Biomaterial Database

Effects of respiratory alkalosis on thromboxane-induced pulmonary hypertension in piglets. 1988

G J Redding, and R L Gibson, and C B Davis, and W E Truog

Department of Pediatrics, University of Washington School of Medicine, Seattle 98195.

Acute hypoxic pulmonary vasoconstriction is attenuated by respiratory alkalosis. It is unknown if alkalosis similarly reduces pulmonary vasoconstriction produced by thromboxane A2. Respiratory alkalosis does not always attenuate persistent pulmonary hypertension in newborns, some of whom have elevated serum thromboxane B2 levels. We hypothesized that alkalosis attenuates thromboxane-induced pulmonary vasoconstriction less than it does hypoxic pulmonary vasoconstriction in infants. Hemodynamic responses to respiratory alkalosis during pulmonary vasoconstriction produced in random order by breathing 12% inspired oxygen and by infusing 0.1 micrograms/kg/min of the thromboxane-mimetic U46,619 were compared in eight 2-wk-old piglets. Hypoxia increased mean pulmonary artery pressure from 12 +/- 3 to 29 +/- 2 mm Hg and pulmonary vascular resistance (PVR) from 11 +/- 4 to 25 +/- 8 mmHg/L/min; U46,619 increased pulmonary artery pressure from 16 +/- 5 to 37 +/- 6 mm Hg and PVR from 14 +/- 5 to 51 +/- 17 mm Hg/liter/min. U46,619 also decreased cardiac output accounting in part for the greater increase in PVR compared to hypoxia-induced vasoconstriction. Respiratory alkalosis decreased PVR to 14 +/- 6 mm Hg/liter/min during exposure to hypoxia and to 28 +/- 9 mm Hg/liter/min during infusion of U46,619. In six additional piglets with U46,619-induced pulmonary vasoconstriction, the effects of lung stretch and hypocapnic alkalosis were separated by doubling tidal volume and then adding inspired CO2 to return PaCO2 to prehyperventilation levels. Respiratory alkalosis decreased PVR from 52 +/- 36 to 35 +/- 21 mm Hg/liter/min. Despite the increased tidal volume, PVR increased to 53 +/- 35 Hg/liter/min when PaCO2 returned to 44 +/- 5 mm Hg.(ABSTRACT TRUNCATED AT 250 WORDS)

UI	MeSH Term	Description	Entries
D006976	Hypertension, Pulmonary	Increased VASCULAR RESISTANCE in the PULMONARY CIRCULATION, usually secondary to HEART DISEASES or LUNG DISEASES.	Pulmonary Hypertension
D011450	Prostaglandin Endoperoxides, Synthetic	Synthetic compounds that are analogs of the naturally occurring prostaglandin endoperoxides and that mimic their pharmacologic and physiologic activities. They are usually more stable than the naturally occurring compounds.	Prostaglandin Endoperoxide Analogs,Prostaglandin Endoperoxide Analogues,Synthetic Prostaglandin Endoperoxides,Analogues, Prostaglandin Endoperoxide,Endoperoxide Analogues, Prostaglandin,Endoperoxides, Synthetic Prostaglandin
D011652	Pulmonary Circulation	The circulation of the BLOOD through the LUNGS.	Pulmonary Blood Flow,Respiratory Circulation,Circulation, Pulmonary,Circulation, Respiratory,Blood Flow, Pulmonary,Flow, Pulmonary Blood,Pulmonary Blood Flows
D011659	Pulmonary Gas Exchange	The exchange of OXYGEN and CARBON DIOXIDE between alveolar air and pulmonary capillary blood that occurs across the BLOOD-AIR BARRIER.	Exchange, Pulmonary Gas,Gas Exchange, Pulmonary
D006439	Hemodynamics	The movement and the forces involved in the movement of the blood through the CARDIOVASCULAR SYSTEM.	Hemodynamic
D000472	Alkalosis, Respiratory	A state due to excess loss of carbon dioxide from the body. (Dorland, 27th ed)	Respiratory Alkalosis,Alkaloses, Respiratory,Respiratory Alkaloses
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013552	Swine	Any of various animals that constitute the family Suidae and comprise stout-bodied, short-legged omnivorous mammals with thick skin, usually covered with coarse bristles, a rather long mobile snout, and small tail. Included are the genera Babyrousa, Phacochoerus (wart hogs), and Sus, the latter containing the domestic pig (see SUS SCROFA).	Phacochoerus,Pigs,Suidae,Warthogs,Wart Hogs,Hog, Wart,Hogs, Wart,Wart Hog
D013928	Thromboxane A2	An unstable intermediate between the prostaglandin endoperoxides and thromboxane B2. The compound has a bicyclic oxaneoxetane structure. It is a potent inducer of platelet aggregation and causes vasoconstriction. It is the principal component of rabbit aorta contracting substance (RCS).	Rabbit Aorta Contracting Substance,A2, Thromboxane
D013990	Tidal Volume	The volume of air inspired or expired during each normal, quiet respiratory cycle. Common abbreviations are TV or V with subscript T.	Tidal Volumes,Volume, Tidal,Volumes, Tidal