On some physiological actions of ergot

Abstract

A PRELIMINARY note on the phenomena dealt with more completely in this paper was entitled, " The Physiological Action of Chrysotoxin'." Since the date of that publication further experiment has shown that the action is due to a principle, or combination of principles, which, by the aid of the physiological test, can be recognised in the various substances for which the title of "active principle" has been claimed, and indeed in all preparations of ergot possessing therapeutic activity. The active resin extracted from chrysotoxin, and called by Jacobj2 " sphacelotoxin," gives the effect in doses of a few milligrammes. So also do preparations corresponding in mode of extraction and solubility to the " cornutine" of Kobert, and differing from that substance only in their failure to elicit the spasms in frogs, described by Kobert3 as characteristic-a failure by no means unique in the experience of those who have worked with "cornutine" since Kobert. A resinous substance separated from commercial ergotinine also gives the reaction very typically and in small dosages; while, in larger quantities, many specimens of the ordinary pharmacopceial extracts produce the same effects, complicated only by the' presence of depressant impurities.These facts make it impossible to speak of the action any longer as that of chrysotoxin. On the other hand, the wide acceptance of Kobert's4 view as to the difference between spbacelotoxin (in -sphacelinic acid) and cornutine would render the attribution of the effects to either of those substances misleading. The introduction of new names on the strength of physiological results, and in default of chemical isolation of principles, would inevitably add to the existing confusion, 1

Effects of cardioselective and nonselective beta-adrenergic blockade on the performance of highly trained runners

“…The exercise was terminated because of (16) The blood pressure response was (17) ST-T changes: (18) Arrhythmias: (19) …”

Transformation of Adrenergic Receptors in the Myocardium

“…The ergotamine-resistant motor innervation of the mammalian myocardium has always been a puzzle to investigators attempting to differentiate adrenergic receptors pharmacologically (Dale, 1906;Lands, 1949).…”

“…The possible existence of a humoral receptor-modifying factor allows a reassessment of the receptor (Dale, 1906;Ahlquist, 1948) and the humoral theories (Cannon and Rosenblueth, 1933) of differential adrenergic responses. Either theory can explain direct adrenergic effects on various organs, but the humoral theory of Cannon and Rosenblueth has been largely abandoned because the postulated mediator + sympathin l or E complexes have not been identified.…”

“…In Ahlquist's theory excitatory responses in most smooth muscles and the secretory response of glands are believed to be mediated by areceptors, whereas inhibitory responses and the motor response of the mammalian heart are generally connected with s-receptor activity (Ahlquist, 1966). Among the more controversial organs are the gut, where both type of receptors seem to be involved in the inhibitory response to catecholam ines (Ahlquist and Levy, 1959), and the uterus, whose response is largely dependent on the species and the hormonal status of the animal (Dale, 1906;Greefe and Holtz, 1951;Tothi11, 1967). There are c1aims that venoconstr iction is mediated through s-adrenergi c receptors (Kaiser et ~., 1964) and the presence of a-receptor activity in the myocardium has also been demonstrate d (see page 34).…”

Analysis of the Adrenergic Receptors in the Urinary Tract of Dog

“…As early as 1906 Dale (1) reported that adrenaline causes relaxation of detrusor muscle and contraction of the vesical sphincter. However, the response of ureter to sympatho mimetic amines is indefinite; some experiments indicate that the motility and tone of the ureter are lessened (2) while in the rabbit Ahlquist (3) observed a stimulant effect of the amines on the ureter.…”