PubMed HealthSearch

Biomedical subjects

N E Grunberg

Publications and source records attributed to N E Grunberg.

At least 19 recordsLinked to original sources

Effect of stress on oral morphine and fentanyl self-administration in rats.

The effect of immobilization stress (15 min/day) or no stress on oral morphine (0.25-0.5 mg/ml) or fentanyl (5-20 micrograms/ml) self-administration was examined in rats. Animals had access to a morphine or fentanyl solution for 4 days, followed by a single-choice day of access to the opioid solution and a separate water bottle. This 5-day cycle was repeated five times for 7 h/day in home cages. Morphine consumption and preference were assessed for an additional 30 days (i.e., six more cycles) in a subgroup of subjects. Plasma corticosterone levels in the stress groups indicated that the stress manipulation was effective. Over the course of the experiment, animals in the stress groups significantly increased their preference for the opioid solutions during choice days compared to nonstress controls. Morphine preference after 55 days was twice as high in the stress group (70% morphine/30% water) in comparison to controls (34% morphine/66% water). These results indicate that stress increases oral opioid self-administration in rats. Future directions and the implications of this work are discussed.

Administration, Oral

Effect of stress on hypothalamic insulin in rats.

Four experiments examined the effects of stress on hypothalamic insulin and plasma hormones in rats. Two hours daily of immobilization (IM) stress for 2 and 4 days resulted in an increase in hypothalamic insulin. In contrast, 15 min of daily IM over 13 days or 48 h of continuous signalled shock avoidance did not alter hypothalamic insulin. These findings are interpreted to indicate that changes in hypothalamic insulin are part of the stress response. Possible reasons for the different effects of time and paradigm on the hypothalamic insulin responses to stress are discussed. Plasma insulin and glucose levels were not responsive to any of the stressors. Brief acute stress caused increases in the stress-responsive hormones ACTH, corticosterone, and prolactin, as expected, and these responses attenuated or disappeared with repeated or longer stress exposures.

Adrenocorticotropic Hormone

The role of gender and taste class in the effects of stress on eating.

Participating in a laboratory study of the effects of stress on eating, healthy, nonsmoking men and women were shown a film about industrial accidents (stress condition) or a pleasant travelogue (control condition) and had access to sweet, salty, and bland snack food. Analyses of food consumption data revealed a significant interaction between sex of subject and the stress manipulation: Stress markedly and significantly decreased food consumption by men but resulted in some increased food consumption by women. Across the three food taste categories, men consistently ate less under stress than they did in the control condition. In contrast, women ate nearly twice as much sweet food and more bland food under stress than they did in the control condition, but these effects were not statistically significant. These results indicate that the relationship between stress and eating depends on the sex of the subject and may relate to type of food available. Contrasting generalizations about stress and eating reported in the archived literature can largely be reconciled by considering these interacting variables.

Adult

National working conference on smoking and body weight. Task Force 1: Mechanisms relevant to the relations between cigarette smoking and body weight.

Careful, comprehensive, and empirical observations provide the building blocks of the sciences, whereas theory and mechanisms provide the "cement" to hold the blocks together and serve as blueprints to direct future building. This article resulted from several days of discussion regarding theories that may underlie the relation between cigarette smoking and body weight and the relation between smoking cessation and body weight. The working group composed of social and biological scientists who addressed this assignment considered what is already known within the smoking and body weight literature and also considered relevant findings from studies of smoking or body weight regulation that have not directly addressed the interaction of these variables. As expected, we were successful at listing some of what is not known and what is worth knowing. We also tried to identify fruitful possibilities for research activity that might clarify mechanisms of action and eventually lead to theoretical development. Because we do not believe that the present state of our deliberations merits the label of theories, we decided, instead, to report the summary of these deliberations as potential mechanisms relevant to the relation between smoking and body weight.

Adult

Effects of nicotine on the acoustic startle reflex amplitude in rats.

The acoustic startle reflex was used to measure changes in sensorimotor reactivity in response to nicotine administration and cessation. Male rats received saline, 6 mg/kg/day or 12 mg/kg/day nicotine delivered subcutaneously by osmotic minipumps. The pumps delivered their contents during a 10-day period of implantation, after which time they were explanted. Animals were tested for startle reflex amplitudes using two levels of white noise bursts prior to pump implantation, on days 1 and 7 of nicotine or saline administration, and on several days following drug cessation. Nicotine produced a dose-dependent increase in startle amplitude during the period of administration that decreased during cessation. Results are interpreted in terms of nicotine's actions to enhance attentional processes.

Acoustic Stimulation

Gender, stress, and health.

Studying men and women and differences between them has long been a goal for researchers in health psychology. Recent advances in this endeavor, reflected in this special issue on the topic, have led to important information about the relationships between health and behavior. Of particular interest are possible differences in psychophysiological response, stress, and immune function. Clearly, more inclusive research strategies hold great promise for future scientific discoveries.

Disease Susceptibility

Conceptual and methodological considerations for tobacco addiction research.

The 1988 Surgeon General's Report on nicotine addiction has research and treatment implications. It focuses clinical treatments on tobacco use as an addiction and highlights the importance of examining actions of nicotine relevant to dependence. It also indicates the value of comparing the pharmacologic and behavioral processes underlying use of nicotine with other addictive drugs. This essay points out gaps that remain in our understanding of nicotine addiction. For example, the exact mechanisms underlying nicotine addiction are unknown. Also, the reasons for individual differences in initiation, withdrawal, relapse and reinforcing effects of tobacco use are not understood. Research designed to address these issues should be problem-driven and multidisciplinary. Parallel human and animal studies that include unconditioned as well as conditioned behaviors are particularly valuable.

Animals

Gender differences in tobacco use.

Gender differences in overall tobacco use clearly exist. In general, men are more likely to use tobacco products than are women. However, this simple generalization, ignoring type of tobacco products, time, and culture, masks many more interesting gender differences in tobacco use. There are pronounced gender differences in tobacco use of specific tobacco products within some cultures but not others. Yet these differences have changed across time, including narrowing and widening of this gender gap, depending on culture and tobacco product. This article addresses these issues and presents possible psychosocial, biological, and psychobiological explanations for these phenomena. In addition, the implications of these differences and ways to learn more about these important differences are discussed.

Adult

Effects of nicotine on body weight, food consumption and body composition in male rats.

The present study examined the effects of nicotine administration and cessation on body weight, food consumption, and body composition in rats. Administration of nicotine was associated with attenuated body weight gains and cessation was associated with accelerated body weight gains. Changes in fat composition paralleled changes in body weight, whereas changes in body water and protein did not. These results suggest that nicotine administration decreases body weight through its effects on fat stores in the body. After cessation of nicotine, body fat rapidly approached levels of control animals.

Adipose Tissue

Variations in food preference and consumption across the menstrual cycle.

There is some evidence that food consumption changes across the menstrual cycle. However, archived studies tend to rely on self-report data and do not differentiate among types of food eaten. The present laboratory study was designed to measure women's taste preferences and specific food consumption across the menstrual cycle. Women came into the laboratory, consumed everyday foods, and rated them on taste judgment scales. The foods were weighed before and after the tasting session to determine amount eaten. After the tasting session, subjects completed several questionnaires (e.g., measures of affect, restrained eating, menstrual cycle and menstrual symptoms). Physical measurements (e.g., height, weight) were taken at the end of the session. Sweet food consumption and preference ratings were significantly higher during the premenstrual period. Consumption and ratings of other foods did not differ. There were no differences in levels of mood, obesity, or restrained eating across the menstrual cycle. Low restraint was associated with reporting fewer menstrual symptoms, in general, and slightly better mood. These results support the idea that specific taste preferences change over the menstrual cycle, and that endocrinological factors could be involved in this phenomenon.

Adult

Smoking.

Explore the source record for details and available documents.

Forecasting

Smoking research: basic research, intervention, prevention, and new trends.

Smoking is a behavior that is influenced by a variety of factors that cut across methodologies, disciplines, and content areas within health psychology. The present article is designed to show the diversity and richness of smoking research by examining smoking from four perspective: basic laboratory research, intervention, prevention and deterrence, and new directions in smoking research. Methodologies that were derived from such varied sources as psychopharmacology, behavioral pharmacology, behavior therapy, clinical psychology, public health and health promotion, and social and developmental psychology have been used to study the smoking problem. The subject populations in these investigations ranged from animal models, to the individual smoker attempting to quit, to communities involved in health promotion and public health approaches. Future research should seek to provide new and improved examples of interdisciplinary research within the field of health psychology to multidisciplinary approaches from the basic and applied sciences.

Humans

Effects of nicotine on body weight in rats with access to "junk" foods.

The present experiment examined effects of nicotine on body weight of male and female rats when Oreo cookies, potato chips, laboratory chow, and water were available. Body weight and eating behavior were measured for 17-day periods before, during, and after nicotine or saline administration. There was an inverse relationship between nicotine and body weight. These effects were paralleled by changes in consumption of sweet foods. There were no effects of nicotine on salty or bland food consumption. Excessive gains in body weight after cessation of nicotine administration were greater for females than for males.

Animals

Sex differences in nicotine's effects on consummatory behavior and body weight in rats.

Nicotine administration and cessation have greater effects on body weight and eating behavior in female than in male rats. These generalizations are based on studies of body weight and eating behavior for 2-3 week periods before, during, and after nicotine administration. Therefore, the sex differences may reflect differences in sensitivity to nicotine or simply differences in the time course of nicotine's effects. The present research was designed to replicate these previous studies and to examine long-term effects of nicotine cessation on body weight. Nicotine or saline was administered SC to female and male Sprague-Dawley rats for 16 days. Body weight, food consumption, and water consumption were measured before, during, and after nicotine administration. In addition, body weight was measured for 4 months after cessation of nicotine. There was an inverse relationship between nicotine and body weight. Also, there was an inverse relationship between nicotine and general consummatory behavior for females but not for males. The body weight of females that had received nicotine were indistinguishable from controls up to 4 months after cessation of nicotine. The body weight of males that had received 12 mg nicotine per kg per day remained lower than controls.

Animals

The effects of acute exercise on subsequent cigarette smoking.

The present study was conducted to examine the effects of acute aerobic exercise on smoking behavior. On alternate days, 10 healthy young smokers were subjected to half an hour of sustained high exercise (about 56% of maximum work capacity) or of low exercise (about 28% of maximum, simulating normal daytime activity). During the high-exercise condition, there were pronounced increases in physiological markers of physical activity such as mean work, heart rate, and lactic acid as well as elevations in circulating hormones (norepinephrine, epinephrine, and immunoreactive beta-endorphin and cortisol) known to be affected by vigorous exercise. Despite a trend toward decreased desire for cigarettes after the high exercise condition, there were no differences in plasma nicotine levels following the smoking of a usual-brand cigarette 35 min later. The sustained effects of the two exercise conditions were also similar: plasma cotinine levels 24 hr later (reflecting nicotine intake over the entire exercise day) revealed no significant differences between high and low exercise.

Adult