Dimethylthiourea reverses sepsis-induced pulmonary hypertension in piglets.
Dimethylthiourea (DMTU), a putative hydroxyl radical scavenger, attenuates thromboxane generation and pulmonary hypertension in the piglet model of group B streptococcal (GBS) sepsis. This study tested the hypothesis that DMTU reverses ongoing GBS-induced pulmonary hypertension coincident with decreased thromboxane production. Piglets (n = 15) received a 60 min infusion of GBS (10(-8) cfu/kg/min). Mean pulmonary artery pressure (Ppa), arterial blood gases (ABGs), and thromboxane B2 (TXB) levels were measured at 10 min intervals throughout the study. GBS infusion resulted in a marked increase in pulmonary artery pressure (mean delta Ppa = 31 mm Hg) and a significant decline in PaO2 (mean = -80 torr) within 10 min of beginning the infusion. pH decreased from a mean of 7.47 to 7.37. DMTU, 750 mg/kg, or normal saline vehicle was infused over 10-15 min beginning 10 min after initiating GBS. Ppa decreased significantly within 10 min of DMTU infusion. Piglets receiving vehicle had a slow decline in Ppa. Piglets receiving DMTU also had an improvement in PaO2 and showed no further drop in pH. Piglets receiving vehicle had no improvement in PaO2 and demonstrated a continued decline in pH. TXB levels did not differ between the groups at any time interval. We conclude that DMTU can partially reverse GBS-induced pulmonary hypertension, but may function through mechanisms independent of thromboxane generation.
Shook
L A
LA
University of Kentucky, A.B. Chandler Medical Center, College of Medicine, Department of Pediatrics, Lexington.
Pauly
T H
TH
Horstman
S J
SJ
Marple
S L
SL
Gillespie
M N
MN
D000818:Animals; D000831:Animals, Newborn; D001794:Blood Pressure / Q000187:drug effects; D004195:Disease Models, Animal; D006976:Hypertension, Pulmonary / Q000188:drug therapy* / Q000209:etiology; D010100:Oxygen / Q000097:blood; D010313:Partial Pressure; D011652:Pulmonary Circulation; D018805:Sepsis / Q000503:physiopathology*; D013290:Streptococcal Infections / Q000503:physiopathology*; D013552:Swine; D013890:Thiourea / Q000031:analogs & derivatives* / Q000627:therapeutic use; D013929:Thromboxane B2 / Q000097:blood
D013929:Thromboxane B2; C038983:1,3-dimethylthiourea; D013890:Thiourea; D010100:Oxygen