• Something wrong with this record ?

Myogenic nature of insect heartbeat and intestinal peristalsis, revealed by neuromuscular paralysis caused by the sting of a braconid wasp

K. Sláma, J. Lukáš

. 2011 ; 57 (2) : 251-259.

Language English Country England, Great Britain

Document type Journal Article, Research Support, Non-U.S. Gov't

Persistent link   https://www.medvik.cz/link/bmc12027268

Larvae of the greater waxmoth (Galleria mellonella) become paralysed by the venom of the braconid wasp (Habrobracon hebetor) a few minutes after intoxication. The profound neuromuscular paralysis, which may last for several weeks, includes all somatic muscles that are innervated through neuromuscular transmission. The peristaltic contractions of the heart and intestine, which are regulated by the depolarisation potentials of the myocardium or intestinal epithelial muscles, remain unaffected and fully functional. Heartbeat patterns and intestinal pulsations were monitored in the motionless, paralysed larvae by means of advanced electrocardiographic recording methods (contact thermography, pulse-light optocardiography). The records revealed more or less constant cardiac pulsations characterised by 20-25 systolic contractions per minute. The contractions were peristaltically propagated in the forward (anterograde) direction, with a more or less constant speed of 10mm per second (23-25°C). Additional electrocardiographic investigations on larvae immobilised by decapitation revealed the autonomic (brain independent) nature of heartbeat regulation. Sectioning performed in the middle of the heart (4th abdominal segment) seriously impaired the pacemaker rhythmicity and slowed down the rate of heartbeat in the anterior sections. By contrast, the functions of the posterior compartments of the disconnected heart remained unaffected. These results confirmed our previous conclusions about the existence of an autonomic, myogenic, pacemaker nodus in the terminal part of an insect heart. They show an analogy to the similar myogenic, sinoatrial or atrioventricular nodi regulating rhythmicity of the human heart. Peristaltic contractions of the intestine also represent a purely myogenic system, which is fully functional in larvae with complete neuromuscular paralysis. Unlike the constant anterograde direction of the heartbeat, intestinal peristaltic waves periodically reversed anterograde and retrograde directions. A possibility that the functional similarity between insect and human hearts may open new avenues in the field of comparative cardiology has been discussed.

References provided by Crossref.org

000      
00000naa a2200000 a 4500
001      
bmc12027268
003      
CZ-PrNML
005      
20200929094746.0
007      
ta
008      
120816s2011 enk f 000 0#eng||
009      
AR
024    7_
$a 10.1016/j.jinsphys.2010.11.004 $2 doi
035    __
$a (PubMed)21093450
040    __
$a ABA008 $b cze $d ABA008 $e AACR2
041    0_
$a eng
044    __
$a enk
100    1_
$a Sláma, Karel, $d 1934- $u Biological Center of Czech Academy of Sciences, Institute of Entomology, Drnovská 507, Prague, Czech Republic. slama@entu.cas.cz $7 jk01111779
245    10
$a Myogenic nature of insect heartbeat and intestinal peristalsis, revealed by neuromuscular paralysis caused by the sting of a braconid wasp / $c K. Sláma, J. Lukáš
520    9_
$a Larvae of the greater waxmoth (Galleria mellonella) become paralysed by the venom of the braconid wasp (Habrobracon hebetor) a few minutes after intoxication. The profound neuromuscular paralysis, which may last for several weeks, includes all somatic muscles that are innervated through neuromuscular transmission. The peristaltic contractions of the heart and intestine, which are regulated by the depolarisation potentials of the myocardium or intestinal epithelial muscles, remain unaffected and fully functional. Heartbeat patterns and intestinal pulsations were monitored in the motionless, paralysed larvae by means of advanced electrocardiographic recording methods (contact thermography, pulse-light optocardiography). The records revealed more or less constant cardiac pulsations characterised by 20-25 systolic contractions per minute. The contractions were peristaltically propagated in the forward (anterograde) direction, with a more or less constant speed of 10mm per second (23-25°C). Additional electrocardiographic investigations on larvae immobilised by decapitation revealed the autonomic (brain independent) nature of heartbeat regulation. Sectioning performed in the middle of the heart (4th abdominal segment) seriously impaired the pacemaker rhythmicity and slowed down the rate of heartbeat in the anterior sections. By contrast, the functions of the posterior compartments of the disconnected heart remained unaffected. These results confirmed our previous conclusions about the existence of an autonomic, myogenic, pacemaker nodus in the terminal part of an insect heart. They show an analogy to the similar myogenic, sinoatrial or atrioventricular nodi regulating rhythmicity of the human heart. Peristaltic contractions of the intestine also represent a purely myogenic system, which is fully functional in larvae with complete neuromuscular paralysis. Unlike the constant anterograde direction of the heartbeat, intestinal peristaltic waves periodically reversed anterograde and retrograde directions. A possibility that the functional similarity between insect and human hearts may open new avenues in the field of comparative cardiology has been discussed.
650    _2
$a zvířata $7 D000818
650    _2
$a biologické hodiny $x účinky léků $7 D001683
650    _2
$a elektrokardiografie $x metody $7 D004562
650    _2
$a ženské pohlaví $7 D005260
650    _2
$a srdeční frekvence $7 D006339
650    _2
$a kousnutí a bodnutí hmyzem $x patofyziologie $7 D007299
650    _2
$a střeva $x fyziologie $7 D007422
650    _2
$a můry $x účinky léků $x fyziologie $7 D009036
650    _2
$a svaly $x patofyziologie $7 D009132
650    _2
$a peristaltika $x účinky léků $7 D010528
650    _2
$a nervový přenos $x účinky léků $7 D009435
650    _2
$a vosí jedy $x farmakologie $7 D014862
650    _2
$a sršňovití $7 D014863
655    _2
$a časopisecké články $7 D016428
655    _2
$a práce podpořená grantem $7 D013485
700    1_
$a Lukáš, Jan, $d 1972- $u Research Institute of Crop Production, Drnovská 507, 16100 Praha 6, Czech Republic $7 mzk2005306807
773    0_
$w MED00006287 $t Journal of insect physiology $x 1879-1611 $g Roč. 57, č. 2 (2011), s. 251-259
856    41
$u https://pubmed.ncbi.nlm.nih.gov/21093450 $y Pubmed
910    __
$a ABA008 $b sig $c sign $y m $z 0
990    __
$a 20120816 $b ABA008
991    __
$a 20200929094742 $b ABA008
999    __
$a ok $b bmc $g 949310 $s 784614
BAS    __
$a 3
BAS    __
$a PreBMC
BMC    __
$a 2011 $b 57 $c 2 $d 251-259 $i 1879-1611 $m Journal of insect physiology $n J Insect Physiol $x MED00006287
LZP    __
$b NLK112 $a Pubmed-20120816/11/02

Find record

Citation metrics

Archiving options