolate binding. To elucidate the role of these residues and generate drug-resistant human TS mutants, 14 variants with multiple substitutions of these three hydrophobic residues were created by site-directed mutagenesis and transfected into mouse TS-negative cells for complementation assays and cytotoxicity studies, and the mutant proteins expressed and characterized. The I108A mutant confers resistance to raltitrexed and Thymitaq with respective IC50 values 54- and 80-fold greater than wild-type but less resistance to BW1843U89 (6-fold). The F225W mutant displays resistance to BW1843U89 (17-fold increase in IC50 values), but no resistance to raltitrexed and Thymitaq. It also confers 8-fold resistance to fluorodeoxyuridine. Both the kinetic characterization of the altered enzymes and formation of antifolate-resistant colonies in mouse bone marrow cells that express mutant TS are in accord with the IC50 values for cytotoxicity noted above. The human TS mutants (I108A and F225W), by virtue of their desirable properties, including good catalytic function and resistance to antifolate TS inhibitors, confirm the importance of amino acid residues Ile-108 and Phe-225 in the binding of folate and its analogues. These novel mutants may be useful for gene transfer experiments to protect hematopoietic progenitor cells from the toxic effects of these drugs.     

Individual differences in cardiac sympathetic control predict endocrine and immune responses to acute psychological stress.

Potential mechanisms coordinating individual differences in cardiovascular reactivity and endocrine and immune responses to acute psychological stress were examined. 23 young, healthy women performed a mental arithmetic challenge while measures of cardiovascular, endocrine, and immune function were assessed. Results revealed that the acute stressor was associated with changes in the cardiovascular, endocrine, and immune systems. More important, analyses revealed that individual differences in cardiovascular reactivity predicted stress-induced cortisol changes. Furthermore, cardiac sympathetic control, as indexed by preejection period, was specifically related to changes in natural killer cell activity. These results suggest that distinct physiological pathways are activated in response to acute psychological stress. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of heartbeat sound on the cardiac and behavioral responsiveness to tactual stimulation in sleeping preterm infants.

Assessed the effect of heartbeat sound on the heart rate and motor responses evoked by tactual stimulation during sleep. 30 preterm infants, 15 of whom had participated in a long-term intervention program, were tested one day in the presence of sound and another day in the absence of sound. During active sleep, the nonintervened Ss showed a significant cardiac response only in the presence of heartbeat sound. In this sleep state the sound also improved the discernibility of the motor responses for both groups of Ss by reducing spontaneous motor movements. During quiet sleep the sound had no effect on either cardiac or motor responsivity. Additionally, the sound influenced the duration of sleep states for both groups by markedly decreasing the duration of the lengthy 1st active sleep epoch and increasing the duration of the 1st quiet sleep epoch. (34 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Prolonged duration of craving, mood, and autonomic responses elicited by cues and imagery in smokers: Effects of tobacco deprivation and sex.

Increases in self-reported craving and changes in autonomic functioning are reliably elicited when smokers are exposed to tobacco-related stimuli compared with neutral stimuli. However, few studies have reported the time course of cue-elicited craving or have directly compared the effectiveness of smoking cues versus imagery to evoke a craving response. In addition to these two issues, we investigated the influence of tobacco deprivation and sex on craving, mood, and autonomic responses. Sixty cigarette smokers (30 men, 30 women) were tested in two counterbalanced sessions, one after overnight tobacco deprivation and one during ad libitum smoking. At each session, participants were exposed to four randomized experimental trials: smoking imagery, neutral imagery, smoking cues, and neutral cues. Tobacco craving and mood were assessed repeatedly and physiological measures were recorded continuously for 30 min after imagery or cue exposure. Compared with neutral trials, smoking cues and smoking imagery reliably increased tobacco craving, negative mood, heart rate, and blood pressure and decreased positive mood ratings. Changes were observed immediately after cue and imagery presentation and remained unchanged for 30 min. Responding was greater in the nondeprived condition, and cues elicited more robust responding than imagery for most measures. Women responded more robustly to smoking cues only in the nondeprived condition, whereas imagery evoked greater responses in men during both conditions. These findings provide new data on the time course, magnitude, and tobacco deprivation effects on elicited craving. Sex differences were dependent on stimulus type and deprivation condition. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Psychophysiological reactions to films by chronic schizophrenics: II. Individual differences in resting levels and reactivity.

Resting skin-resistance, heart-rate, and reactivity data to 1 of 2 tension-arousing films were obtained from 2 normal comparison groups and a sample of drug-free chronic schizophrenics. The schizophrenics were subdivided into 3 subsamples on the basis of the number of deviant associations given to a word-association test. The resting skin-resistance data failed to discriminate between normals and schizophrenics; however, meaningful differences were found among the schizophrenic subsamples such that increasing thought disturbance was associated with increasing basal resistance levels. Basal heart-rate data did indicate faster heart rate for all schizophrenic subsamples compared with both normal groups. Reactivity data also indicated different results for the 2 indexes. Skin-resistance indexes failed to indicate any differences between schizophrenics and normals or among the schizophrenic samples. 1 heart-rate index suggested less reactivity for schizophrenics than for normals. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Suppression of VMH-lesion-induced reactivity and aggressiveness in the rat by stimulation of lateral septum, but not medial septum or cingulate cortex.

32 male hooded rats made vicious with bilateral ventromedial hypothalamic lesions had bipolar electrodes implanted unilaterally in the lateral septum, medial septum, or cingulate cortex. Four days later, the Ss' reactivity and aggressiveness were evaluated 5 min before, during, and 5 min after stimulation at 20 muA (60 Hz, sine wave). Lateral septal stimulation suppressed reactivity and aggressiveness by almost 80% compared with pre- and poststimulation levels. Stimulation of neither the cingulate cortex nor the medial septum produced a change reliably different from that seen in unstimulated control Ss. Further tests with stimulation of the lateral septum at the 20 muA level showed that neither rewarding self-stimulation nor disruption of ongoing water drinking was produced. These results are congruent with evidence from lesion studies that the lateral septum normally acts to suppress reactivity and aggressiveness in the rat; they do not support previous suggestions that the medial septum is involved in the modulation of these behaviors. (30 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)