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Influence of acute stress on function of polymorphonuclear leukocytes
160
Pharmacological Research, Vol . 26, Supplement 2, 1992 INFLUENCE OF ACUTE STRESS ON FUNCTION OF POLYMORPHONUCLEAR LEUKOCYTES .
M .C . Cassone and A . Pisterna Institute of Pharmacology and Pharmacognosy,University of Turin, Turin . Key words : stress, PMNs, superoxide, chemiluminescence, 5-HT .
it has become abundantly clear that interactions between immune system and central and/or peripheral nervous systems exist : the linkage is media ted by the synthesis, release or turnover of neurotransmitters that are capable of modulating immune responses ; immune system, moreover, may release signal molecules that may interact with SNC functions (1) .Behavioral factors may cause significant alterations of immune system (2) ; experime n tal and clinical evidences showed that stressful situations can influence changes in immune function and induce or exacerbate the progression of phisical illness . The effects of acute exposure of a variety of stressors (e .g . cold exposure, immobilization, restraint, footshock, exercise, etc .) on immune responses were studied, in animals, by various researchers . A stressful condition for the animal is restraint and immobilization : influence on T-cells was found (3) . Since phagocytic cells play also a major role in the host defense mechanism against infections and/or neoplastic diseases, our purpose was to investigate the effects of acute restraint and immobilization on polymorphonuclear leukocytes (PMNs) . Materials and methods . Male Wistar rats (200-220 g) were maintained in a controlled environment with food and water available ad libitum . The rats were randomly assigned to control and acute restraint groups (named stre s sed) . Acute restraint and immobilization was for 5 min in a suitable plastic tube . Approximately 24 h after the treatment, controls and stressed rats were killed by decapitation and trunk blood collected in heparinized tubes . Purified preparations of PMNs were obtained by a Dextran sedimentation of red cells, followed by a Ficoll-Paque gradient centrifugation . Suitable su spensions of PMNs were tested for superoxide production and chemiluminescence emission . 02 production was monitored spectrophotometrically (A = 550 ran), by the SOD-inhibitable reduction of ferricytochrome c ; as stimulus opsonized zymosan (STZ),was used, time of incubation was 20 min . Luminol-dependent CL was measured in a Packard Picolite 6112 Lumincmeter . PMN suspension in fetal calf serum was activated with STZ ; light emission was recorded for 35 min at 5 min intervals . -4 Influence of serotonin (1x1O M) on 02 production and CL emission was also studied . Serotonin was chosen for its inhibitory effects on phagocytosis (4) for its immunomodulatory properties and the role in stressful situations (5) . The significance of the differences between treated and control PMNs, in presence or absence of serotonin, was evaluated by the Student t test Results and discussion . The stressful condition led to decreased OZ produ c tion in neutrophils stimulated by STZ and the inhibitory effect of 5HT on
1043-6618/92/26110160-02/$03 .00/0
© 1992 The Italian Pharmacological Society
161
Pharmacological Research, Vol. 26, Supplement 2, 1992
02
generation is greater in stressed (88%) than in control PMNs (48%)
(Ta-
ble I) . Table I - Superoxide anion production (nmol/10 6 cells/20 min) in control and stressed rat PMNs in absence and presence of 5HT . + 5HT (1x10 -4 M) 53 .2 t 2 .9 35 .5 + 3 .3
Controls Stressed
27 .4 t 3 .1 6 .5 t 1 .1
In the luminol-enhanced CL system the result is higher for stressed than control PMNs (Figure 1) . The effect of 5BT result in an inhibition of the CL emitted by PMNs .
Figure 1 : Time trace of CL emitted from PMNs of stressed and control rats ( •- •s tressed, •--- • stressed + 5HT, o-o controls, o---o controls + 5HT)
3 3 . w ( [tea/ 3as, EOI x s)uno3) io
The results in
02
production and CL emission seemed to be not in agreement,
but it may be hypothesize that enhancement of CL in stressed PMNs might be related to a greater availability of MPO content or to an increased activ i ty of MPO-H2 2 -halide system ; luminol-induced CL is really an indicator of intracellular and extracellular activity of the MPO system of the neutrophil . References 1 . Ader R ., Felten D ., Cohen N . Interactions between the brain and the immu ne system . Ann . Rev . Pharmacol . Toxicol . 1990 ; 30 : 561-602 . 2 . Ader R ., Cohen N ., Felten D . Brain, behavior and immunity . Brain . Behav . Immun . 1987 ; 1 : 1-6 . 3 . Teshina H ., Sogawa H ., Kihara H . in Jankovic B .D . et al . Neuroimmune interactions : Proc . 2nd Int . Workshop on Neuroimmunomodulation . In New York Academy of Sci . New York 1987 : 459 . 4 . Cassone M .C ., Fundar6 A ., Molinengo L . Action of 5-hydroxytryptamine, hi stamine and methergoline on phagocytosis . Pharmacology, 1974 ;11 :199-206 . 5 . Van de Kar L .D . Neuroendocrine pharmacology of serotonergic neurons . Ann . Rev . Pharmacol . Toxicol . 1991 ; 31 : 289-320 .
Pharmacological Research, Vol . 26, Supplement 2, 1992 INFLUENCE OF ACUTE STRESS ON FUNCTION OF POLYMORPHONUCLEAR LEUKOCYTES .
M .C . Cassone and A . Pisterna Institute of Pharmacology and Pharmacognosy,University of Turin, Turin . Key words : stress, PMNs, superoxide, chemiluminescence, 5-HT .
it has become abundantly clear that interactions between immune system and central and/or peripheral nervous systems exist : the linkage is media ted by the synthesis, release or turnover of neurotransmitters that are capable of modulating immune responses ; immune system, moreover, may release signal molecules that may interact with SNC functions (1) .Behavioral factors may cause significant alterations of immune system (2) ; experime n tal and clinical evidences showed that stressful situations can influence changes in immune function and induce or exacerbate the progression of phisical illness . The effects of acute exposure of a variety of stressors (e .g . cold exposure, immobilization, restraint, footshock, exercise, etc .) on immune responses were studied, in animals, by various researchers . A stressful condition for the animal is restraint and immobilization : influence on T-cells was found (3) . Since phagocytic cells play also a major role in the host defense mechanism against infections and/or neoplastic diseases, our purpose was to investigate the effects of acute restraint and immobilization on polymorphonuclear leukocytes (PMNs) . Materials and methods . Male Wistar rats (200-220 g) were maintained in a controlled environment with food and water available ad libitum . The rats were randomly assigned to control and acute restraint groups (named stre s sed) . Acute restraint and immobilization was for 5 min in a suitable plastic tube . Approximately 24 h after the treatment, controls and stressed rats were killed by decapitation and trunk blood collected in heparinized tubes . Purified preparations of PMNs were obtained by a Dextran sedimentation of red cells, followed by a Ficoll-Paque gradient centrifugation . Suitable su spensions of PMNs were tested for superoxide production and chemiluminescence emission . 02 production was monitored spectrophotometrically (A = 550 ran), by the SOD-inhibitable reduction of ferricytochrome c ; as stimulus opsonized zymosan (STZ),was used, time of incubation was 20 min . Luminol-dependent CL was measured in a Packard Picolite 6112 Lumincmeter . PMN suspension in fetal calf serum was activated with STZ ; light emission was recorded for 35 min at 5 min intervals . -4 Influence of serotonin (1x1O M) on 02 production and CL emission was also studied . Serotonin was chosen for its inhibitory effects on phagocytosis (4) for its immunomodulatory properties and the role in stressful situations (5) . The significance of the differences between treated and control PMNs, in presence or absence of serotonin, was evaluated by the Student t test Results and discussion . The stressful condition led to decreased OZ produ c tion in neutrophils stimulated by STZ and the inhibitory effect of 5HT on
1043-6618/92/26110160-02/$03 .00/0
© 1992 The Italian Pharmacological Society
161
Pharmacological Research, Vol. 26, Supplement 2, 1992
02
generation is greater in stressed (88%) than in control PMNs (48%)
(Ta-
ble I) . Table I - Superoxide anion production (nmol/10 6 cells/20 min) in control and stressed rat PMNs in absence and presence of 5HT . + 5HT (1x10 -4 M) 53 .2 t 2 .9 35 .5 + 3 .3
Controls Stressed
27 .4 t 3 .1 6 .5 t 1 .1
In the luminol-enhanced CL system the result is higher for stressed than control PMNs (Figure 1) . The effect of 5BT result in an inhibition of the CL emitted by PMNs .
Figure 1 : Time trace of CL emitted from PMNs of stressed and control rats ( •- •s tressed, •--- • stressed + 5HT, o-o controls, o---o controls + 5HT)
3 3 . w ( [tea/ 3as, EOI x s)uno3) io
The results in
02
production and CL emission seemed to be not in agreement,
but it may be hypothesize that enhancement of CL in stressed PMNs might be related to a greater availability of MPO content or to an increased activ i ty of MPO-H2 2 -halide system ; luminol-induced CL is really an indicator of intracellular and extracellular activity of the MPO system of the neutrophil . References 1 . Ader R ., Felten D ., Cohen N . Interactions between the brain and the immu ne system . Ann . Rev . Pharmacol . Toxicol . 1990 ; 30 : 561-602 . 2 . Ader R ., Cohen N ., Felten D . Brain, behavior and immunity . Brain . Behav . Immun . 1987 ; 1 : 1-6 . 3 . Teshina H ., Sogawa H ., Kihara H . in Jankovic B .D . et al . Neuroimmune interactions : Proc . 2nd Int . Workshop on Neuroimmunomodulation . In New York Academy of Sci . New York 1987 : 459 . 4 . Cassone M .C ., Fundar6 A ., Molinengo L . Action of 5-hydroxytryptamine, hi stamine and methergoline on phagocytosis . Pharmacology, 1974 ;11 :199-206 . 5 . Van de Kar L .D . Neuroendocrine pharmacology of serotonergic neurons . Ann . Rev . Pharmacol . Toxicol . 1991 ; 31 : 289-320 .