Cardiovascular System
Abstract
The following significant findings made during the past year are summarized. The ability of the heart to adapt to stress requires an intact autonomic nervous system. Acute increases in arterial pressure may cause detrimental effects to the system by direct action on the heart, particularly if underlying myocardial disease is present. The ability of the heart to adapt to different heart rates appears to be an important factor in exercise or prolonged hypoxia. Relaxing systems are important in the action of antihypertensive drugs and perhaps in the etiology and maintenance of abnormal blood pressure states. Reserpine mediated electrolyte loss from vascular tissue is the result of urinary excretion of sodium, potassium and calcium and calcium excretion into the gut. A new type of supersensitivity was discovered and characterized in vascular smooth muscle initiated by cold temperature. Prostaglandins augment myocardial contractility by increasing intracellular calcium stores. Cerebellar inhibitory mechanisms, but not reticular or spinal inhibitory mechanisms, were markedly suppressed by hallucinogenic drugs. Bicuculline suppressed cerebellar inhibition, but also suppressed reticular and presynaptic inhibition. There is a marked difference in the degree of inhibition and the rate of recovery from the inhibition in various tissues of the rat due to the insecticide disulfoton. The use of microwave radiation to rapidly inactive brain enzymes has been found to be a remarkably useful technique in the study of central neurotransmitters. Acetylcholinesterase increases in the hippocampal formation of the rat brain during shock avoidance learning.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 04, 1971
- Accession Number
- AD0734407
Entities
People
- Arthur H. Briggs
Organizations
- University of Texas at Austin