Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “DEFECATION”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,423 records · Page 79Linked to original sources
PubMed1985

Dissociation between adrenocorticotropin and corticosterone responses to restraint after previous chronic exposure to stress.

The effect on emotional reactivity produced by a model for chronic stress in which different types of acute stresses were randomly combined for 29 days was studied in adult male rats. Chronically stressed rats showed a slight decrease in body weight gain and an increase in relative adrenal weight. Chronic stress did not modify defecation rate but reduced exploratory activity in the holeboard. Neither basal nor acute-stress induced levels of adrenocorticotropin (ACTH) were modified by previous chronic stress. Likewise, basal corticosterone levels were similar in both groups. However, corticosterone response to acute restraint stress was higher in chronically stressed than in control rats. The mechanisms underlying the dissociation between ACTH and corticosterone as well as its possible implications are discussed.

Adrenocorticotropic Hormone↗
PubMed1975

Effects of the lesion of the postcommissural part of the septum on the behavior of the rat.

The effects of the lesion of the postcommissural part of the septum on behavior of the rat has been studied. Results may be summarized as follows. An increase in the exploratory behavior in the open field which decreases rapidly; a decrease in the number of defecations in this test and a decrease in time leaving a dark environment for exploration. In the shuttle box test, no facilitation of the acquisition, but a permanent and quite significant increase in the intertrial activity has been found. We conclude that the lesions tend to decrease the emotivity of the subjects. An interpretation on the basis of the species -- specific defensive reactions explains the transitory and permanent effects of the lesions on the spontaneous activity.

Aggression↗
PubMed1987

Effects of early separation of young rats from the mother on their open-field behavior.

Changes were studied in the open-field behavior of young rats prematurely separated from their mothers at different ages. Premature separation from the mother on days 15 and 18 of life increased their fear or emotional behavior, as measured by the amount of defecation and locomotor activity. The changes in rats' open-field behavior were due to the absence of the mother rather than to an inadequate food supply after the day of separation.

Aging↗
PubMed1991

Infantile (handling) stimulation and behavior in young Roman high- and low-avoidance rats.

The effect of infantile handling stimulation on exploratory and emotional behavior of Roman high- and low-avoidance (RHA/Verh and RLA/Verh) weanling rats was investigated. Postnatally handled and nonhandled, 4-week-old males and females from both psychogenetically selected lines were exposed to a hexagonal tunnel maze, including an illuminated central arena. Postnatal handling increased exploratory behavior and decreased emotional reactivity as expressed by increased entries into the central arena and a reduction in defecations in both lines of rats. These effects were more pronounced in the RLA/Verh rats. In agreement with earlier studies using nonselected adult rats, the females of both lines (especially those from the RHA/Verh line) were more sensitive than males to the positive influences of early stimulation.

Animals↗
PubMed1995

Stress-induced changes in regional monoamine metabolism and behavior in rats.

Groups of adult, male, Sprague-Dawley rats were subjected to either restraint at room temperature or cold restraint at 4 +/- 1 degree C for 2 h. Spontaneous motility, measured immediately after the stress, was decreased and defecation scores were increased in the cold restraint group but not in the restraint group. The rats were then sacrificed and prefrontal cortex, nucleus accumbens, and striatum dissected out. The levels of dopamine (DA), dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA), serotonin (5-HT), and 5-hydroxyindole acetic acid (5-HIAA) were measured in these areas by high performance liquid chromatography (HPLC) with electrochemical detection. DA levels were decreased in the prefrontal cortex (-68%), nucleus accumbens (-40%), and striatum (-76%) of the cold restraint group when compared to the controls. DA levels were decreased only in the prefrontal cortex of the restraint rats (-31%) when compared to the controls. The cold restraint group also had increased levels of DOPAC in the prefrontal cortex (+66%) and nucleus accumbens (+65%) and increased levels of HVA in the prefrontal cortex (+43%) when compared to the control group. Our results therefore indicate that cold restraint activates DA metabolism in the prefrontal cortex, nucleus accumbens, and striatum while restraint activates DA metabolism in the prefrontal cortex alone. Thus, cold restraint may be a more potent stressor than restraint alone.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1991

Manometric characterization of rectal dysfunction following radical hysterectomy.

Bladder dysfunction thought to be due to partial denervation has been described following radical hysterectomy. Some patients experience acute and chronic rectal dysfunction characterized by difficulty with defecation and loss of defecatory urge. To define this abnormality, anorectal pressure profiles were examined in 15 patients with Stage I carcinoma of the cervix before and after radical hysterectomy. Profiles were done using standard anorectal manometry with a water-infused system. In all patients preoperative manometric profiles were normal; postoperative studies were abnormal in all patients. Features seen include altered relaxation of the internal sphincter, increased distension needed to trigger relaxation, and decreased rectal sensation; external sphincters and resting internal sphincters were unchanged. Postoperatively, 12 patients reported problems with rectal function. A physiologic defect is definable in patients undergoing radical hysterectomy; this suggests disruption of the spinal reflex arcs controlling rectal emptying. These physiologic abnormalities correlate with the clinical symptomatology experienced by some patients. Continuing definition and evaluation of management options in this situation should be useful in developing effective therapy for rectal dysfunction following radical hysterectomy.

Defecation↗
PubMed1979

Attenuation of saccharin neophobia by melatonin.

Administration of Melatonin has been reported to decrease emotionality in the rat as indexed by the defecation response. The present experiment was designed to examine whether Melatonin would attenuate the neophobic response to a novel solution. It was found that Melatonin significantly increased the rat's consumption of a novel saccharin solution suggesting that the emotionality/arousal produced by the intake of this solution was attenuated.

Animals↗
PubMed1982

Open-field emotional reactivity and alcohol intake in rats.

The relationship between open-field emotional reactivity and alcohol intake was investigated. Randomly selected, high and low open-field defecation (OFD) groups from each of the MNR, MR and RCA genetic lines of rats were used. No functional relation between OFD as a measure of emotional reactivity and alcohol intake was found. Differences in alcohol intake among genetic lines were confirmed. It is concluded that emotional reactivity is a mediating process related independently to both OFD and alcohol intake.

Alcohol Drinking↗
PubMed1985

Low level lead effects on activity under varying stress conditions in the developing rat.

The study was designed to determine whether lead ingestion by nursing rats would affect the way offspring reacted to the stress inducing properties of the test environment both as juveniles and mature rats. Dams were exposed to diets with 0.0, 0.2, 0.4 or 1.0 percent by weight metallic lead. Mean blood-lead levels of pups at weaning were 4, 25, 36 and 55 micrograms/100 ml of blood respectively. The stress factor was varied by (1) changing the test apparatus, i.e., forcing rats to occupy an open field or allowing the animal to be a free agent in the start box of a T-maze; (2) testing rats under a longitudinal and a cross-sectional experimental design to vary familiarity with the apparatus; and (3) comparing behavior in the presence or absence of noise. Reactivity was assessed by examining the inter-and intra-session pattern of ambulations and defecations. Analysis of data revealed that lead treated rats demonstrated the greater response to stress. This response was generally dose related although recovery was dependent upon the test applied and measures taken. The findings provide a conceptual framework to account for varied results across previous studies.

Aging↗
PubMed1989

Alteration of the effects of caffeine by prenatal stress.

We examined the effect of prenatal stress exposure on sensitivity to caffeine using behavioral and physiological measures. Pregnant rats were handled 5 minutes daily from the 14th to 21st day of gestation. Male offspring were tested when 60 days of age in a modified open field apparatus 30 and 90 minutes after injection with caffeine (0, 10, 30 mg/kg). Caffeine increased crossover frequency and duration at the 10 mg/kg dose. Rearing frequency and duration were increased by the 10 mg/kg dose while the 30 mg/kg dose was ineffective. Gnawing was increased by caffeine, especially 90 minutes postinjection. Headpoke activity was decreased by caffeine treatment. Caffeine had no effect on defecation and urination. Gnawing activity was increased by caffeine in prenatally nonstressed animals, but was depressed in prenatally stressed animals. Prenatal stress increased sensitivity to caffeine on corner activity and rearing. The other measures were not affected differentially by prenatal stress exposure. Rectal temperature was depressed 0.75 degrees C in both prenatally stressed and nonstressed animals, by the 30 mg/kg dose of caffeine. Thus, our results indicate that prenatal stress affects sensitivity to caffeine in the adult offspring. However, the long-term effects of prenatal stress exposure are dependent on the measures employed.

Animals↗
PubMed1991

Influence of various acute stressors on the activity of adult male rats in a holeboard and in the forced swim test.

The effects of various acute stressors on the activity of adult male rats in a holeboard and in the forced swim test were studied. When tested immediately or 24 h after 1 h exposure to noise, restraint in tubes or tail shock, no changes in either defecation rate or activity in the holeboard were observed. In contrast, immediately after 1 h immobilization in wood-boards, a reduction of the number of areas crossed and the number of head-dips was found. The inhibitory effect of immobilization on head-dips persisted 24 h later. The behavior of the rats in the forced swim test was classified into three categories: struggling, mild swim and immobility. The changes in behavior were critically dependent on the type of stressor, and more specifically on its intensity, that was evaluated with three different physiological parameters (serum prolactin, corticosterone and glucose levels). Thus, if tested immediately after stress, noise did not alter the response of the rats, restraint in tubes and tail shock-reduced immobility, and the latter stressor increased mild swim. In the second experiment, immobilization in wood-boards reduced struggling. Twenty-four hours after stress, noise, restraint in tubes or tail shock were without effect, but immobilized rats showed increased immobility and reduced mild swim activity. The present data clearly indicate that behavior of rats in a holeboard and in a forced swim situation are not related, and that acute stress could have a differential effect on the various categories of behavior in a forced swim situation.

Animals↗
PubMed1991

MDMA produces a conditioned place preference and elicits ejaculation in male rats: a modulatory role for the endogenous opioids.

Methylenedioxymethamphetamine (MDMA) can produce a conditioned place preference (CPP) among rats. The ability of MDMA to produce a CPP was assessed while some rats were under the influence of naltrexone, 56 mg/kg, given 4 h before conditioning. Naltrexone attenuated MDMA's ability to produce a CPP without completely blocking MDMA's effects. Having noticed previously the production of seminal plugs by rats receiving MDMA, the presence of seminal plugs was recorded across the 8 days of conditioning. Roughly half of the rats receiving 6.3 mg/kg of MDMA left plugs during the conditioning period, while over two-thirds of those receiving a combination of MDMA and naltrexone left plugs. A second study, assessing further doses of MDMA, tabulated the drug's effects on the production of seminal plugs across 3 h. Besides eliciting ejaculation, MDMA also led to increased urination and defecation and a loss of body weight. These results support suggestions that the endogenous opioids modulate the reinforcing properties of stimulant drugs and affect male sexuality.

3,4-Methylenedioxyamphetamine↗
PubMed1992

Effects of physostigmine on novelty-related location preferences.

Novelty-related location preferences and activity in an exploration box were recorded for male and female Wistar albino rats following intraperitoneal injections of 0.04 or 0.08 mg/kg of either physostigmine or neostigmine. Although rearing was reduced by the highest dose of both drugs and ambulation was reduced by the same dose of neostigmine, neither agent affected the significant preferences for novelty that typified all subjects. In a second experiment designed to assess the effects of 0.08 mg/kg of the two drugs administered during rather than after confinement to the familiar half of the apparatus, neostigmine reduced rearing, walking, and ambulation while increasing defecation, but physostigmine did not affect any response. While some minor motor impairment may have arisen from its peripheral effects, the lack of changes in novelty-related location preferences failed to support facilitation of either novelty avoidance or habituation by physostigmine suggested in previous studies.

Animals↗
PubMed1993

Further characterization of the behavioral effects of peripherally administered corticotropin-releasing factor in guinea pigs.

Guinea pig pups were either not injected (NI) or given SC injection of either saline vehicle (SAL) or 14 micrograms of corticotropin-releasing factor (CRF). In an isolation test, mean number of vocalizations and several measures of locomotor activity were markedly lower for CRF pups than for NI or SAL controls. CRF pups defecated less than did SAL pups. No differences were found among conditions for self-grooming. Behavioral freezing was shown by only two pups in the entire study. Significantly more CRF pups displayed piloerection, eye-closing, and a characteristic crouched stance than did controls. In a defensive withdrawal test, no differences among conditions were found for the proportion of pups entering a darkened chamber or for the latency to enter the chamber; however, CRF pups entered the chamber significantly fewer times during the 60-min test than did controls. There were no differences among conditions in the distance swum or number of turns made in a forced-swim test. These results replicate our earlier findings that peripheral injection of CRF suppresses vocalizing and a measure of locomotor activity in isolated guinea pig pups and identifies a number of additional behavioral effects. Of central interest here, the results indicate that the suppression of vocalizing and locomotion during isolation is not due to an increase in competing stress-related behavior or to diminished motor capacity.

Aggression↗
PubMed1993

Effect of conditioned fear stress on serotonin metabolism in the rat brain.

The effects of electric foot-shock stress (EFS) and conditioned fear stress (CFS) on serotonin [5-hydroxytryptamine (5-HT)] metabolism in seven various brain regions of the rat were studied by measuring tryptophan, 5-HT and 5-hydroxyindoleacetic acid (5-HIAA). EFS for 30 min increased tryptophan levels in almost all brain regions but did not change 5-HT levels in any regions. It increased 5-HIAA levels in the medial prefrontal cortex (mPFC), nucleus accumbens, and amygdala. CFS (exposure to an environment paired previously with foot-shock) increased defecation and induced freezing behavior. It failed to change tryptophan and 5-HT levels in any brain regions but increased 5-HIAA level only in the mPFC. In contrast to EFS, which increased 5-HT metabolism in several other brain regions, increased metabolism of 5-HT was especially marked in the mPFC after CFS, regarded as psychological stress.

Animals↗
PubMed1995

Effects of prolonged selenium deficiency on open field behavior and Morris water maze performance in mice.

Neurobehavioral effects of prolonged Se deficiency were evaluated using ICR mice. Dams were fed Se-deficient or Se-adequate diet starting at 4 weeks before conception through the suckling period. After weaning, offspring of both groups were given the same diet as their dams were given. The behavior of these offspring was evaluated with open field apparatus (OPF) and Morris water maze. In OPF, Se-deficient females exhibited less locomotor activity, more defecation, and less entry to the center square areas than did the control females. No such difference was found in males. In the Morris maze, Se-deficient females showed slight but significant impairment during the initial phase of the trials. The behavioral changes in OPF and the maze might have been due to an altered reactivity to a novel environment, although this possibility needs further confirmation. The obtained data showed that the altered behavior was unlikely to be due to the changes in thyroid hormones. Mechanism of these behavioral effects is discussed in relation to possible neurochemical changes induced by Se deficiency.

Animals↗
PubMed1993

Synaptic function is impaired but not eliminated in C. elegans mutants lacking synaptotagmin.

Synaptotagmin is an abundant synaptic vesicle-associated protein proposed to be involved in calcium-mediated neurotransmitter release. Our molecular and genetic results demonstrate that, although synaptotagmin is required for the proper function of the presynaptic nerve terminal in C. elegans, some neurotransmitter release persists in synaptogamin mutants. In C. elegans neurons, synaptotagmin is localized to regions known to be rich in synapses and appears to be associated with synaptic vesicles. Mutants defective in the synaptotagmin gene, called snt-1, exhibit severe behavioral abnormalities that are characteristic of deficiencies in synaptic function, including severe locomotion, feeding, and defecation defects. The mutants are defective in exocytosis, since they accumulate acetylcholine, and are resistant to cholinesterase inhibitors, but they nevertheless remain sensitive to cholinergic receptor agonists. In spite of these exocytic defects, snt-1 mutants are capable of coordinated motor movements, indicating that the mutants do not have a complete block of neurotransmitter release.

Amino Acid Sequence↗
PubMed1981

Amitriptyline and scopolamine in an animal model of depression.

Adult male Sprague-Dawley rats were subjected to acute (95 dB white noise) or chronic stress, or their combination. In comparison with unstressed controls, stressed rats were more active upon several measures of open field activity. A history of chronic stress eliminated the acute stress induced activation. Concurrent treatment of chronically stressed rats with amitriptyline or scopolamine, or with a combination of both drugs resulted in selective behavioral improvement (i.e., in motor activity, latency, defecation) for amitriptyline and combined treatment rats, with significant restoration of the normal behavioral response. Scopolamine however was only marginally effective. A higher dose of scopolamine proved effective, but only with a marked disruption of baseline activity. Examination of plasma corticosterone titers indicated that chronic stress induced an elevation of basal levels and that this was reversed by amitriptyline, scopolamine, and combined drug treatment. Thus while behavioral depression and elevated corticosteroids may covary they are not identically mediated.

Amitriptyline↗