HOMEPRODUCTSCOMPANYCONTACTFAQResearchDictionaryPharmaSign Up FREE or Login

Roles of platelet-activating factor and thromboxane in group B Streptococcus-induced pulmonary hypertension in piglets.

Abstract
Platelet-activating factor causes pulmonary hypertension, shock, hypoxemia, neutropenia, and increased pulmonary vascular permeability; some of its effects are due to thromboxane A2 release. Evidence for a possible role of these mediators in the genesis of group B Streptococcus (GBS)-induced pulmonary hypertension was sought using specific receptor antagonists for PAF and thromboxane A2 (TxA2) in anesthetized, ventilated piglets (less than or equal to 12 d of age; n = 22). Infusion of 1 X 10(8) GBS/kg/min for one hour resulted in a sustained and significant increase in pulmonary artery pressure (PPA) from 17 +/- 1 to 35 +/- 3 torr. Pretreatment with the TxA2 antagonist SQ 29548 (0.75 mg/kg intravenous), completely inhibited the effect of GBS on PPA. Pretreatment with either platelet-activating factor antagonists SRI 63072 (3 mg/kg intravenous) or SRI 63441 (1 mg/kg) did not affect the pulmonary hypertension due to GBS infusion. GBS-induced pulmonary hypertension could be reversed by SQ 29548; SRI 63072 did not affect PPA when administered to pigs with GBS-induced elevation in PPA. Inasmuch as prevention and reversal of GBS-induced pulmonary hypertension are accomplished with the TxA2 antagonist but not with PAF antagonists, these data suggest that TxA2, rather than PAF, is responsible for the early pulmonary hypertension in this model of neonatal GBS sepsis. Therefore, TxA2 antagonists may be clinically useful in treating pulmonary hypertension related to GBS sepsis.
AuthorsJ M Pinheiro, B R Pitt, C N Gillis
JournalPediatric research (Pediatr Res) Vol. 26 Issue 5 Pg. 420-4 (Nov 1989) ISSN: 0031-3998 [Print] United States
PMID2682499 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.)
Chemical References
  • Prostaglandin Endoperoxides, Synthetic
  • Thromboxane A2
  • Epidermal Growth Factor
Topics
  • Animals
  • Animals, Newborn
  • Blood Pressure (drug effects)
  • Epidermal Growth Factor (antagonists & inhibitors, pharmacology, physiology)
  • Hypertension, Pulmonary (etiology, physiopathology)
  • Prostaglandin Endoperoxides, Synthetic (pharmacology)
  • Pulmonary Artery (physiopathology)
  • Streptococcal Infections (complications)
  • Streptococcus agalactiae
  • Swine
  • Thromboxane A2 (antagonists & inhibitors, physiology)

Join CureHunter, for free Research Interface BASIC access!

Take advantage of free CureHunter research engine access to explore the best drug and treatment options for any disease. Find out why thousands of doctors, pharma researchers and patient activists around the world use CureHunter every day.
Realize the full power of the drug-disease research graph!


Choose Username:
Email:
Password:
Verify Password:
Enter Code Shown: