Effect of arterial pulse pressure and hypoxia on myogenic responses in the gut. 1978

A P Shepherd

In intestine, raising venous pressure (PV) elicits a precapillary vasconstriction that has been ascribed to a myogenic mechanism through which passive stretch elicits active contraction of vascular smooth muscle. A previous report from this laboratory indicated that myogenic responses in the gut were largely dependent on control conditions. The purpose of the present study was to determine whether control blood flow rates or the arterial pulse pressure affects the magnitude of myogenic responses. In isolated perfused canine small bowel arterial hypoxia was used to increase blood flow. Myogenic responses to elevated PV were not significantly different in the normoxic and hypoxic periods, indicating that blood flow per se does not greatly alter myogenic responses. When gut loops were perfused with pulsatile arterial pressure, myogenic responses occurred more than twice as frequently as during nonpulsatile pefusion and they had a greater magnitude. The results are consistent with the observation that vascular smooth muscle is stimulated not only by steady stretch but also by the rate of stretch. The results also suggest that the arterial pressure pulse should be considered in the design and interpretation of future studies of local circulatory control.

UI MeSH Term Description Entries
D007422 Intestines The section of the alimentary canal from the STOMACH to the ANAL CANAL. It includes the LARGE INTESTINE and SMALL INTESTINE. Intestine
D008297 Male Males
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
D010101 Oxygen Consumption The rate at which oxygen is used by a tissue; microliters of oxygen STPD used per milligram of tissue per hour; the rate at which oxygen enters the blood from alveolar gas, equal in the steady state to the consumption of oxygen by tissue metabolism throughout the body. (Stedman, 25th ed, p346) Consumption, Oxygen,Consumptions, Oxygen,Oxygen Consumptions
D012039 Regional Blood Flow The flow of BLOOD through or around an organ or region of the body. Blood Flow, Regional,Blood Flows, Regional,Flow, Regional Blood,Flows, Regional Blood,Regional Blood Flows
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
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
D005260 Female Females
D006706 Homeostasis The processes whereby the internal environment of an organism tends to remain balanced and stable. Autoregulation

Related Publications

A P Shepherd
January 2003, Hypertension (Dallas, Tex. : 1979),
A P Shepherd
January 1973, Otolaryngologia polska = The Polish otolaryngology,
A P Shepherd
January 1960, Trudy Leningradskogo sanitarno-gigienicheskogo meditsinskogo instituta,
A P Shepherd
June 1988, Soins; la revue de reference infirmiere,
A P Shepherd
May 1948, The British journal of ophthalmology,
A P Shepherd
May 1948, The British journal of ophthalmology,
Copied contents to your clipboard!