Biomaterial Database

Hypotensive effects of lesions of the rostral ventrolateral medulla in rats are anesthetic-dependent. 1988

K L Cochrane, and R A Buchholz, and J W Hubbard, and T K Keeton, and M A Nathan

Department of Pharmacology, University of Texas Health Science Center, San Antonio 78284-7764.

These studies were designed to determine if the hypotensive effects of bilateral electrolytic lesions of the rostral ventrolateral medulla are dependent on the type of anesthetic agent used. The lesions caused an immediate fall in mean arterial pressure (MAP) in rats anesthetized with urethane, alpha-chloralose or sodium pentobarbital. At 30 min after placement of the lesions, severe hypotension (MAP = 54 +/- 5 mm Hg) persisted in the rats anesthetized with urethane. However, 30 min after placement of the lesions, the MAP of rats anesthetized with alpha-chloralose or sodium pentobarbital was 87 +/- 9 mm Hg and 99 +/- 10 mm Hg, respectively. Subsequent transection of the cervical spinal cord produced a much greater decrease in MAP in rats anesthetized with alpha-chloralose and sodium pentobarbital as compared to rats anesthetized with urethane. Heart rate was significantly lower after placement of the lesions in all 3 groups. We conclude that the magnitude of the hypotensive effect caused by placement of lesions in the rostral ventrolateral medulla is anesthetic-dependent and that the rostral ventrolateral medulla is not the only area of the central nervous system capable of maintaining vasomotor tone.

UI	MeSH Term	Description	Entries
D007022	Hypotension	Abnormally low BLOOD PRESSURE that can result in inadequate blood flow to the brain and other vital organs. Common symptom is DIZZINESS but greater negative impacts on the body occur when there is prolonged depravation of oxygen and nutrients.	Blood Pressure, Low,Hypotension, Vascular,Low Blood Pressure,Vascular Hypotension
D008297	Male		Males
D008526	Medulla Oblongata	The lower portion of the BRAIN STEM. It is inferior to the PONS and anterior to the CEREBELLUM. Medulla oblongata serves as a relay station between the brain and the spinal cord, and contains centers for regulating respiratory, vasomotor, cardiac, and reflex activities.	Accessory Cuneate Nucleus,Ambiguous Nucleus,Arcuate Nucleus of the Medulla,Arcuate Nucleus-1,External Cuneate Nucleus,Lateral Cuneate Nucleus,Nucleus Ambiguus,Ambiguus, Nucleus,Arcuate Nucleus 1,Arcuate Nucleus-1s,Cuneate Nucleus, Accessory,Cuneate Nucleus, External,Cuneate Nucleus, Lateral,Medulla Oblongatas,Nucleus, Accessory Cuneate,Nucleus, Ambiguous,Nucleus, External Cuneate,Nucleus, Lateral Cuneate
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
D001794	Blood Pressure	PRESSURE of the BLOOD on the ARTERIES and other BLOOD VESSELS.	Systolic Pressure,Diastolic Pressure,Pulse Pressure,Pressure, Blood,Pressure, Diastolic,Pressure, Pulse,Pressure, Systolic,Pressures, Systolic
D002698	Chloralose	A derivative of CHLORAL HYDRATE that was used as a sedative but has been replaced by safer and more effective drugs. Its most common use is as a general anesthetic in animal experiments.	Anhydroglucochloral,Glucochloral,Glucochloralose,alpha-Chloralose,beta-Chloralose,alpha Chloralose,beta Chloralose
D006339	Heart Rate	The number of times the HEART VENTRICLES contract per unit of time, usually per minute.	Cardiac Rate,Chronotropism, Cardiac,Heart Rate Control,Heartbeat,Pulse Rate,Cardiac Chronotropy,Cardiac Chronotropism,Cardiac Rates,Chronotropy, Cardiac,Control, Heart Rate,Heart Rates,Heartbeats,Pulse Rates,Rate Control, Heart,Rate, Cardiac,Rate, Heart,Rate, Pulse
D000777	Anesthetics	Agents capable of inducing a total or partial loss of sensation, especially tactile sensation and pain. They may act to induce general ANESTHESIA, in which an unconscious state is achieved, or may act locally to induce numbness or lack of sensation at a targeted site.	Anesthetic,Anesthetic Agents,Anesthetic Drugs,Anesthetic Effect,Anesthetic Effects,Agents, Anesthetic,Drugs, Anesthetic,Effect, Anesthetic,Effects, Anesthetic
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
D014294	Trimethaphan	A nicotinic antagonist that has been used as a ganglionic blocker in hypertension, as an adjunct to anesthesia, and to induce hypotension during surgery.	Thimethaphan,Trimetaphan