Influence of controlled hypotension by adenosine triphosphate or nitroglycerin on the neuromuscular blocking effect of atracurium in dogs.
The neuromuscular blocking effect of atracurium under the influence of controlled hypotension by adenosine triphosphate (ATP) or nitroglycerin (NTG) was studied in mongrel dogs under halothane anesthesia. Under hypotensive state (60 +/- 5 mmHg) elicited by ATP (0.5 mg/kg/min) or NTG (1 microgram/kg/min), the neuromuscular blockade produced by atracurium (30 micrograms/kg, i.v.) was significantly potentiated and prolonged. The maximal depression of twitch contraction of the gastrocnemius-soleus muscle increased from 10 +/- 3% to 36 +/- 10% (ATP group) and 56.0 +/- 2.4% (NTG group), while the duration of neuromuscular blockade was prolonged from 663 +/- 96 s to 1060 +/- 277 s (ATP group), and 1375 +/- 441 s (NTG group). The potentiation and prolongation of neuromuscular blockade by atracurium was still apparent upon reversal of the hypotensive effect of ATP, but not of NTG, by dopamine infusion. We suggest that ATP may prolong and augment the effect of atracurium by reducing the presynaptic release of acetylcholine at the neuromuscular junction.
Chan
K H
KH
Department of Anesthesiology, Veterans General Hospital, Taipei, Taiwan, Republic of China.
Mui
W C
WC
Yang
M W
MW
Lee
T Y
TY
D000255:Adenosine Triphosphate / Q000494:pharmacology*; D000818:Animals; D001279:Atracurium / Q000494:pharmacology*; D004285:Dogs; D004357:Drug Synergism; D005260:Female; D006614:Hindlimb; D007023:Hypotension, Controlled; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009466:Neuromuscular Blocking Agents / Q000494:pharmacology*; D005996:Nitroglycerin / Q000494:pharmacology*
D009466:Neuromuscular Blocking Agents; D001279:Atracurium; D000255:Adenosine Triphosphate; D005996:Nitroglycerin