Biomaterial Database

Effects of ambient and stagnant hypoxia on the mechanical and electrical activity of the canine upper jejunum. 1976

A Meissner, and K L Bowes, and S K Sarna

The effects of ambient and stagnant hypoxia on the mechanical and electrical activity of the upper jejunum were studied in 32 anesthetized dogs. A 50 or 75% reduction in oxygen content of inhaled air produced ambient hypoxia; superior mesenteric artery (SMA) occlusion or thrombin-induced mesenteric thrombosis resulted in stagnant hypoxia. Induction of hypoxia was immediately followed by a transient increase in mechanical activity. A 50% reduction in oxygen content had no other effect. A 75% reduction in oxygen content resulted in a gradual decrease in electrical control activity (ECA) frequency and in the disappearance of electrical response activity (ERA), and in jejunal contractions; however, ECA persisted until cardiac arrest occurred after 30 to 45 minutes of hypoxia. Occlusion of the SMA resulted in a significant decrease in contractile activity but ECA was not affected. Thrombin-induced mesenteric thrombosis produced rapid and irreversible disappearance of both electrical and mechanical activities. Jejunal contractions and ERA are dependent upon an adequate oxygenated blood supply. ECA however, is highly resistant to reduction in oxygen content of perfused blood and continues until perfusion stops.

UI	MeSH Term	Description	Entries
D007583	Jejunum	The middle portion of the SMALL INTESTINE, between DUODENUM and ILEUM. It represents about 2/5 of the remaining portion of the small intestine below duodenum.	Jejunums
D009119	Muscle Contraction	A process leading to shortening and/or development of tension in muscle tissue. Muscle contraction occurs by a sliding filament mechanism whereby actin filaments slide inward among the myosin filaments.	Inotropism,Muscular Contraction,Contraction, Muscle,Contraction, Muscular,Contractions, Muscle,Contractions, Muscular,Inotropisms,Muscle Contractions,Muscular Contractions
D009130	Muscle, Smooth	Unstriated and unstriped muscle, one of the muscles of the internal organs, blood vessels, hair follicles, etc. Contractile elements are elongated, usually spindle-shaped cells with centrally located nuclei. Smooth muscle fibers are bound together into sheets or bundles by reticular fibers and frequently elastic nets are also abundant. (From Stedman, 25th ed)	Muscle, Involuntary,Smooth Muscle,Involuntary Muscle,Involuntary Muscles,Muscles, Involuntary,Muscles, Smooth,Smooth Muscles
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
D004594	Electrophysiology	The study of the generation and behavior of electrical charges in living organisms particularly the nervous system and the effects of electricity on living organisms.
D005769	Gastrointestinal Motility	The motor activity of the GASTROINTESTINAL TRACT.	Intestinal Motility,Gastrointestinal Motilities,Intestinal Motilities,Motilities, Gastrointestinal,Motilities, Intestinal,Motility, Gastrointestinal,Motility, Intestinal
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
D000860	Hypoxia	Sub-optimal OXYGEN levels in the ambient air of living organisms.	Anoxia,Oxygen Deficiency,Anoxemia,Deficiency, Oxygen,Hypoxemia,Deficiencies, Oxygen,Oxygen Deficiencies