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Involvement of substance P in the paroxysmal cough of pertussis
238
Regulatory Peptldes, 46 (1993) 238-240 © 1993 Elsevier SciencePubhshers B V All rights reserved 0167-0115/93/$0600
REGPEP 01421
Involvement of substance P in the paroxysmal cough of pertussis Shigeml Y o s h l h a r a a, N o r i k o K a n n o a, T a m o t s u A n d o a, N o n m a s a F u k u d a a, T o s h l o Abe ~, T o h j u I c h l m u r a a and N o b o r u Y a n a i h a r a b First Department of Ped:atncs, Dokkyo Umverslty School of Medicine, Tochlgt(Japan) and bLaboratory of Bworgamc Chemtstry, Umverslty of Shlzuoka, School of Pharmaceuttcal Science, Shtzuoka (Japan) Key words Pertussls; Pertussls toxin; Cough; Neuropeptlde, Substance P; Respiratory disease; Neutral
endopeptldase
Introduction
In pertussls, characteristic paroxysmal and continuous cough persists for several weeks after eradication of the pathogen. The treatment of this &sease may be facilitated by elucidation of the pathogenic mechanism of these cough attacks On the other hand, substance P (SP) is known to be a neuropeptide that causes coughs [ 1] In this study, we evaluated whether SP is revolved in the cough attacks of pertussis
Materials and Methods
The subjects were chddren admitted to the Department of Pediatrics, Dokkyo Umversity Hospital and were &agnosed as having pertussis. The diagnosis was made according to the WHO criteria, i.e, when attacks of paroxysmal cough continued for 21 days or longer, when pertussls antibody was signifIcantly increased, and when lymphocytosls was obCorrespondence to S Yoshlhara, Ftrst Departmentof Pediatrics, Dokkyo Umverslty Schoolof Medicine, Tochlgl321-02, Japan
served in the peripheral blood. Children with asthma who were examined at the allergy chnlc of our department were regarded as the asthma group, and healthy volunteer chddren were examined as controls with the consent of their parents The ages of the subjects in the pertussls group, asthma group, and control group were equahzed as much as possible Blood was sampled at a fixed time of the day m consideration of within-day changes. Blood collected in Spitz tubes contmmng EDTA-2Na and Trasylol was immediately cooled, centrifuged, and the plasma was frozen for storage. SP was assayed in all samples on the same day with an SP-specific radioimmunoasaay(RIA) using antiserum R400 [2,3] The sensltwlty of the RIA for SP was 1 pg/ml plasma The SP concentration was expressed in pg/ml for plasma. Difference were regarded as significant at P < 0 . 0 5 (Student's t-test)
Results
As shown in Table I, the plasma SP concentration in the pertussls group was 25 + 10 pg/ml dunng the paroxysmal coughing stage, being significantly higher
239 TABLE I 40-
Concentration of substance P m plasma SubJects Pertussls Coughing stage Recovery stage Healthy children Asthma Attack stage Attack-free stage
Substance P (pg/ml)
30-
20-
25 + 10 9 + 2** 10 + 3** 14 + 3* 6 + 3**
** P < 0 01, n = 7 ; m e a n + S D., * P < 0 05, n = 5 , m e a n + S D
than 9 + 2 pg/ml during the recovery stage or 10 + 3 pg/ml in the control group (P<0.01, n = 7 ; mean + S.D.) Also, it was significantly higher than 14+3 pg/ml (P<0.05, n = 5 ; mean+ S.D.) in the asthma group during attacks or 6 + 3 pg/ml ( P < 0 01, n = 7; mean + S.D ) during the attack-free stages. Fig. 1 shows the results of senal measurements of the plasma SP concentration m a 3-month-old girl from early in the coughing stage to the recovery stage The plasma SP concentration decreased with the number of cough attacks from the coughing stage (42 pg/ml on day 15, 37 pg/ml on day 21, 24 pg/ml on day 26, and 24 pg/ml on day 31) to the recovery stage (14 pg/ml on day 37 and 10 pg/ml on day 45).
Discussion
Since the plasma SP concentration was higher in the pertussls group during the coughing stage than during the recovery stage or in the healthy controls, SP is considered to be involved m attacks of paroxysmal cough of pertussis. Also, the plasma SP concentration decreased with the number of coughing attacks in a 3-month-old girl from early coughmg stage to the recovery stage. This also suggests a close involvement of SP in attacks of paroxysmal cough. Furthermore, the plasma SP concentration was higher during cough attacks of pertussis than during
10-
0
io
2'0
3'o
40
s'o (days)
Fig 1 Serial changes m the number of cough attacks ( O ) and the plasma substance P concentration ( 0 ) in a 3-month-old garl from early in the coughing stage to the recovery stage Units plasma substance P concentralaon, pg/ml, number of cough attacks, number/day
attacks of asthma so that SP is considered to play a greater role in pertussis than in other respiratory diseases
In guinea pigs, tachykinins, typically SP, are released from C-fibers, which are sensory nerves of the airway, under direct stimulation by capsaicin inhalation [4], and they are considered to induce coughs by stimulating cough receptors. Moreover, the cough reduced by capsaicln mhalatton is reported to be significantly aggravated by an inhibitor of neutral endopeptidase (NEP), which degrades SP [5]. On the basis of these observations, we speculated on the role of SP in the mechanism of paroxysmal cough attacks of pertussis. In the coughmg stage ofpertussls, bronchial epithelial cells show atypical proliferation, become tall, and are exfoliated by vigorous paroxysmal coughing. This exposes unmyehnated primary sensory nerve terminals of C-fibers, make them more sensitive to stimulation, and increases the release of SP. SP, on the other hand, is considered to degraded by NEP in the airway. Since NEP is present m large amounts in the mrway epithelium, the N E P activity in the airway as considered to be reduced by exfoliatlon of the airway epithehum. Also, cough persists as long as the effect of pertussts toxin remains. From these observations, pertussis toxin is considered to suppress NEP, which IS an SP-degradlng enzyme
240
Acknowledgement T h i s w o r k was s u p p o r t e d by a g r a n t - i n - a i d for the Ministry
of
Education,
Science
and
Culture
(02857131) by the J a p a n e s e G o v e r n m e n t
References 1 Kohroga, H , Graf, P D , Seklzawa, K, Borson, D B and Nadel, J A, Neutral endopepUdase lnhibxtors potentiate substance P-and capsmcm-induced cough in awake guinea pigs, J Chn Invest, 82 (1988) 2063-2068 2 Yanalhara, N , Sakagaml, M , Sato, H_, Yamamoto, K, Hash-
lmoto, T , Yanalhara, C, Ito, Z., Yamaguchl, K and Abe, K , Immunologacal aspects of secretln,substance P and VIP, Gastroenterology, 72 (1977) 803-810 3 Asm, H , Yoshdaara, S, Ichlmura, T , Iguchl, K and Yanaaha.ra, N , Changes m substance P and vasoactlve intestinal polypeptide levels in the respiratory tract of aging guinea pigs, Biomedical Res, 12 (1991) 41-46 4 Sana, A, Marthng, C R, Yan, Z , Norhelm, E T , Gamse, R , and Lundberg, J M, Release of multiple tachykmms from capsalcln-sensltave sensory nerves in the lung by bradyklnm, histamine, &methylphenyl plperazlnmm, and vagal nerve sumulatlon, Am Rev_ Resp Dis , 137 (1988) 1330-1335 5 Borson, D.B, Malfroy, B, Gold, M, Ramachandran, J and Nadel, J A, Tachykmms inhibit enkephahnase actwlty from tracheas and lungs of ferrets, Phys~ologast, 29 (1986) 174
Regulatory Peptldes, 46 (1993) 238-240 © 1993 Elsevier SciencePubhshers B V All rights reserved 0167-0115/93/$0600
REGPEP 01421
Involvement of substance P in the paroxysmal cough of pertussis Shigeml Y o s h l h a r a a, N o r i k o K a n n o a, T a m o t s u A n d o a, N o n m a s a F u k u d a a, T o s h l o Abe ~, T o h j u I c h l m u r a a and N o b o r u Y a n a i h a r a b First Department of Ped:atncs, Dokkyo Umverslty School of Medicine, Tochlgt(Japan) and bLaboratory of Bworgamc Chemtstry, Umverslty of Shlzuoka, School of Pharmaceuttcal Science, Shtzuoka (Japan) Key words Pertussls; Pertussls toxin; Cough; Neuropeptlde, Substance P; Respiratory disease; Neutral
endopeptldase
Introduction
In pertussls, characteristic paroxysmal and continuous cough persists for several weeks after eradication of the pathogen. The treatment of this &sease may be facilitated by elucidation of the pathogenic mechanism of these cough attacks On the other hand, substance P (SP) is known to be a neuropeptide that causes coughs [ 1] In this study, we evaluated whether SP is revolved in the cough attacks of pertussis
Materials and Methods
The subjects were chddren admitted to the Department of Pediatrics, Dokkyo Umversity Hospital and were &agnosed as having pertussis. The diagnosis was made according to the WHO criteria, i.e, when attacks of paroxysmal cough continued for 21 days or longer, when pertussls antibody was signifIcantly increased, and when lymphocytosls was obCorrespondence to S Yoshlhara, Ftrst Departmentof Pediatrics, Dokkyo Umverslty Schoolof Medicine, Tochlgl321-02, Japan
served in the peripheral blood. Children with asthma who were examined at the allergy chnlc of our department were regarded as the asthma group, and healthy volunteer chddren were examined as controls with the consent of their parents The ages of the subjects in the pertussls group, asthma group, and control group were equahzed as much as possible Blood was sampled at a fixed time of the day m consideration of within-day changes. Blood collected in Spitz tubes contmmng EDTA-2Na and Trasylol was immediately cooled, centrifuged, and the plasma was frozen for storage. SP was assayed in all samples on the same day with an SP-specific radioimmunoasaay(RIA) using antiserum R400 [2,3] The sensltwlty of the RIA for SP was 1 pg/ml plasma The SP concentration was expressed in pg/ml for plasma. Difference were regarded as significant at P < 0 . 0 5 (Student's t-test)
Results
As shown in Table I, the plasma SP concentration in the pertussls group was 25 + 10 pg/ml dunng the paroxysmal coughing stage, being significantly higher
239 TABLE I 40-
Concentration of substance P m plasma SubJects Pertussls Coughing stage Recovery stage Healthy children Asthma Attack stage Attack-free stage
Substance P (pg/ml)
30-
20-
25 + 10 9 + 2** 10 + 3** 14 + 3* 6 + 3**
** P < 0 01, n = 7 ; m e a n + S D., * P < 0 05, n = 5 , m e a n + S D
than 9 + 2 pg/ml during the recovery stage or 10 + 3 pg/ml in the control group (P<0.01, n = 7 ; mean + S.D.) Also, it was significantly higher than 14+3 pg/ml (P<0.05, n = 5 ; mean+ S.D.) in the asthma group during attacks or 6 + 3 pg/ml ( P < 0 01, n = 7; mean + S.D ) during the attack-free stages. Fig. 1 shows the results of senal measurements of the plasma SP concentration m a 3-month-old girl from early in the coughing stage to the recovery stage The plasma SP concentration decreased with the number of cough attacks from the coughing stage (42 pg/ml on day 15, 37 pg/ml on day 21, 24 pg/ml on day 26, and 24 pg/ml on day 31) to the recovery stage (14 pg/ml on day 37 and 10 pg/ml on day 45).
Discussion
Since the plasma SP concentration was higher in the pertussls group during the coughing stage than during the recovery stage or in the healthy controls, SP is considered to be involved m attacks of paroxysmal cough of pertussis. Also, the plasma SP concentration decreased with the number of coughing attacks in a 3-month-old girl from early coughmg stage to the recovery stage. This also suggests a close involvement of SP in attacks of paroxysmal cough. Furthermore, the plasma SP concentration was higher during cough attacks of pertussis than during
10-
0
io
2'0
3'o
40
s'o (days)
Fig 1 Serial changes m the number of cough attacks ( O ) and the plasma substance P concentration ( 0 ) in a 3-month-old garl from early in the coughing stage to the recovery stage Units plasma substance P concentralaon, pg/ml, number of cough attacks, number/day
attacks of asthma so that SP is considered to play a greater role in pertussis than in other respiratory diseases
In guinea pigs, tachykinins, typically SP, are released from C-fibers, which are sensory nerves of the airway, under direct stimulation by capsaicin inhalation [4], and they are considered to induce coughs by stimulating cough receptors. Moreover, the cough reduced by capsaicln mhalatton is reported to be significantly aggravated by an inhibitor of neutral endopeptidase (NEP), which degrades SP [5]. On the basis of these observations, we speculated on the role of SP in the mechanism of paroxysmal cough attacks of pertussis. In the coughmg stage ofpertussls, bronchial epithelial cells show atypical proliferation, become tall, and are exfoliated by vigorous paroxysmal coughing. This exposes unmyehnated primary sensory nerve terminals of C-fibers, make them more sensitive to stimulation, and increases the release of SP. SP, on the other hand, is considered to degraded by NEP in the airway. Since NEP is present m large amounts in the mrway epithelium, the N E P activity in the airway as considered to be reduced by exfoliatlon of the airway epithehum. Also, cough persists as long as the effect of pertussts toxin remains. From these observations, pertussis toxin is considered to suppress NEP, which IS an SP-degradlng enzyme
240
Acknowledgement T h i s w o r k was s u p p o r t e d by a g r a n t - i n - a i d for the Ministry
of
Education,
Science
and
Culture
(02857131) by the J a p a n e s e G o v e r n m e n t
References 1 Kohroga, H , Graf, P D , Seklzawa, K, Borson, D B and Nadel, J A, Neutral endopepUdase lnhibxtors potentiate substance P-and capsmcm-induced cough in awake guinea pigs, J Chn Invest, 82 (1988) 2063-2068 2 Yanalhara, N , Sakagaml, M , Sato, H_, Yamamoto, K, Hash-
lmoto, T , Yanalhara, C, Ito, Z., Yamaguchl, K and Abe, K , Immunologacal aspects of secretln,substance P and VIP, Gastroenterology, 72 (1977) 803-810 3 Asm, H , Yoshdaara, S, Ichlmura, T , Iguchl, K and Yanaaha.ra, N , Changes m substance P and vasoactlve intestinal polypeptide levels in the respiratory tract of aging guinea pigs, Biomedical Res, 12 (1991) 41-46 4 Sana, A, Marthng, C R, Yan, Z , Norhelm, E T , Gamse, R , and Lundberg, J M, Release of multiple tachykmms from capsalcln-sensltave sensory nerves in the lung by bradyklnm, histamine, &methylphenyl plperazlnmm, and vagal nerve sumulatlon, Am Rev_ Resp Dis , 137 (1988) 1330-1335 5 Borson, D.B, Malfroy, B, Gold, M, Ramachandran, J and Nadel, J A, Tachykmms inhibit enkephahnase actwlty from tracheas and lungs of ferrets, Phys~ologast, 29 (1986) 174