Lung compliance, plasma electrolyte levels and acid-base balance are affected by scorpion envenomation in anesthetized rats under mechanical ventilation.
To determine the effects of Tityus serrulatus scorpion toxin on lung compliance and resistance, ionic equilibrium and acid-base balance over time in anesthetized and mechanically ventilated rats, we measured air flow, tracheal and esophageal pressure. Lung volume was obtained by electronic integration of airflow signal. Arterial blood samples were collected through a catheter at baseline (before) and 5, 15, 30 and 60 min after scorpion toxin injection for arterial blood gases, bicarbonate, and alkali reserve levels as well as for, sodium, potassium, magnesium, glucose, lactate, hematocrit, and osmolality analysis. Injection of the gamma fraction of the T. serrulatus scorpion venom in rats under mechanical ventilatory support leads to a continuous decrease in lung compliance secondary to pulmonary edema, but no change in airway resistance. The changes in arterial blood gases characterizing metabolic acidosis were accompanied by an increase in arterial lactate and glucose values, suggesting a scorpion toxin-induced lactic acidosis, in association with poor tissue perfusion (hypotension and low cardiac output). Moreover, scorpion toxin injection resulted in hyperosmolality, hyperkalemia, hypermagnesemia and an increase in hematocrit. The experiments have shown a clinically relevant animal model to study severe scorpion envenoming and may help to better understand the scorpion envenoming syndrome.
Andrade
Marcus V
MV
Department of Internal Medicine, School of Medicine, Universidade Federal de Minas Gerais (UFMG), 30130-100 Belo Horizonte, MG, Brazil. andradem@medicina.ufmg.br
Caramez
Maria Paula R
MP
Abreu
Elnara Marcia N N
EM
Dolnikoff
Marisa
M
Omar
Erick D
ED
Velasco
Irineu T
IT
Cunha-Melo
José R
JR
D000136:Acid-Base Equilibrium / Q000187:drug effects*; D000403:Airway Resistance / Q000187:drug effects; D000468:Alkalies / Q000097:blood; D000818:Animals; D001639:Bicarbonates / Q000097:blood; D001786:Blood Glucose / Q000187:drug effects; D001794:Blood Pressure / Q000187:drug effects; D002245:Carbon Dioxide / Q000097:blood; D002302:Cardiac Output / Q000187:drug effects; D004573:Electrolytes / Q000097:blood*; D006400:Hematocrit; D006863:Hydrogen-Ion Concentration; D007773:Lactates / Q000097:blood; D008170:Lung Compliance / Q000187:drug effects*; D051381:Rats; D012604:Scorpion Venoms / Q000633:toxicity*; D012605:Scorpions; D013997:Time Factors; D014655:Vascular Resistance / Q000187:drug effects
D000468:Alkalies; D001639:Bicarbonates; D001786:Blood Glucose; D004573:Electrolytes; D007773:Lactates; D012604:Scorpion Venoms; D002245:Carbon Dioxide