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I Roske

Publications and source records attributed to I Roske.

At least 19 recordsLinked to original sources
PubMed2002

Effect of chronic intermittent immobilization stress on Fos-like immunoreactivity in rat brain and adrenal medulla.

The present study examined the influence of short- and long-term chronic intermittent immobilization stress throughout the brain and on the adrenal medulla of intact rats using Fos-like immunoreactivity (Fos-LI) as a marker of cellular activation. The effect of adreno-medullectomy on the central nervous system (CNS) response to chronic immobilization stress was also examined. It was found that control unoperated, unstressed rats had no Fos-LI cells in the brain or in the adrenal medulla. In intact rats, neither short term (1 week) nor long term (4 weeks) chronic intermittent immobilization stress produced significant increases in Fos-LI in the CNS compared with control animals. However, marked increase in the number of Fos-LI cells was observed in the adrenal medulla of animals stressed for 4 weeks compared with control, unstressed animals or those stressed for 1 or 2 weeks. In adreno-medullectomised rats, 4 weeks, but not 1 week, chronic immobilization stress produced significant increases in numbers of Fos-LI neurons in the paraventricular hypothalamic and supraoptic nuclei and the medial amygdala compared with intact animals stressed for a similar period of time. It is concluded that long term stress produces chronic Fos-LI in the adrenal medulla and that adreno-medullectomy increases the Fos response of the PVN, supraoptic nucleus and medial amygdala to long term stress.

Adrenal Medulla↗
PubMed1997

Alcohol induces formation of morphine precursors in the striatum of rats.

Dopamine-derived alkaloids, the tetrahydroisoquinolines (TIQs), are suspected to play a role in the pathogenesis of alcoholism. The present study describes the alcohol induced formation of the S-enantiomer of Tetrahydropapaveroline and Norcoclaurine in the rat brain. These compounds are of special interest since both were found as being intermediates in the biosynthesis of morphine in the opium poppy. The concentration of both TIQs were determined in different brain regions of Wistar rats after 6 and 18 months alcohol consumption ad libitum. Gas chromatography/mass spectrometry was used for the detection and quantification of the enantiomers. Tetrahydropapaveroline and norcoclaurine were detected only in the striatum of those rats which had consumed alcohol for 18 month, neither in other brain regions nor in any brain regions of the controls or the short term (6 month) alcohol treated rats. These findings and the fact that those tetrahydroisoquinolines were only detected in the striatum of the alcohol fed rats and were present only as the S-enantiomers suggest that an alcohol induced biosynthetic pathway exists in the mammalian brain.

Alkaloids↗
PubMed1995

Effects of voluntary ethanol ingestion on the POMC gene expression in the rat pituitary and on the plasma beta-endorphin content.

Studies investigating the influence of chronic ethanol treatment on the beta-endorphin content and the proopiomelanocortin (POMC) gene expression in the rat pituitary revealed contradictory results. Because of this we decided to start a more complex study to investigate the effects of isolation stress, chronic ethanol treatment and voluntary ethanol consumption on the POMC mRNA level in the rat pituitary. The immediately prepared total RNA from rat pituitaries was used in hybridization experiments (Northern- and Dot-blots). The results suggest a correlation between the POMC gene expression and the different fashions of 'living conditions' tested. So the POMC gene expression in long-term alcohol-treated animals was decreased supporting the theory of beta-endorphin deficiency in alcoholism. More interestingly, data obtained from the group of voluntary ethanol consumption suggest an inverse correlation between total ethanol ingestion and POMC gene expression. This indicates the importance of the method of ethanol administration. Consistent with a decreased POMC gene expression in the pituitary during chronic ethanol treatment are previous studies showing a decrease in the plasma beta-endorphin content in such situations. Surprisingly, in the present study the plasma beta-endorphin levels measured by radioimmunoassay were only slightly decreased in chronically ethanol-treated rats. This may be due to dysregulatory effects of ethanol on post-translational processing, degradation and/or release of beta-endorphin.

Alcohol Drinking↗
PubMed1991

Endogenous opioid dependence--a basic pathophysiological phenomenon of stress-induced and genetically fixed disturbances in adaptation--influence of substance P.

Disturbances in adaptive processes can be induced by chronic exposition to stress or can result from a genetical predisposition. Experimental data of chronically stressed Wistar rats and of spontaneously hypertensive rats (SHR) demonstrate a relation between a decreased level of substance P (SP) in adrenals, the existence of a dependence on endogenous opioid peptides and an increased regulatory level of blood pressure. The endogenous level of SP was determined by using a RIA. The dependence (physical) on endogenous opioid peptides was detected by using the method of "gut dependence". SP injection i.p. once a day for 4 d antagonized the dependence on endogenous opioid peptides and normalized the increased level of blood pressure in both animal models. Investigations on SHR had shown that the adaptive effect of SP on blood pressure and endogenous opioid dependence is bound to the premise of an acute stimulated endogenous opioid system at the moment of SP-application. Experimental findings suggest that different systems of opioid peptides take part in the etiopathogenesis of genetically predisposed hypertension of SHR and in stress-induced increase of blood pressure level of Wistar rats. The effect of SP on blood pressure and endogenous opioid dependence will be discussed as a result of the modulatory influence on the cholinergic-opioid-peptidergic interaction.

Adaptation, Physiological↗
PubMed1990

Possible role of substance P on regulation of pituitary-adrenal axis.

The effects of chronic immobilization stress on the physiological responses of male rats were studied. The results indicate that the SP-like immunoreactivity (SPLIR) is diminished in the adrenals and pituitary after chronic stress. In vitro noradrenaline (NA) release from adrenals was increased. The i.p. administration of SP during the stress procedure normalized the increased NA release in vitro indicating that the catecholamine secretion may be influenced by SP. On the other hand, in demedullated animals the SPLIR in the pituitary was partly reduced and the blood pressure was increased. In such animals chronic stress resulted in an increase of SPLIR in the pituitary in comparison with nonstressed, demedullated animals, but was without effect on the blood pressure. It is concluded that exposure to SP and the resulting decrease of noradrenaline release may have a significant influence on the pituitary-adrenal responsiveness to stress.

Adrenal Glands↗
PubMed1990

Stress-induced dependence on endogenous opioid peptides--a fundamental process in the pathophysiology of a disturbed adaptation--its influence by substance P.

Using previous findings of stress-induced disturbances in regulation of peripheral and central function within the general adaptation process and hints from the literature to a multiple participation of opioid peptides in adaptive processes, this paper represents experimental data which gives hints to a functional relation in the etiopathophysiology between the development of stress-induced dependence on endogenous opioid peptides and stress-induced disturbances in blood pressure regulation and to the adaptive effect of substance P within the peptidergic interaction with endogenous opioid peptides and its importance for the physiology or pathophysiology of adaptive processes.

Animals↗
PubMed1989

Stress-induced changes of the noradrenergic transmitter release in adrenals and the influence of substance P.

The paper presents results about the role of Substance P (SP) in stressful situations, especially on the spontaneous and nicotine-evoked noradrenaline (3H-NA) outflow in adrenal gland slices. Chronic stress increases the spontaneous as well as the stimulated 3H-NA outflow. SP applied i.p. during stress exposure inhibits the stress-induced elevation of the spontaneous and stimulated 3H-NA outflow. Application of SP direct to the superfusion solution influences the stimulated 3H-NA outflow but it does not change the spontaneous 3H-NA outflow in adrenal gland slices of stressed rats. The data support the hypothesis that SP modulates the transmitter release in adrenals during stressful situations.

Adrenal Glands↗
PubMed1988

Influence of adrenal demedullation on stress induced alterations within the general adaptation behaviour of August-rats.

Based on new theoretical aspects of functional participation of adrenal glands in adaptation process, resulting from supplement of Selye's stress concept by integration of peptidergic systems, stress related adaptation behaviour of sham operated and demedullated August-rats, characterized by a high stress-sensitivity, were investigated. To characterize the stress related behaviour the following parameters were investigated: Number of rats surviving the exposure, alterations of body mass, occurrence of ulcers and hyperaemia in stomach, blood pressure behaviour, organ mass of adrenals, pituitaries and hypothalami in total, SPLIR in adrenals, pituitaries, hypothalami in total as well as in their special nuclei areas of N. ventromedialis and N. lateralis. The following conclusions can be drawn from experimental results: The important role of adrenal medulla in regulation of adaptive processes is given by the interaction between of its catecholamine system and its regulatory system of peptides (substance P, Opioids). Whereas demedullation itself makes visible alterations which are connected with the loss of adrenal-catecholamine system, additional stressor exposition makes visible alterations connected with the loss of adrenal-regulatory system. Investigations show differences in the sensitivity of reaction against the influence of stressors between catecholamine system (more sensitive) and regulatory system of adrenal medulla of August-rats. Demedullation has a different influence on alterations induced by mild manipulation stress (activation of catecholamine system) and by immobilization (activation of regulatory system). The influence of manipulation stress is inhibited and the influence of immobilization is increased by demedullation. Results of this investigations refer to the existence of feedback relations between the adrenal medulla and pituitary as well as between adrenal medulla and hypothalamus. Furthermore there are indications, that the adrenal medulla takes part in the regulation of extraadrenal sympathetic activity. The experimental data give furthermore a hint for the existence of a high stress sensitivity of August-rats primary caused by the CNS.(ABSTRACT TRUNCATED AT 250 WORDS)

Adaptation, Psychological↗
PubMed1987

Influence of adrenal demedullation on stress-related behaviour in Wistar rats.

The influence of adrenal demedullation on stress-related behaviour (chronic immobilization) was investigated in respect to the following parameters and physiological processes: number of animals surviving the exposure, blood pressure behaviour, endogenous opioid system, pain sensitivity, endogenous level of substance P (SP) in pituitary and hypothalamus. The results showed that chronic immobilization stress and adrenal demedullation induce the same direction of alterations of physiological processes and parameters. This fact suggests the involvement of common regulatory mechanisms both in demedullation and chronic stress. An important process in this respect may be the induction of functional insufficiency of the adrenal medulla especially concerning the adrenal peptidergic mechanisms. Contrary to the sham operated rats the demedullated animals showed differences in their stress-related behaviour of parameters of adaptive regulatory processes. In rats with demedullation either no additional stress-related alterations of parameters in relation to the general adaptation processes were induced or the demedullation-induced alterations were antagonized partially or completely by chronic immobilization.

Adrenal Medulla↗
PubMed1987

Relationship of substance P to catecholamines, stress, and hypertension.

This paper presents results on the function of the adrenal medulla, especially the influence of substance P (SP) on the cholinergic-adrenergic interaction. Interconnections between the function of SP and its role in the development and maintenance of hypertension as well as its role in stress and adaptation are investigated. Substance P acts only in situations with an increased nervous activity, for example, after stress-induced activation of the pituitary-adrenal and sympathetic-adrenal axis. Substance P normalizes stress-induced disorders by maintaining homeostasis in the catecholamine system. The basis of the antistress effect is the modulation of both biosynthesis and release of catecholamines in the adrenals. The homeostasis effect of SP, as well as the antistress effect do not require the complete sequence of the molecule. The N-terminal SP fragment is fully active and has no side effects.

Adrenal Glands↗
PubMed1986

[The role of the N-terminal of the substance P molecule in its action in stress-related behavioral and blood pressure disorders].

Substance P and the N-terminal sequences SP1-9, SP1-7, SP1-4 and SP1-2 were investigated in their action on stress related alterations in blood pressure behaviour, stress related disturbances in conditioned reflex learning behaviour, alterations in the endogenous opioid system and on the blood pressure behaviour of spontaneously hypertensive rats. In addition the occurrence of vegetative effects such as acute hypertension and histamine release from mast cells were investigated. The results of this work show that N- and C-terminal sequences of the Substance P molecule differ in their actions. Whereas the vegetative effects decrease if the SP molecule is shortened from the C to the N-terminus the "antistress effect" of the Substance P molecule remains unchanged. Whereas the N-terminal tetrapeptide SP1-4 can be considered "essential" for the "antistress effect", the C-terminal pentapeptide of SP is considered to be the "essential sequence" for the vegetative effects. These results will open new possibilities for the synthesis of selectively acting SP-agonists.

Animals↗
PubMed1986

[Stress-induced changes in blood glucose level in normotensive Wistar-Kyoto rats (WKY) and spontaneously hypertensive rats (SHR) aged 13-14 and 26 weeks].

In normotensive WKY-rats and spontaneously hypertensive rats relations were investigated between the general stress related behaviour of adaptation and the blood glucose level under fasting condition. In respect to the level of blood glucose differences were existent specifically depending on age and strain. Compared with WKY-rats, spontaneously hypertensive rats on the same age had shown a higher stress related increase of blood glucose level. Furthermore an age depending increase of blood glucose level was found in both SHR and WKY-rats. These differences depending on strain and age are discussed including the further results about the influence of peptides on catecholamins and blood pressure regulation.

Animals↗
PubMed1985

Characterization of opioid dependence of isolated ileum of morphine dependent and of chronically stressed Wistar-Kyoto (WKY)-rats.

The opioid antagonist naloxone induced tonic contraction ("gut dependence") of isolated ilia of both morphine dependent WKY-rats and WKY-rats chronically stressed by immobilization. Morphine and met-enkephalin but neither dynorphine nor leu-enkephalin antagonized the naloxone induced "gut dependence" of isolated ilia obtained from morphine dependent WKY-rats. Met-enkephalin as well as dynorphine inhibited the "gut dependence" of chronically stressed rats; morphine and leu-enkephalin had no inhibitory effect. These differences between influences of different opioid peptides on "gut dependence" of morphine dependent rats versus "gut dependence" of rats chronically stressed by immobilization suggest that chronic stress induced or facilitated production of a different population of receptors.

Animals↗
PubMed1983

[Effect of substance P on blood pressure in rats, with and without hypokinetic stress].

The effect of substance P (SP) on blood pressure was studied in normotensive rats and in rats with hypokinesia-induced hypertension. To characterize the SP effect, the influence on the blood pressure value, intra-individual variation and interindividual changes was investigated. Whereas SP corrected the hypokinesia-induced changes (increased blood pressure, increase in the intra-individual blood pressure variations) in the stressed animals, no SP effect was observed in the normotensive control rats. These findings are discussed with a view to the assumed ability of SP to act as a regulatory peptide (regulide).

Animals↗
PubMed1983

[Behavior of blood pressure and substance P-like immunoreactivity (SPLIR) in plasma of rats with genetically fixed hypertension (SHR) under chronic intermittent immobilization].

The influence of chronic immobilization on blood pressure and on substance P-like immunoreactivity (SPLIR) in blood plasma was examined in 11-week-old male spontaneously hypertensive rats (SHR) and male normotensive Wistar Kyoto rats (WKY). In SHR chronic immobilization caused a stop of the genetically fixed development of hypertension at the level already reached. Also, SPLIR in blood plasma was lower compared with a SHR control group without immobilization. In WKY rats chronic immobilization has no influence on blood pressure and SPLIR. The observed variations in SPLIR and blood pressure under the influence of chronic immobilization is discussed in relation to a possible function of substance P in the development of hypertension.

Animals↗