Opioid Systems and Stress

Przewłocki, Ryszard

doi:10.1007/978-3-642-77540-6_12

Cited by 14 publications

(6 citation statements)

References 151 publications

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“…Endogenous opioid peptides may integrate these responses to stress (Boissy, 1995). Opioids are involved in many responses to stress (Przewlocki, 1993), regulate various endocrine systems, including the hypothalamic-pituitary-adrenocortical (HPA) axis, and underlie the phenomenon of stress-induced analgesia. Rushen and Ladewig (1991) detected an opioid-based stressinduced analgesia in restrained pigs and found that naloxone (a generalized opioid antagonist with a strong affinity for µ-opioid receptors) increased HPA responses and vocalization in response to restraint.…”

Section: Introductionmentioning

confidence: 99%

Opioid peptides and behavioral and physiological responses of dairy cows to social isolation in unfamiliar surroundings.

Rushen¹,

Boissy²,

Terlouw³

et al. 1999

Journal of Animal Science

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To test whether endogenous opioid peptides are involved in the behavioral and physiological responses of cattle to stress, 12 Holstein cows were either placed in social isolation in unfamiliar surroundings for 15 min or remained in their home stalls, either with or without naloxone treatment, following a Latin square design. Vocalizations (judged as high or low frequency), defecation/urination, and heart rate were recorded, latency to respond to local thermal stimulation of the leg by means of a laser was measured to detect pain sensitivity, and blood was sampled and assayed for cortisol concentrations. Naloxone in the home stall increased cortisol concentrations and tended to reduce response latencies to the laser but did not induce vocalization. Social isolation increased the incidence of high-frequency vocalization and of defecation/urination, heart rate, cortisol concentrations, and response latencies to the laser. Prior administration of naloxone increased the incidence of low-frequency vocalization in isolation, but it had no effect on heart rate or on responses to the laser and only limited effect on cortisol concentrations when the cows were isolated. Brief periods of social isolation in unfamiliar surroundings seem to be stressful to cows, as indicated by increased heart rate, hypothalamic-pituitary-adrenocortical axis activity, and vocalization. Isolation also reduces pain sensitivity, suggesting a stress-induced analgesia. However, we found no evidence that naloxone-sensitive opioid receptors were involved in these responses.

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Section: Introductionmentioning

confidence: 99%

Opioid peptides and behavioral and physiological responses of dairy cows to social isolation in unfamiliar surroundings.

Rushen¹,

Boissy²,

Terlouw³

et al. 1999

Journal of Animal Science

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“…Furthermore, a number of experiments have demonstrated that stress can modify passive and active avoidance response behaviors (2 -6). In this regard, it is well understood that opioid peptides are closely involved in stress circuits, being released under stressful conditions (7). Endogenous opioids have also been implicated as mediators of stress-induced analgesia (SIA) (8)(9)(10).…”

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confidence: 99%

Effects of Footshock-, Psychological- and Forced Swimming-Stress on the Learning and Memory Processes: Involvement of Opioidergic Pathways

Jódar

Takahashi

Kaneto

1995

Japanese Journal of Pharmacology

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ABSTRACT-Modulation of learning and memory acquisition, retention and retrieval in the one trial passive avoidance learning task in mice by three inescapable stresses, i.e., footshock (FS), psychological (PSY) and forced swimming (SW) were investigated. Pre-, post-training and pre-test FS-stress (2 mA, 0.2 Hz, 1 sec for 30 min) and pre-training PSY-stress (communication box, 5 min) resulted in enhanced test latencies. On the contrary, SW-stress (201C, 5 min) immediately or 1 hr after training impaired retention latencies that tended to recover after 2 hr post-training SW-stress, suggesting that at least 2 hr are required to consolidate newly acquired information. In contrast, pre-stress naloxone (Nx), which did not affect FSand PSY-stress induced facilitatory effects, returned to control levels the impaired retention latencies induced by SW-stress. Taken collectively, these results imply the involvement of an opioid-dependent mechanism in the modulation of memory by SW-stress and non-opioid in the case of FS-and PSY-stress. Furthermore, they suggest that different mechanisms are involved in stress-induced memory modifications and the production of stress-induced analgesia (SIA) since in the latter, FS and PSY but not SW stress produce Nx-sensitive ontinn~i ', r~tinn

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“…The general stimulatory role that opiods have on Prl release is believed to be mediated by the hypothalamic-dopaminergic tuberoinfundibular system (see review by Cella, Locatelli and Miiller, 1993). The hypothalamic release of dopamine can be inhibited during a period of stress as a consequence of enhanced release of endogenous opioid peptides (see review by Przewlocki, 1993). This in turn will result in the pituitary secretion of Prl being enhanced when an animal is subjected to stress (Raud, Kiddy and Odell, 1971).…”

Section: Discussionmentioning

confidence: 99%

Naloxone evokes a nutritionally dependent LH response in post partum beef cows but not in mid-luteal phase maiden heifers

Sinclair¹,

Broadbent²,

Hutchinson

1995

Anim. Sci.

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Data from two experiments are reported which test the hypothesis that nutrient and/or dry-matter intake and body condition may interact to modify hypothalamic opioidergic activity and thus influence the pulsatile release of LH during the early post-partum period and during the oestrous cycle. Experiment 1 involved 16 multiparous, twinsuckling beef cows, and was a 2 X 2 X 2 factorial design in which the factors were level of post-partum energy intake (80 v. 130 M] metabolizable energy (ME) per day), the digestible undegradable protein (DUP) content of the post-partum diet (14 v. 31 g/kg dry matter), and treatment with either 200 mg or 400 mg naloxone hydrochloride. Blood samples were collected at 15-min intervals for 4h at weeks 4 and 7 post partum. Naloxone was administered intravenously after the eighth sample. Experiment 2 involved 16 cyclic maiden heifers and was also arranged in a factorial manner, with two levels of body condition at the start of the experimental period (2-50 and 3-16 units) and two levels of energy intake thereafter (40 and 80 MJ ME per day). Seven blood samples were collected at 15-min intervals on 4 days consecutively during the mid-luteal phase of the oestrous cycle. On the first 2 of these 4 days naloxone was administered, whilst on the last 2 days a gonadotropin-releasing hormone agonist (buserelin; GnRH) was administered, both after the fourth sample. Plasma from both experiments was assayed for LH and prolactin (Prl).In experiment 1, cows on 130 MJ ME per day returned to oestrus and ovulated earlier than cows on 80 M] ME per day (44-5 v. 55-0 days; s.e.d. = 3-93; P < 0-05). At week 4 post partum the proportional increase in plasma LH following naloxone challenge was greater for cows on 130 M] ME per day than cows on 80 M] ME per day (1 -38 v. 1-12; P < 0-05), but the converse was true at week 7 (1-15 v. 1-68; P < 0-05). Cows on the high DUP diet required a higher dose of naloxone to elicit an LH response. Few heifers in experiment 2 exhibited an LH response to naloxone. In contrast, there were significant dietary treatment effects on the LH response to GnRH (P < 0-01). Relatively thin heifers on 40 M] ME per day exhibited the lowest proportional increases in plasma LH to GnRH challenge, whereas heifers on 80 MJ ME per day and given the higher dose of GnRH produced the greatest plasma LH responses. Mean Prl concentrations before and after feeding in experiment 2 were respectively 13-2 and 10-2 ng/l (P < 0-01). Suckled cows given a high energy diet during the early post-partum period can overcome the opioid mediated block on LH release and resume oestrous cycles earlier than cows given a low energy diet. LH would appear to be inhibited by a non-opioid mechanism in mid-luteal phase heifers. Total pituitary reserves ofLH may be influenced by the animals nutritional status.

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Opioid Systems and Stress

Cited by 14 publications

References 151 publications

Opioid peptides and behavioral and physiological responses of dairy cows to social isolation in unfamiliar surroundings.

Opioid peptides and behavioral and physiological responses of dairy cows to social isolation in unfamiliar surroundings.

Effects of Footshock-, Psychological- and Forced Swimming-Stress on the Learning and Memory Processes: Involvement of Opioidergic Pathways

Naloxone evokes a nutritionally dependent LH response in post partum beef cows but not in mid-luteal phase maiden heifers

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