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Biomedical subjects

D D Krahn

Publications and source records attributed to D D Krahn.

53 records · Page 3Linked to original sources
PubMed1986

The effect of calcitonin gene-related peptide on food intake involves aversive mechanisms.

Calcitonin gene-related peptide (CGRP), the product of the calcitonin gene produced primarily in the central nervous system, has been shown to decrease food intake when administered intracerebroventricularly (ICV). Testing of CGRP (ICV) in both single bottle conditioned-aversion and differential starvation paradigms was done. In both paradigms, results using CGRP were consistent with those predicted for aversive agents. Therefore, CGRP apparently decreases feeding via aversive mechanisms.

Animals↗
PubMed1986

CRF antagonist partially reverses CRF- and stress-induced effects on feeding.

Exogenous corticotropin releasing factor (CRF) causes centrally mediated behavioral changes including decreased feeding and increased grooming. These behavioral changes are also seen in response to some stressors. However, the role of endogenous CRF in the behavioral response to stressors has not been investigated fully. We report below our findings on the behavioral effects of alpha-helical CRF (9-41), a recently discovered competitive antagonist of CRF-induced ACTH release. Alpha-helical CRF (9-41) partially reversed the decrement in feeding induced by CRF. Furthermore, the reduction in food intake due to restraint stress was partially reversed by alpha-helical CRF (9-41). These results indicate that changes in endogenous CRF release induced by the restraint stressor may play a role in stress-induced anorexia.

Animals↗
PubMed1986

Neuropeptides as regulators of consummatory behaviors.

The control of ingestive behavior involves a variety of neurotransmitters, including monoamines, peptides and amino acids. For the past decade many investigators have focused their research on the role that regulatory peptides play in eating behavior. Many peptides, including cholecystokinin, bombesin, calcitonin, corticotropin-releasing factor, neurotensin and somatostatin, have been reported to decrease the amount of food ingested by laboratory animals. In contrast, a relatively small number of peptides increase food intake. The present review describes the effects of these peptides on consummatory behaviors in various species and their sites of action.

Animals↗
PubMed1985

Peptides and feeding.

This report reviews the hypothesis that peptides play a role in appetite modulation, stressing that the available evidence is predominantly pharmacological and thus caution needs to be taken in assigning physiological significance at this time. Two peptide systems have been postulated--a peripheral satiety system, typified by the gastrointestinal hormone cholecystokinin and a central feeding system driven by the opioid peptides and neuropeptide Y. This review also discusses the putative role of peptides in the anorexia of aging, drinking elicited by feeding and as mediators of the autonomic effects seen in association with ventromedial hypothalamic lesions.

Aging↗
PubMed1985

Peptides as central regulators of feeding.

During the past decade there has been an increased awareness of the role peptides play as neuromodulators. In this article we review the available data on peptides as central regulators of food ingestion. We stress the possible problems of non-specific effects. We stress that whereas many peptides decrease feeding after central injection, only two families of peptides have been shown to increase feeding after central injection. These are the opioid family and the pancreatic polypeptide-neuropeptide Y family. The putative role of corticotropin releasing factor as the mediator of norepinephrine and serotonin effects on feeding is discussed.

Amphibian Proteins↗
PubMedDate not supplied

The severity of dieting and bingeing behaviors in college women: interview validation of survey data.

A combined survey and interview study was conducted to validate a categorical Dieting and Bingeing Severity Scale (DBSS), and to estimate the prevalence of eating disorders in young women. We hypothesized that assignment to the DBSS categories would be confirmed by clinical interviews such that interview-diagnosed eating disorders would be found with increasing frequency and severity at the upper end of the DBSS. Freshmen college women (n = 1367) completed a survey instrument addressing the frequency and severity of dieting, binge-eating, and other behaviors and attitudes related to weight control. Random stratified sampling procedures were used to select a subset of women (n = 306) from each DBSS category for structured clinical interviews for DSM-III-R (SCID). Survey respondents were assigned to one of six mutually exclusive DBSS categories: non-dieters (9% of sample), casual dieters (26%), moderate dieters (23%), intense dieters (21%), dieters at-risk (19%), and probable bulimia nervosa (2%). The DBSS effectively rank-ordered subjects according to the risk of having interview-diagnosed eating disorders. Women in the three most severe DBSS categories were significantly more likely to have current subthreshold and threshold level eating disorders, in particular bulimia nervosa and eating disorder not otherwise specified (EDNOS). The estimated prevalence of current bulimia nervosa was approximately 2% by both survey and interview methods. The prevalence of current EDNOS was 13%, more than six times greater than the prevalence of bulimia nervosa. The DBSS was found to be a reliable and valid measure of dieting and bingeing severity. The survey instrument may be useful in measuring the extent of, and changes in, pathological dieting in community-based samples of young women, and in studying comorbidity of dieting and bingeing severity with other psychiatric conditions including depression and substance use. The DBSS may also be useful in identifying risk factors associated with the onset of eating disorders.

Adolescent↗
PubMedDate not supplied

Obsessionality in eating-disorder patients: relationship to clinical presentation and two-year outcome.

Obsessionality and obsessive-compulsive symptoms have been regarded as important characteristics in the clinical presentation of the eating disorders. In this report, we examined the relation between obsessionality and the clinical presentation and outcome of a sample of eating-disordered patients. Self-rated obsessional symptoms, defined by the obsessive-compulsive subscale of the Symptom Checklist 90 (revised version), were compared with presenting clinical symptomatology, and scores on the Eating Disorder Inventory (EDI) and Beck Depression Inventory (BDI) in a sample of 110 consecutively evaluated women who met DSM-IIIR criteria for eating disorders. Forty patients were contacted for a follow-up investigation, 2 years after the initial evaluation. Higher obsessive-compulsive subscale scores at presentation were associated with more severe dieting, a greater number of psychiatric hospitalizations, and higher EDI, SCL-90R and BDI scores. Initial obsessive-compulsive scores did not predict the subsequent outcome of a sample of these patients in the community. However, elevated obsessive-compulsive scores obtained at follow-up were associated with the presence of lower body weight and more severe eating-disorder symptoms at that time. These results support the hypothesis that elevated obsessionality is associated with more severe eating disorder symptomatology. In addition, obsessional symptoms change along with those of the eating disorder, and their persistence may be associated with a poorer outcome.

Adolescent↗
PubMedDate not supplied

Effects of calcitonin gene-related peptide on food intake.

Recently, calcitonin gene-related peptide (CGRP), a product of alternative processing of RNA transcripts from the calcitonin gene, has been characterized. CGRP is present in a number of areas of the brain involved in modulating ingestive behaviors. We tested the effect of centrally administered CGRP on ingestive behaviors. ICV CGRP over a dose range of 1 to 10 micrograms suppressed food intake in 24 hr deprived rats and 20 and 10 micrograms decreased spontaneous nocturnal food intake. CGRP was less effective than calcitonin at suppressing food intake. Peripheral CGRP was less effective than centrally administered CGRP. Behaviorally, CGRP treated animals rested more, groomed less and ate less. Central CGRP (10 micrograms) did not alter circulating glucose levels. These results suggest that CGRP in high doses may be centrally active in regulating consummatory behaviors.

Animals↗
PubMedDate not supplied

Fat-preferring rats consume more alcohol than carbohydrate-preferring rats.

Rats with a genetic preference for alcohol (ETOH) have been found to consume more dietary fat then ETOH nonpreferring rats. We therefore hypothesized that rats selected on the basis of fat and carbohydrate (CHO) preferences would differ in ETOH intake. Patterns of macronutrient self-selection were determined by allowing rats to select diets from separate sources of CHO, fat and protein. Subsequently, CHO- and fat-preferring groups were formed. All rats were then returned to a lab chow diet and trained to drink ETOH (4-12%) during one hour of access per day. Food restriction was used only in the first three weeks of the procedure. On the final drinking sessions, water and ETOH were alternated on a daily basis. Fat-preferring rats consumed significantly more ETOH than water; CHO-preferring rats consumed approximately equal amounts of ETOH and water. Furthermore, fat-preferring rats consumed more ETOH than CHO-preferring rats. This study suggests that there may be a common mechanism underlying diet preference and oral intake of ETOH.

Alcohol Drinking↗
PubMedDate not supplied

The relationship between saccharin and alcohol intake in rats.

Male rats were given daily sessions during which a palatable saccharin solution was available. Based on intakes averaged over 3 days, groups with low, intermediate, or high intake of saccharin were formed. These rats were then given daily sessions in which alcohol (2-8%) or water were available. Initially, sessions were conducted with rats on a food restriction schedule; in later sessions, food was available ad lib. When rats were food restricted, there were no differences among the groups in terms of alcohol or water intake. When the food restriction schedule was discontinued, alcohol intake in the intermediate and high saccharin intake groups was generally higher than that of the low saccharin group. On the final series of alcohol sessions, the high saccharin group consumed significantly more 2% and 6% alcohol than the low saccharin group. These results are consistent with reports which have found that rats selected for high or low alcohol intake have corresponding high and low intakes of saccharin.

Alcohol Drinking↗
PubMedDate not supplied

Ethanol reinforcement and its relationship to saccharin preference in Wistar rats.

Forty rats were given a choice between 0.1% sodium saccharin and water. Based on their intakes, three groups of six rats representing high, intermediate, and low saccharin preferences were selected. These rats were reduced to 80% of their free-feeding weights. Ethanol was established as a reinforcer by use of a food-induced drinking procedure. Between-group differences were assessed based on response rates across acquisition sessions (0, 1, 2, 4, 5.7, 8%, w/v), a fixed-ratio series (1, 2, 4, 8, 1), and a concentration series (8, 5.7, 4, 2, 2, 4, 5.7, 8, 11.3, 16, 22.6, 32, 8%, w/v). In 29 of 32 conditions which were analyzed, the mean number of responses for ethanol was higher for the high saccharin preference group than for the low, and in 25 of 32 conditions, the intermediate group fell between the high and the low. However, there was considerable variability within groups across all conditions, such that mean between-group differences were not significant. This variability may be reduced by considering diet preferences in addition to saccharin preference. Nonetheless, these results offer limited support for the increasing body of evidence indicating a relationship between the factors mediating ethanol self-administration and those involving ingestion of palatable foods and fluids.

Animals↗
PubMedDate not supplied

Using interactive voice response technology and timeline follow-back methodology in studying binge eating and drinking behavior: different answers to different forms of the same question?

As part of a study of the relationship of binge eating, alcohol use, mood, and stressors, we compared the results of two forms of reporting on binge eating and drinking behavior. Forty-three first-year college women participated in an interactive voice response (IVR) study for 12 weeks. Participants answered computer-administered questions daily via IVR technology on number of eating binges and number of alcoholic drinks consumed. After 12 weeks, participants completed a Timeline Follow-back (TLFB) interview retrospectively for number of binges and drinks in the past 12 weeks. Results of this distally retrospective methodology (commonly used in drinking research and applied here also to binge eating) were compared to the results of daily IVR reporting. There was convergence across measures for drinking behavior, but divergence between IVR and TLFB for binge eating reports. TLFB reports underrepresented actual binge eating frequency, which calls into question the validity of applying this methodology to the assessment of binge eating.

Adolescent↗