-transparent.png){kind=logo}
There have been three articles in the clinical literature of ergonovine maleate-induced bronchospasm. The effect of the alkaloid on isolated canine tracheal smooth muscle was analyzed to investigate the mechanism of ergonovine-induced airway smooth muscle contraction. Both ergonovine and 5-hydroxytryptamine (5HT, serotonin) contracted the smooth muscle preparations with EC50s of 1.35 X 10(-8) mol/L and 5.06 X 10(-7) mol/L, respectively. The maximal contractile response observed with ergonovine was approximately 30% less than that observed with 5HT. Methysergide competitively blocked both ergonovine and 5HT responses with similar calculated pKB values (8.33 against ergonovine and 8.46 against 5HT) and also similar pA2 values determined by Schild plots (8.50 and 8.45, respectively). The relative affinity and efficacy of ergonovine versus 5HT were determined by use of a concentration of the irreversible antagonist, phenoxybenzamine, which partially blocked receptor sites. The calculated affinity of ergonovine was about 16 times higher than that of 5HT. The relative efficacy at EC100 for ergonovine was 0.2, but at EC10 it was 41.9 (5HT efficacy = 1). Ergonovine 10(-9) or 10(-8) mol/L shifted the 5HT dose-response curve to the right without reducing the maximal response, but the shift was nonparallel. Blockade of muscarinic (atropine), alpha 1-adrenergic (prazosin), beta-adrenergic (propranolol), H1 (pyrilamine), or H2 (cimetidine) receptors did not alter ergonovine-induced contraction. These data indicate that ergonovine directly contracts canine tracheal smooth muscle as a result of its combination with 5HT receptors. This effect may result in precipitation of an asthmatic attack in susceptible individuals.
Y Sakamoto, and
J J Krzanowski, and
R F Lockey, and
R Duncan, and
J B Polson, and
A Szentivanyi
June 1989,
Nihon Kyobu Shikkan Gakkai zasshi,
Y Sakamoto, and
J J Krzanowski, and
R F Lockey, and
R Duncan, and
J B Polson, and
A Szentivanyi
November 1998,
The European respiratory journal,
Y Sakamoto, and
J J Krzanowski, and
R F Lockey, and
R Duncan, and
J B Polson, and
A Szentivanyi
January 2017,
Arerugi = [Allergy],
Y Sakamoto, and
J J Krzanowski, and
R F Lockey, and
R Duncan, and
J B Polson, and
A Szentivanyi
July 1983,
Journal of applied physiology: respiratory, environmental and exercise physiology,
Y Sakamoto, and
J J Krzanowski, and
R F Lockey, and
R Duncan, and
J B Polson, and
A Szentivanyi
April 1986,
Archives internationales de pharmacodynamie et de therapie,
Y Sakamoto, and
J J Krzanowski, and
R F Lockey, and
R Duncan, and
J B Polson, and
A Szentivanyi
April 2006,
Inflammation research : official journal of the European Histamine Research Society ... [et al.],
Y Sakamoto, and
J J Krzanowski, and
R F Lockey, and
R Duncan, and
J B Polson, and
A Szentivanyi
January 2007,
British journal of pharmacology,
Y Sakamoto, and
J J Krzanowski, and
R F Lockey, and
R Duncan, and
J B Polson, and
A Szentivanyi
March 2003,
The international journal of biochemistry & cell biology,
Y Sakamoto, and
J J Krzanowski, and
R F Lockey, and
R Duncan, and
J B Polson, and
A Szentivanyi
February 1995,
Journal of applied physiology (Bethesda, Md. : 1985),
Y Sakamoto, and
J J Krzanowski, and
R F Lockey, and
R Duncan, and
J B Polson, and
A Szentivanyi
August 2019,
American journal of physiology. Lung cellular and molecular physiology,
