Leucine‐enkephalin and Methionine‐enkephalin Produce Opposing Effects on Plasma Corticosterone Levels in Ether‐stressed Mice

Gibson, Alan; Hart, Stephen L.; Shabib, Amel

doi:10.1111/j.1476-5381.1980.tb09767.x

Cited by 16 publications

(5 citation statements)

References 8 publications

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“…Stengaard-Pedersen and L. -1. Larsson, manuscript in preparation) goes along with the observations of a differentiated release of the enkephalins (Corbett et al, 1980) and of a differentiated activity of Leu-and Met-enkephalin in at least one biological system (Gibson et al, 1980). The distribution of Met-and Leuenkephalin-immunoreactive nerve terminals in brain also agrees with the distribution of two types of opiate receptors with different sensitivity to the enkephalins (Goodman et al, 1980).…”

Section: Discussionsupporting

confidence: 61%

Immunocytochemical and ultrastructural differentiation between Met- enkephalin-, Leu-enkephalin-, and Met/Leu-enkephalin-immunoreactive neurons of feline gut

Li¹,

Stengaard-Pendersen²

1982

J. Neurosci.

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Selective immunocytochemical procedures, applied at the light and electron microscopical level, have resulted in the identification of three types of enkephalin-immunoreactive nerves in the feline gastrointestinal tract, including neurons containing either Met- or Leu-enkephalin immunoreactivity or those simultaneously storing both Met- and Leu-enkephalin immunoreactants. The three different types of enkephalin nerves show a similar distribution in the gut with the exception of the small arteries which frequently appear to be innervated only by Met-enkephalin-immunoreactive terminals. Electron microscopical identification using optimally fixed, osmicated, and contrasted tissue revealed ultrastructural differences between the three types of nerve terminals. Thus, the terminals contained variable proportions of large granular and large opaque p-type vesicles. Large granular vesicles were associated predominantly with Met-enkephalin immunoreactions. It is presently impossible to decide whether the different p-type vesicles reflect a continuous processing of a precursor contained within them or whether they are truly different in peptide content. Thus, granular vesicles had cores of either high or medium electron density. Medium electron-dense granular vesicles were sometimes difficult to distinguish from large opaque vesicles suggesting the existence of possible transitional forms. All types of enkephalin terminals also contained small clear ("cholinergic-like") vesicles which were not immunoreactive to enkephalins. These data indicate that multiple enkephalin precursors/enkephalin-containing peptides occur in the gut or, alternatively or additionally, that a common Met/Leu-enkephalin precursor is processed differently in different neurons.

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Section: Discussionsupporting

confidence: 61%

Immunocytochemical and ultrastructural differentiation between Met- enkephalin-, Leu-enkephalin-, and Met/Leu-enkephalin-immunoreactive neurons of feline gut

Li¹,

Stengaard-Pendersen²

1982

J. Neurosci.

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“…To confirm that this three-session exposure does cause a stress reaction, plasma corticosterone concentration was assessed 10 min after the end of the third ether exposure. A robust elevation in the steroid hormone was observed (32.8 lg/dl compared to 8.3 lg/dl for untreated controls, n = 4 each) as assayed by a commercial EIA immunoassay, indicating that our treatment paradigm also causes a typical stress reaction established for single-exposure procedures [16][17][18][19][20].…”

Section: Ether-induced Tau Phosphorylationmentioning

confidence: 73%

“…Ether‐induced sharp rise in plasma corticosterone concentration attains a peak in about 30 min and reverts to basal levels by about 2 h after ether exposure in rodents [16,17]. Ether anesthesia is thus considered to elicit a typical stress response, and has been employed in numerous neuroendocrinological studies of stress (e.g., [18–20]). Here, we take advantage of ether anesthesia to examine whether and how tau phosphorylation takes place in this peculiar situation of stress without motor activity.…”

Section: Introductionmentioning

confidence: 99%

Ether stress‐induced Alzheimer‐like tau phosphorylation in the normal mouse brain

2007

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Tau is reversibly hyperphosphorylated in the mouse brain by starvation or cold water swimming. Here, we report tau phosphorylation in the hippocampus of normal mouse after ether anesthesia, known to trigger typical stress reactions. Robust phosphorylation of tau was observed immediately and 10 min after ether vapor exposure at Ser202/Thr205 and Thr231/Ser235, sites typically phosphorylated in Alzheimer brains. The phosphorylation levels returned to baseline by 1 h. The most conspicuous and consistent change in the protein kinases studied was the inactivating phosphorylation of Ser9 of TPKI/GSK3b in close correspondence with tau phosphorylation. These findings show that tau phosphorylation is a rapid physiological process integral to stress response system, and suggest involvement therein of TPKI/GSK3b.

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“…In contrast to our previous study where a high CORT level was found upon chronic isolation [31] , in this study we found low levels of CORT in the blood serum of chronically stressed animals relative to the control. This discrepancy is likely due to the exclusion of ether anesthesia prior to sacrifice [32][33][34] . The current finding of low CORT in isolated animals is similar to the results of other authors showing HPA axis hypoactivity in stress conditions caused by isolation on either young animals or animals subjected to social isolation for shorter periods of time [35,36] .…”

Section: Discussionmentioning

confidence: 99%

Stress Type Dependence of Expression and Cytoplasmic-Nuclear Partitioning of Glucocorticoid Receptor, Hsp90 and Hsp70 in Wistar Rat Brain

Djordjević¹,

Adžić²,

Djordjević³

et al. 2009

Neuropsychobiology

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Chronic exposure to stress is associated with different behavioral and neurological syndromes including impaired excitability of nerve cells in hippocampus (HIPPO) and prefrontal cortex (PFC), regions of the brain that are important for adaptation. The successful adaptation to stress involves negative feedback at the level of the hypothalamic-pituitary-adrenal (HPA) axis provided by the glucocorticoid receptor (GR), which is a steroid-dependent transcription factor found in a heterocomplex with heat shock proteins Hsp90 and Hsp70. In Wistar rats, chronic social isolation leads to a significant decrease in serum corticosterone (CORT), probably due to alterations in the GR signaling pathway. We exploited this type of stress, alone or in combination with acute immobilization, to define changes in the expression level and compartmental distribution of GR, Hsp90 and Hsp70 in HIPPO and PFC. The results indicated that in acute and combined stress, when CORT was increased, GR was translocated to the nucleus in both brain structures. Under chronic stress, when CORT was below the control level, GR was retained in the cytoplasm of PFC, and evenly distributed between compartments in HIPPO. Simultaneously, heat shock proteins partitioning in HIPPO seemed to be mainly stress type-independent, while that of PFC was dependent on stress type. Thus, the stress type-specific responses of GR and heat shock proteins were mainly detected in PFC rather than in HIPPO of Wistar rats. The observed alterations in protein expression and cytoplasmic-nuclear partitioning of the GR, Hsp90 and Hsp70 proteins may be related to maladaptive response of the HPA axis under chronic stress.

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Leucine‐enkephalin and Methionine‐enkephalin Produce Opposing Effects on Plasma Corticosterone Levels in Ether‐stressed Mice

Cited by 16 publications

References 8 publications

Immunocytochemical and ultrastructural differentiation between Met- enkephalin-, Leu-enkephalin-, and Met/Leu-enkephalin-immunoreactive neurons of feline gut

Immunocytochemical and ultrastructural differentiation between Met- enkephalin-, Leu-enkephalin-, and Met/Leu-enkephalin-immunoreactive neurons of feline gut

Ether stress‐induced Alzheimer‐like tau phosphorylation in the normal mouse brain

Stress Type Dependence of Expression and Cytoplasmic-Nuclear Partitioning of Glucocorticoid Receptor, Hsp90 and Hsp70 in Wistar Rat Brain

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