|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
 |
Abstract |
|---|
Top
Abstract
Introduction
Materials & Methods
Results
Discussion
References
|
|---|
To study the effects of different types or intensities of stressors on immune reactivity in the lungs, we studied the ex vivo production of nitric oxide (NO) and IL-1
by alveolar macrophages (AM) after short exposure of rats to restraint stress or inescapable electric footshocks. Exposure to electric footshocks of various intensities resulted in an intensity-dependent decrease in NO production whereas the IL-1 production by
AM had increased. The secretory activity was similarly affected by restraint stress. When the time course
of electric footshocks on secretory functions of AM was studied, it was found that the effects on NO and
IL-1 production by AM were normalized 3 days after the stress induction, but reappeared when cells
were isolated 1 to 2 wk after stress exposure. Analysis of the effects of electric footshocks of various intensities on antibody production 10 days after the stress session and subsequent lung immunization with trinitrophenyl conjugated keyhole limpet hemocyanin (TNP-KLH), showed a footshock intensity-dependent response. Although exposure to stress induced an increase in plasma levels of adrenocorticotropic hormone (ACTH) and corticosterone (CORT), hormone levels did not differ between the various stress- exposed groups. This suggests that the observed stress effects on pulmonary immune functions were not
mediated by ACTH or CORT but point to a direct involvement of the autonomic nervous system.
| |
Introduction |
|---|
|
Top
Abstract
Introduction
Materials & Methods
Results
Discussion
References
|
|---|
Under normal conditions, local immune responses in the lungs to antigens in the ambient air are suppressed to prevent obstruction of pulmonary functions. To this end, the respiratory tract contains various exclusion barriers to prevent contacts between immune competent cells and the inhaled antigens (1). In addition, an active immune suppression exists, which is largely mediated by alveolar macrophages (AM) (2).
Recently we have described effects of mild inescapable
electric footshock stress on pulmonary immune functions.
After exposure of rats to this stressor and subsequent
intratracheal immunization with the T-cell dependent neo-antigen trinitrophenyl conjugated keyhole limpet hemocyanin (TNP-KLH), the primary and secondary humoral
responses in the lung were enhanced (5). Furthermore, AM isolated from animals exposed to electric footshocks
showed a marked increase in interleukin (IL)-1 and tumor necrosis factor (TNF)-
secretion in response to stimulation with bacterial endotoxin (LPS) ex vivo, whereas
the nitric oxide (NO) production was decreased (6). Based
on these data we suggested that short exposure to stressors
can modulate pulmonary immune functions by affecting the activity of AM and that in this way stress can contribute to the pathogenesis of asthma. However, from many
studies on the relationships between various stressors and
immune parameters it has become apparent that different
stressors can have different effects on immune parameters
(7, 8) depending on the nature (9), intensity (10), and time
delay between stressor and immune parameter studied
(11). In view of these confusing data, we wished to establish whether the observed effects of mild inescapable electric footshocks on pulmonary immune functions were limited to the particular conditions used or represent a more
general response to stressors. Therefore we compared the
effects of restraint stress and various intensities of electric
footshock stress on the capacity of alveolar macrophages
to produce IL-1, and NO ex vivo. In addition the time
course of the effects of stress was studied. As a model for a
more complex immunological response, the effect of various intensities of footshock stress was evaluated in immunization experiments.
| |
Materials and Methods |
|---|
|
Top
Abstract
Introduction
Materials & Methods
Results
Discussion
References
|
|---|
Animals
Specific pathogen-free male Wistar rats of 160-180 g were purchased from Harlan-CPB (Zeist, the Netherlands). Immediately after arrival the animals were housed two per cage in a laminar airflow unit under controlled light conditions in which the dark period was from 7:00 P.M.-7:00 A.M. Rats had free access to food and water. A 2-wk acclimatization period was allowed before experimental manipulations were initiated. In order to adjust the animals to experimental procedures, they were handled for 3 subsequent days before exposure to the stressor by picking them up twice daily for a few seconds. All experimental procedures were carried out between 9:00 A.M. and noon to minimize the influence of the diurnal cycle.
Stress, Anesthetization, and Immunization Procedures
Animals were exposed either to electric footshocks or to restraint stress. Animals which were subjected to inescapable scrambled electric footshocks (20 min, 4 times per min, 5 s, 0.25, 0.5, or 0.8 mA), were placed in one of two compartments of a Plexiglas shock box (24 cm long, 24 cm wide, and 32 cm high) with a grid floor. Rats were exposed to restraint stress by placing them in Plexiglas containers (16 cm long, 6 cm wide, 5 cm high) for 20 min. Animals were decapitated either immediately after the stress session or at various time intervals thereafter. Control animals stayed in their homecages until their decapitation. Trunk blood was collected, followed by isolation of alveolar macrophages.
When the effects of stress on primary immune functions were studied, animals were anesthetized immediately after the stress session with a mixture of ketamin (68 mg/kg/ip Aescoket; Aesculaap NV, Gent, Belgium) and xylazin (12 mg/kg/ip, Rompun; Bayer, Leverkussen, Germany). Anesthetized rats were fixed in an upright position and immunized intratracheally (i.t.) with 150 µg of the neoantigen TNP-KLH dissolved in 150 µl saline as described elsewhere (5). Control animals stayed in their homecages until their anesthezation and subsequent immunization. Ten days after immunization, all animals were decapitated and trunk blood was collected.
Hormone Assays
Trunk blood was collected in ice-cold heparinized tubes
and centrifuged (2,000 × g, 10 min, 4°C). Plasma was stored
at 
20°C until assayed. Concentrations of adrenocorticotropic hormone (ACTH) and corticosterone (CORT) in
plasma were measured by selective radioimmunoassay as
reported previously (12, 13).
Isolation and Culture of Alveolar Macrophages
Alveolar macrophages were obtained by bronchoalveolar
lavage as described earlier (6). In short, the bronchoalveolar lavage was performed by repeated instillation with a
total of 50 ml of Mg2+- and Ca2+-free Hank's buffered salt
solution containing 0.6 mM EDTA. Isolated cells within
the different experimental groups were pooled and washed
twice with RPMI 1640 (Gibco, Life Technologies, Breda, The Netherlands) containing 5% heat-inactivated fetal calf
serum (FCS; HyClone Laboratories, Logan, UT). Washed
cells were resuspended in culture medium (RPMI 1640, 10% heat-inactivated newborn calf serum [NBCS, Gibco],
2 mM L-glutamine [Gibco], Pen/Strep [Sigma, Chemical
Co., St. Louis, MO]). The isolated cells (> 95% alveolar macrophage by acid phosphatase staining, > 95% viable
by dye exclusion) were seeded in 24-well plates (Delta
plates; Nuclon, Kamstrup, Denmark) at a cell concentration of 5 × 105 cells in 500 µl culture medium, and were
cultured for 24 h with various concentrations of bacterial
endotoxin (E. coli 055.B5, Sigma). After culturing, media
were collected and centrifuged (2,000 × g; 15 min, 4°C),
divided in aliquots, and stored at 20°C until assayed.
Cytokine Determination
Concentrations of IL-1 in alveolar macrophage culture
supernates were measured by the use of a specific radioimmunoassay for rat IL-1 as described earlier (9, 13). As a
standard rat recombinant, IL-1 diluted in culture medium
was used. Radiolabelled rat IL-1 could not be displaced
by human recombinant IL-6 up to 100 µg/ml, human recombinant TNF- up to 25 µg/ml, human recombinant IL-1
receptor antagonist up to 20 µg/ml, recombinant human
IL-2 up to 24 µg/ml, recombinant murine interferon-
up
to 15 µg/ml, recombinant human IL-1 up to 20 µg/ml, and
LPS up to 100 µg/ml. The intra-assay variation was 6%.
The sensitivity of the assay was 100 pg/ml culture supernate.
Nitrite Assay
The nitrite concentration in culture supernates was measured by a colorimetric assay based on the Griess reaction described elsewhere in detail (14). Briefly, 50 or 100 µl culture medium aliquots were mixed with an equal volume of Griess reagent (1% sufanimide [Sigma], 0.1% napthylene diamine dihydrochloride [Sigma], 2% H3PO4 in water) and were incubated at room temperature for 10 min. The absorption at 550 nm was measured by use of a microtiter plate reader. NaNO2 (Merck, Darmstadt, Germany) dissolved in culture medium was used as a standard and culture medium as a blank.
Anti-TNP Antibodies
Ten days after immunization, animals were decapitated
and trunk blood was collected in polysterene tubes. After
coagulation, tubes were centrifuged (2,000 × g, 10 min,
4°C). Serum was stored at 20°C until assayed. The concentrations and isotype of specific anti-TNP antibodies in
sera were measured by using an enzyme linked immunosorbent assay (ELISA) as previously described (15).
Briefly, microtiter plates (Greiner, Alphen a/d Rijn, The
Netherlands) coated with TNP-ovalbumin were incubated
with twofold serum dilutions, followed by incubation with
isotype-specific monoclonal antibodies: mouse anti-rat
IgM peroxidase (Zymed, 1:3,000), goat anti-rat IgE (Nordic, 1:3,000), mouse anti-rat IgA (Serotec, 1:2,000), and
rabbit anti-rat IgG (ICN, 1:1,000). After washing, the wells were incubated with the appropriate conjugates, rabbit
anti-mouse peroxidase (Dako, 1:3,000), rabbit anti-goat
peroxidase (Dako, 1:2,000), or swine anti-rabbit peroxidase
(Dako, 1:1,000). Peroxidase was visualized using orthophenylenediamine-di-hydrochloride (OPD, Sigma) as a
substrate and the optical density of the reaction product
was measured at 492 nm.
Statistics
All data are expressed as mean and SEM. The plasma and
ACTH and CORT concentrations were evaluated by oneway analysis of variance (ANOVA) followed by the Student-Newman-Keuls (SNK) procedure. The effects of restraint and/or various intensities of electric footshocks on
nitric oxide, IL-1, and antigen-specific antibody production were analyzed with the use of a two-way ANOVA followed by the SNK procedure.
| |
Results |
|---|
|
Top
Abstract
Introduction
Materials & Methods
Results
Discussion
References
|
|---|
Acute Effects of Stressors on the Secretory Activity of Alveolar Macrophages Ex Vivo
To analyze the effects of restraint stress and of mild inescapable electric footshocks of various intensities on the
capacity of AM to secrete NO and IL-1, AM were isolated directly after exposure to the stressors for 20 min. In
concordance with earlier experiments (6), no differences
in isolated cell numbers and viability were observed between the experimental groups (data not shown). Alveolar
macrophages were cultured for 24 h with 10 ng/ml or 100 µg/ml of LPS, and nitrite and IL-1 concentrations in the
culture media were determined.
Exposure of the animals to electric footshocks of various intensities resulted in an intensity-dependent decrease
in NO and increase in IL-1 production of LPS-stimulated
AM (Figure 1), whereas secretion patterns of unstimulated cells showed no differences. As can be seen in Figure
1, restraint stress affected the LPS-induced production of
NO and IL-1 by AM in a similar manner. As depicted in Figure 2, exposure of rats to different stressors resulted in significant increments in ACTH and CORT levels in
plasma compared with control animals, but the stress-
exposed groups did not differ significantly from each other.
|
|
Effects of Electric Footshocks of Various Intensities on Immunization with TNP-KLH in the Lungs
To determine whether electric footshocks of various intensities affect the antigen-specific antibody production in a stimulus intensity-dependent manner, animals were exposed to 0.25, 0.5, or 0.8 mA electric footshocks and immediately immunized intratracheally with TNP-KLH. Ten days later rats were decapitated and the concentrations of anti-TNP-specific antibodies in serum were measured. As illustrated in Figure 3, the TNP-specific antibody production was higher at 0.5 mA than at 0.25 and 0.8 mA footshocks.
|
Long-term Effects of Electric Footshocks on the Secretory Activity of Alveolar Macrophages Ex Vivo
In order to study possible long-term effects of a single exposure to a short session of electric footshocks on the NO
and IL-1 production, animals were exposed to electric
footshocks of 0.8 mA (maximal effect) and were decapitated at various time intervals thereafter for the isolation
of AM, which were then studied in vitro as described
above. The stress-induced increase in IL-1 secretion and
decrease in NO production returned gradually to control
levels in 1 to 3 days (Figure 4). However, the observed stress effects reappeared after 1 wk for the nitric oxide
production and for IL-1 secretion 3 days to 2 wk after exposure to electric footshocks. Plasma concentrations of
ACTH and CORT were elevated immediately after the
stress session (t = 0), but never at the later days tested
(Figure 5).
|
|
| |
Discussion |
|---|
|
Top
Abstract
Introduction
Materials & Methods
Results
Discussion
References
|
|---|
Here we demonstrate that exposure of rats to two different types of stressors, mild inescapable electric footshocks
or physical restraint, induces rapid changes (within 20 min) in the ex vivo activity of AM. Stress leads to an increased IL-1 and decreased NO production. This inverse
relationship between IL-1 and NO production has recently been demonstrated using a NO synthase inhibitor
(16). This way we could demonstrate an autoregulatory function of NO produced by alveolar macrophages on
their IL-1 and IL-6 secretion, but not on the production
of TNF- (16). However, as shown elsewhere, stress also
enhances TNF- production by AM, but not the secretion
of IL-6 (6). This indicates that, in addition to autoregulatory influences by NO, cytokine production in AM after
stress is also affected via other pathways.
In view of the important regulatory role of alveolar macrophages in T-cell activation in the lungs, it can be envisaged that the observed effects of stress on AM are pivotal in the changes observed in specific antibody production. However, because many cell types and tissues are involved in the initiation and development of antibody responses, stress can affect this process at many sites. This may explain why the response of isolated AM is linearly dependent on the intensity of the stimulus whereas, in contrast, the primary immune response to TNP-KLH showed an optimum at an intermediate intensity. A linear relationship with the intensity of the stressor and effects on a single cell type has been described for the proliferative capacity of T-cells isolated from lymphoid organs and whole blood (10, 17).
The shock intensity-dependent changes in secretory activity of AM are not significantly reflected in the plasma
levels of ACTH and CORT. This suggests that other stress-related hormones and/or the autonomic nervous system
are involved. In recent years it has become clear that the
lung is highly innervated. An extensive parasympathetic
innervation of the respiratory tract has been observed and
in addition, receptors for (nor)adrenalin are abundantly present in the airways (20, 21). Furthermore, many neuropeptides and their receptors have been demonstrated in
immunologically important compartments of the lung (22-
28). A possible involvement of the ANS is in line with reported findings that AM express adrenoceptors (30, 31)
and that stimulation of the -adrenoreceptor can enhance
the TNF- production by peripheral macrophages (31). Further experiments are now in progress to study the involvement of the autonomic nervous system on immune
functions in the lungs.
Intriguingly, the observed stress-induced changes in secretory activity of alveolar macrophages observed directly following exposure to the stressor seem to disappear within 3 days, but reappear after 1-2 wk. Recently we reported long-term effects of a single footshock session on behavioral, autonomic, and neuroendocrine responsiveness to environmental stimuli, that required 2 wk to fully develop (32). These observations were associated with delayed and long-lasting phenotypic changes of hypothalamic CRH neurons, and this finding is considered to be indicative for increased reactivity (35, 36). Apparently single exposure to an aversive stimulus can induce long-term functional changes in the hypothalamic area, a region which is considered as the center of integration of adap-tive responses to stress (37). We hypothesize that stress- induced functional changes in the hypothalamic area can affect the output of the autonomic nervous system to the lungs, resulting in the reappearance of stress-induced changes in secretory activity of alveolar macrophages. The long-term effects of stress on functional activities of alveolar macrophages reported herein imply that, even after a prolonged period of time, stress may contribute to the onset or severity of inflammatory processes in the lung, such as asthma.
| |
Footnotes |
|---|
Abbreviations: adrenocorticotropic hormone, ACTH; alveolar macrophages, AM; corticosterone, CORT; enzyme linked immunosorbent assay, ELISA; fetal calf serum, FCS; trinitrophenyl conjugated keyhole limpet haemocyanin, TNP-KLH.
(Received in original form November 28, 1995 and in revised form September 25, 1996).
Acknowledgments: The writers thank Mr. R. Binnekade and Mr. J. Brevé for performing the ACTH and CORT assays and Mr. N. Nordsiek for reproducing the figures.
| |
References |
|---|
|
Top
Abstract
Introduction
Materials & Methods
Results
Discussion
References
|
|---|
1. Bice, D. E., and G. M. Shopp. 1988. Antibody responses after lung immunization. Exp. Lung Res. 14: 133-155 [Medline].
2. Thepen, T., C. McMenamin, B. Girn, G. Kraal, and P. G. Holt. 1992. Regulation of IgE production in pre-sensitized animals: in vivo elimination of alveolar macrophages preferentially increases IgE responses to inhaled allergen. Clin. Exp. Allergy 22: 1107-1114 [Medline].
3. Thepen, T., C. McMenamin, J. Oliver, G. Kraal, and P. G. Holt. 1991. Regulation of immune responses to inhaled antigen by alveolar macrophages: differential effects of in vivo alveolar macrophage elimination on the induction of tolerance versus immunity. Eur. J. Immunol. 21: 2845-2850 [Medline].
4.
Thepen, T.,
N. Van Rooijen, and
G. Kraal.
1989.
Alveolar macrophage
elimination in vivo is associated with an increase in pulmonary immune response in mice.
J. Exp. Med.
170:
499-509
5. Persoons, J. H. A., K. Schornagel, T. Thepen, F. Berkenbosch, and G. Kraal. 1995. Increased specific IgE production in lungs after the induction of acute stress in rats. J. Allergy Clin. Immunol. 95: 765-770 [Medline].
6. Persoons, J. H. A., K. Schornagel, J. Breve, F. Berkenbosch, and G. Kraal. 1995. Differential effects of acute stress on the production of cytokines and nitric oxide by rat alveolar macrophages. Am. J. Respir. Crit. Care Med. 152: 619-624 [Abstract].
7. Moynihan, J. A., and N. Cohen. 1992. Stress and immunity. In Stress and Disease Processes. Lawrence Erlbaum Associates, Inc., Publishers, Hillsdale, NJ.
8. Grossman, C. J. 1989. Stress and the immune response: interactions of peptides, gonadal steroids and the immune system. In Frontiers in Stress Research. Hans Huber Publishers, Toronto. 181-190.
9. Berkenbosch, F., D. W. Wolvers, and R. Derijk. 1991. Neuroendocrine and immunological mechanisms in stress induced immunomodulation. J. Steroid Biochem. Mol. Biol. 40: 639-647 [Medline].
10.
Keller, S. E.,
J. M. Weiss,
S. J. Schleifer,
N. E. Miller, and
M. Stein.
1981.
Suppression of immunity by stress: effects of a graded series of stressors on
lymphocyte stimulation in the rat.
Science
213:
1397-1400
11.
Schleifer, S. J.,
S. E. Keller,
M. Camerino,
J. C. Thornton, and
M. Stein.
1983.
Suppression of lymphocyte stimulation following bereavement.
JAMA
250:
374-377
12.
Van Oers, J. W. A. M., and
F. J. H. Tilders.
1991.
Antibodies in passive immunization studies: characteristics and consequences.
Endocrinology
128:
496-503
13.
Derijk, R.,
N. Van Rooijen,
F. J. H. Tilders,
H. O. Besedovsky,
A. Del Rey, and
F. Berkenbosch.
1991.
Selective depletion of macrophages prevents
pituitary-adrenal activation in response to subpyrogenic, but not to pyrogenic, doses of bacterial endotoxin in rats.
Endocrinology
129:
330-338
14. Ding, A. H., C. F. Nathan, and D. J. Stuehr. 1988. Release of reactive nitrogen intermediates and reactive oxygen intermediates from mouse peritoneal macrophages. J. Immunol. 141: 2407-2412 [Abstract].
15. Delamarre, F. G. A., E. Claassen, and N. Van Rooijen. 1989. Primary in situ immune response in popliteal lymph nodes and spleen of mice after subcutaneous immunization with thymus dependent or thymus independent (type 1 and type 2) antigens. Anat. Rec. 223: 152-157 [Medline].
16. Persoons, J. H. A., K. Schornagel, F. H. Tilders, J. de Vente, F. Berkenbosch, and G. Kraal. 1996. Alveolar macrophages autoregulate IL-1 and IL-6 production by endogenous nitric oxide. Am. J. Respir. Cell Mol. Biol. 14: 272-278 [Abstract].
17. Lysle, D. T., M. Lyte, H. Fowler, and B. S. Rabin. 1987. Shock-induced modulation of lymphocyte reactivity: suppression, habituation and recovery. Life Sci. 41: 1805-1814 [Medline].
18. Moynihan, J. A., G. Brenner, D. Koota, S. Breneman, and R. Ader. 1990. The effects of handling on antibody production, mitogen responses, spleen cell number and lymphocyte subpopulations. Life Sci. 46: 1937-1944 [Medline].
19. Hardy, C., J. Quay, S. Livnat, and R. Ader. 1990. Altered T lymphocyte response following aggressive encounters in mice. Physiol. Behav. 47: 1245-1251 [Medline].
20.
Nijkamp, F. P.,
F. Engels,
P. A. J. Henricks, and
A. J. M. Van Oosterhout.
1992.
Mechanisms of -adrenergic receptor regulation in lungs and its implications for physiological responses.
Physiol. Rev.
72:
323-367
21. Nadel, J. A., and P. J. Barnes. 1984. Autonomic regulation of the airways. Annu. Rev. Med. 35: 451-467 [Medline].
22. Barnes, P. J.. 1986. Neural control of human airways in health and disease. Am. Rev. Respir. Dis. 134: 1289-1314 [Medline].
23.
Barnes, P. J..
1984.
The third nervous system in the lung: physiology and
clinical perspectives.
Thorax
39:
561-567
24. Richardson, J. B.. 1983. Recent progress in pulmonary innervation. Am. Rev. Respir. Dis. 128: S65-S68 [Medline].
25. Said, S. I.. 1988. Vasoactive intestinal peptide in the lung. Ann. NY Acad. Sci. 527: 450-464 [Medline].
26. Wiedermann, C. J., K. Sertl, and C. B. Pert. 1987. Neuropeptides and the immune system: substance P receptors in bronchus-associated lymphoid tissue of rat. Ann. NY Acad. Sci. 496: 205-210 [Medline].
27. Barnes, P. J., J. N. Baraniuk, and M. G. Belvisi. 1991. Neuropeptides in the respiratory tract. Part I. Am. Rev. Respir. Dis. 144: 1187-1198 [Medline].
28. Barnes, P. J., J. N. Baraniuk, and M. G. Belvisi. 1991. Neuropeptides in the respiratory tract. Part II. Am. Rev. Respir. Dis. 144: 1391-1399 [Medline].
29. Hjemdahl, P., K. Larsson, M. C. Johansson, A. Zeterlund, and A. Eklund. 1990. Beta-adrenoceptors on human alveolar macrophages isolated by elutriation. Br. J. Clin. Pharmacol. 30: 673-682 [Medline].
30.
Liggett, S. B..
1989.
Identification and characterization of a homogeneous
population of 2-adrenergic receptors on human alveolar macrophages.
Am. Rev. Respir. Dis.
139:
552-555
[Medline].
31.
Spengler, R. N.,
R. M. Allen,
D. G. Remick,
R. M. Strieter, and
S. L. Kunkel.
1990.
Stimulation of -adrenergic receptor augments the production of macrophage-derived tumor necrosis factor.
J. Immunol.
145:
1430-1434
[Abstract].
32. Van Dijken, H. H., J. A. M. Van der Heyden, J. Mos, and F. J. H. Tilders. 1992. Inescapable footshocks induce progressive and long-lasting behavioural changes in male rats. Physiol. Behav. 51: 787-794 [Medline].
33. Van Dijken, H. H., J. Mos, J. A. M. Van der Heyden, and F. J. H. Tilders. 1992. Characterization of stress-induced long-term behavioural changes in rats: evidence in favor of anxiety. Physiol. Behav. 52: 945-951 [Medline].
34. Van Dijken, H. H., D. C. E. De Goeij, W. Sutanto, J. Mos, E. R. De Kloet, and F. J. H. Tilders. 1993. Short inescapable stress produces long lasting changes in the brain-pituitary-adrenal axis of adult male rats. Neuroendocrinology 58: 57-64 [Medline].
35. De Goeij, D. C. E., R. Kvetnansky, M. H. Whitnall, D. Jezova, F. Berkenbosch, and F. J. H. Tilders. 1991. Repeated stress-induced activation of corticotropin releasing factor neurons enhances vasopressin stores and colocalization with corticotropin-releasing factor in the median eminence of rats. Neuroendocrinology 53: 150-159 [Medline].
36. Tilders, F. J. H., E. D. Schmidt, and D. C. E. De Goeij. 1993. Phenotypic plasticity of CRF neurons during stress. Ann. NY Acad. Sci. 697: 39-52 [Medline].
37. Morgane, P. J., and J. Panksepp. 1980. The Handbook of the Hypothalamus, Vol. 3, part 1, 2: Behavior. Marcel Dekker, New York.
This article has been cited by other articles:
 |
|
 |
|
  H. Suzuki, M. Kawasaki, H. Ohnishi, H. Otsubo, T. Ohbuchi, A. Katoh, H. Hashimoto, T. Yokoyama, H. Fujihara, G. Dayanithi, et al. Exaggerated Response of a Vasopressin-Enhanced Green Fluorescent Protein Transgene to Nociceptive Stimulation in the Rat J. Neurosci., October 21, 2009; 29(42): 13182 - 13189. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. Levenstein The Very Model of a Modern Etiology: A Biopsychosocial View of Peptic Ulcer Psychosom Med, March 1, 2000; 62(2): 176 - 185. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 E. Broug-Holub, J. H. A. Persoons, K. Schornagel, S. C. Mastbergen, and G. Kraal Effects of Stress on Alveolar Macrophages: A Role for the Sympathetic Nervous System Am. J. Respir. Cell Mol. Biol., November 1, 1998; 19(5): 842 - 848. [Abstract] [Full Text]
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Proc. Am. Thorac. Soc. | Am. J. Respir. Crit. Care Med. |