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Biomedical subjects

H Selye

Publications and source records attributed to H Selye.

At least 37 records · Page 2Linked to original sources
PubMed1976

Regulation of resistance to various toxicants by PCN (pregnenolone-16alpha-carbonitrile) and thyroxine.

In rats, PCN (the most potent catatoxic steroid known to date) at the usual dose level powerfully inhibited the toxicity of antazoline, carbamazepine, cocaine, guanethidine, ibuprofen, ketamine, LSD, nembutal and reserpine, whereas (except in the case of nembutal) thyroxine sensitized the animals to intoxication with these same compounds. Even much lower doses of PCN or thyroxine exerted similar but weaker effects. PCN-induced resistance to the various substrates was generally not altered by concurrent administration of thyroxine but in a few cases its protective action was partially or totally inhibited, depending upon the respective dose levels of both compounds.

Animals↗
PubMed1976

Effect of pregnenolone-16alpha-carbonitrile on the rat liver.

In female rats, pregnenolone-16alpha-carbonitrile [PCN (a known microsomal enzyme inducer)] augmented liver weight and significantly increased hepatic protein, total lipid, phospholipid and ATP concentrations. These changes were correlated with hepatic drug-metabolizing enzyme induction. PCN did not alter body weight, or water, ash, triglyceride and cholesterol levels in the liver, but caused a mild reduction of hepatic glycogen.

Adenosine Triphosphate↗
PubMed1975

Confusion and controversy in the stress field.

An attempt is made to further clarify present areas of controversy in the stress field, in response to a two-part article by Dr. John W. Mason which concludes in this issue of the Journal of Human Stress. The author tries to elucidate each source of confusion enumerated by Dr. Mason. The continued use of the word "stress" for the nonspecific response to any demand is deemed most desirable. The once vague term can now be applied in a well-defined sense and is accepted in all foreign languages as well, including those in which no such word existed previously in any sense. Subdivision of the stress concept has become necessary as more recent work has led to such notions as "eustress," "distress," "systemic stress" and "local stress." Confusion between stress as both an agent and a result can be avoided only by the distinction between "stress" and "stressor". It is explained that the stress syndrome is--by definition--nonspecific in its causation. However, depending upon conditioning factors, which can selectively influence the reactivity of certain organs, the same stressor can elicit different manifestations in different individuals.

Adaptation, Psychological↗
PubMed1975

3Beta-hydroxy-20-oxo-pregn-5-ene-16 alpha-carbonitrile, a potent catatoxic steroid devoid of an abortifacient effect.

PCN (3beta-Hydroxy-20-oxo-pregn-5-ene-16alpha-carbonitrile), a potent catatoxic steroid devoid of all other classic hormonal properties, given in doses amply sufficient to induce hepatic drug-metabolizing enzymes and inhibit the anesthesia caused by massive amounts of progesterone in pregnant rats, did not modify: 1. the pregnant:mated ratio, 2. the length of gestation, 3. the number of implantation sites, and 4. the size of the litter. The viability and postpartum development of the offspring were normal, as judged by gross macroscopic examination. PCN had no adverse effects on pregnancy after hypophysectomy (day 12), or ovariectomy (day 8) in rats treated with maintenance doses of progesterone and estrone. It would therefore appear that the pregnancy-maintaining capacity of endogenous or exogenous steroids (administered as substitution therapy following the glandular extirpations) was not altered by PCN and that hypothalamo-hypophyseal regulatory mechanisms were not responsible for the failure of the steroid to provoke abortion. As judged by our in vivo experiment, this pure hepatic microsomal exzyme inducer does not modify the steady state of steroid-dependent physiologic functions.

Abortifacient Agents↗
PubMed1975

Stress and distress.

I must ask the reader's indulgence for this article's concern with applications of the stress concept, which are distinct from, although related to clinical medicine. It has not been my object to deal with the way physicians have been aided by stress research in the practice of medicine--that information is already widely available. Rather, I have attempted to sketch briefly the history of the stress theory and to demonstrate how this information can help anyone, physician or layman, lead a more complete and satisfying life. The applications of the stress theory have been dealt with at length elsewhere. I believe that we can find within scientifically verified observations the basis of a code of behavior suited to our century. The great laws of nature that regulate the defenses of living beings against stress of any kind are essentially the same at all levels of life, from individual cells to entire complex human organisms and societies. It helps a great deal to understand the fundamental advantages and disadvantages of catatoxic and syntoxic attitudes by studying the biologic basis of self-preservation as reflected in syntoxic and catatoxic chemical mechanisms. When applied to everyday problems, this understanding should lead to choices most likely to provide us the pleasant eustress (from the Greek eu meaning good, as in euphoria) involved in achieving fulfillment and victory, thereby avoiding the self-destructive distress of frustration and failure. So the translation of the laws governing resistance of cells and organs to a code of behavior comes down to three basic precepts: 1. Find your own natural stress level. People differ with regard to the amount and kind of work they consider worth doing to meet the exigencies of daily life and to assure their future security and happiness. In this respect, all of us are influenced by hereditary predispositions and the expectations of our society. Only through planned self-analysis can we establish what we really want; too many people suffer all their lives because they are too conservative to risk a radical change by breaking with hiabits or traditions. 2. Altruistic egoism. The selfish (i.e., self-interested) hoarding of the goodwill, respect, esteem, support, and love of our neighbors is the most efficient way to give vent to our pent-up energy and to create a more enjoyable, beautiful, or useful environment.3. Earn thy neighbor's love. This motto--which is merely a rewording of the command to "love thy neighbor as thyself"--is compatible with man's natural structure, and although it is based on altruistic egoism, it could hardly be attacked as unethical. Who would blame the man who wants to assure his own homeostasis and happiness only by accumulating the treasure of other poeple's benevolence and love? Yet this makes him virtually unassailable, for nobody wants to attack and destroy those upon whom he depends.

Adaptation, Physiological↗
PubMed1975

Inhibition of the effects of alfathesin and other steroid anesthetics by catatoxic steroids in rats.

In rats, the sleeping time induced by overdosage with eight steroid anesthetics--alfathesin, 3-(3-oxo-17beta-hydroxy-19-nor-4-androsten-17alpha-yl)-propionic acid-lactone (SC-8109), 21-hydroxy=5alpha-pregnane-3,20-dione (P-234), 4-pregnene-3,11,20-trione (Bio.66), 17-hydroxy-3-oxo-4-androstene-17alpha-propionic acid-gamma-lactone(SC-5233),3alpha-hydroxy-5beta-pregnane-11,20-dione, 5beta-pregnane-3,11,20-trione (U-1373), and hydroxydione--was abolished or considerably reduced by a variety of catatoxic compounds, particularly 3beta-hydroxy-20-oxo-5-pregnene-16alpha-carbonitrile (PCN), 9alpha-fluoro-11beta,17-dihydroxy-3-oxo-4-androstene-17alpha-propionic acid potassium salt (CS-1), prednisolone, ethylestrenol and spironolactone. Phenobarbital and diphenylhydantoin, two non-steroidal stimulators of hepatic microsomal drug metabolism, were also highly effective. In contrast, triamcinolone, estradiol,progesterone, desoxycorticosterone and hydroxydione, which exert little or no catatoxic activity, failed to significantly diminish anesthesia or sedation.

Alfaxalone Alfadolone Mixture↗