Biomaterial Database

Pulmonary vasoregulation by arginine vasopressin in conscious, halothane-anesthetized, and pentobarbital-anesthetized dogs with increased vasomotor tone. 1994

G A Trempy, and D P Nyhan, and P A Murray

Department of Anesthesiology and Critical Care Medicine, Johns Hopkins Medical Institutions, Baltimore, Maryland.

BACKGROUND Arginine vasopressin (AVP) is an important "stress" hormone that is known to play a key role in cardiovascular homeostasis of the systemic circulation. In contrast, the effects of AVP on the pulmonary circulation have not been extensively investigated, and the extent to which general anesthesia alters the pulmonary vascular response to AVP is entirely unknown. Our first objective was to assess the effects of AVP on the pulmonary vascular pressure-flow relation in chronically instrumented conscious dogs in the setting of an acute elevation in pulmonary vasomotor tone. Our second objective was to investigate the effects of halothane and pentobarbital anesthesia on the pulmonary vascular response to AVP after inducing the same degree of pulmonary preconstriction achieved in the conscious state. METHODS Conditioned, mongrel dogs were chronically instrumented to measure the left pulmonary vascular pressure-flow (LPQ) relation. LPQ plots were generated by continuously measuring the pulmonary vascular pressure gradient (pulmonary arterial pressure minus left atrial pressure) and left pulmonary blood flow during gradual (approximately 1 min) inflation of a hydraulic occluder around the right pulmonary artery, which directed total pulmonary blood flow through the left pulmonary circulation. LPQ plots were generated in conscious (n = 10), halothane-anesthetized (n = 9) and pentobarbital-anesthetized (n = 7) dogs. In each condition, LPQ plots were measured at baseline, during the intravenous administration of the thromboxane analog U46619 and during the cumulative administration of AVP (2-19 ng.kg-1.min-1, intravenous) in the presence of U46619 preconstriction. RESULTS U46619 caused acute pulmonary vasoconstriction (P < 0.01) in conscious dogs. In this setting of U46619 preconstriction, AVP caused pulmonary vasodilation (P < 0.05) in the conscious state. In contrast, despite identical levels of U46619 preconstriction, the pulmonary vasodilator response to AVP was either reversed to vasoconstriction (P < 0.05) or abolished during halothane and pentobarbital anesthesia. CONCLUSIONS These results indicate that AVP exerts a significant pulmonary vasodilator response in the setting of acute pulmonary vasoconstriction in conscious dogs. However, the pulmonary vascular response to this stress hormone is markedly altered during halothane and pentobarbital anesthesia.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D010424	Pentobarbital	A short-acting barbiturate that is effective as a sedative and hypnotic (but not as an anti-anxiety) agent and is usually given orally. It is prescribed more frequently for sleep induction than for sedation but, like similar agents, may lose its effectiveness by the second week of continued administration. (From AMA Drug Evaluations Annual, 1994, p236)	Mebubarbital,Mebumal,Diabutal,Etaminal,Ethaminal,Nembutal,Pentobarbital Sodium,Pentobarbital, Monosodium Salt,Pentobarbitone,Sagatal,Monosodium Salt Pentobarbital
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
D003243	Consciousness	Sense of awareness of self and of the environment.	Consciousnesses
D004285	Dogs	The domestic dog, Canis familiaris, comprising about 400 breeds, of the carnivore family CANIDAE. They are worldwide in distribution and live in association with people. (Walker's Mammals of the World, 5th ed, p1065)	Canis familiaris,Dog
D006221	Halothane	A nonflammable, halogenated, hydrocarbon anesthetic that provides relatively rapid induction with little or no excitement. Analgesia may not be adequate. NITROUS OXIDE is often given concomitantly. Because halothane may not produce sufficient muscle relaxation, supplemental neuromuscular blocking agents may be required. (From AMA Drug Evaluations Annual, 1994, p178)	1,1,1-Trifluoro-2-Chloro-2-Bromoethane,Fluothane,Ftorotan,Narcotan
D000758	Anesthesia	A state characterized by loss of feeling or sensation. This depression of nerve function is usually the result of pharmacologic action and is induced to allow performance of surgery or other painful procedures.
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
D001127	Arginine Vasopressin	The predominant form of mammalian antidiuretic hormone. It is a nonapeptide containing an ARGININE at residue 8 and two disulfide-linked cysteines at residues of 1 and 6. Arg-vasopressin is used to treat DIABETES INSIPIDUS or to improve vasomotor tone and BLOOD PRESSURE.	Argipressin,Vasopressin, Arginine,Arg-Vasopressin,Argipressin Tannate,Arg Vasopressin