Relaxing Action of Synthetic Antispasmodics on the Intestinal Smooth Muscle of Guinea Pig

Antiphosphodiesterase Activity and Nonspecific Smooth Muscle Relaxation Tested on Intestinal Smooth Muscles

“…Papaverine may be able to penetrate into and through smooth muscle membrane to inhibit phosphodiesterase, because most molecules exist as a nonionized form in physiological hydrogen ion concentrations. Aspaminol and benactyzine, however, did not inhibit phosphodiesterase activity in the taenia from the guinea pig caecum (8). And it has been also reported in the previous papers (6, 9) that the action of Aspaminol is not mediated by the increase in intracellular cyclic AMP.…”

“…On the other hand, As parninol (1, 1-diphenyl-3-piperidinobutanol hydrochloride, Kowa Co. Ltd., Japan) and henactyzine hydrochloride, synthetic antispasmodics, have a papaverine-like nonspecific relaxing action in high concentrations. These drugs have, however, been found to have little inhibitory effects on phosphodiesterase activity in concentrations which have a maxi mum antispasmodic action (7,8). Furthermore, Asparninol does not increase the intra cellular cyclic AMP in concentrations which have a relaxing action (6,9).…”

Effects of Papaverine, Benactyzine and D600 on Ca2+ efflux, determined by means of a Ca2+-selective electrode, from guinea pig taenia coli into a Ca2+-free physiological solution.

“…Non-specific antispasmodics such as papa verine and benactyzine have been divided into two groups according to their mecha nisms of action; potent, basic compounds or synthetic antispasmodics such as ben actyzine hydrochloride and 1.1-diphenyl-3 piperidinobutanol hydrochloride (Aspaminol), and weak basic compounds such as pap verine (1)(2)(3)(4).…”

Pharmacological Studies of Lycorenine, an Alkaloid of Lycoris Radiata Herb.: II. Effects of Blood Pressure in Rats and Dogs and the Mechanism of Tachyphylaxis to the Vasodepressor Action of Lycorenine in Rats

“…Since papaverine is a potent inhibitor of cyclic AMP-phosphodiesterase (2), relaxation of smooth muscle is considered to be partly due to an increase of intracellular levels of cyclic AMP. However, Aspaminol and Ca-blockers are found to have little in hibitory action on phosphodiesterase activity (3,4). Nonspecific inhibitory action of Aspaminol (5,6) and of Ca-blockers (7) can be decreased to a great extent by increasing the Ca-concentration in the bath fluid, while that of papaverine is only slightly increased.…”