Actions of Nipradilol (K-351), a New α- and β-Adrenoceptor Blocker, on the Rabbit Portal Vein

Nanjo, Tamaki; Kitamura, Kenji

doi:10.1254/jjp.35.359

Cited by 12 publications

(9 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, we confirmed that a rela tively large dose of nipradilol did not signif icantly inhibit the KCl-induced vasocon striction in the doses used. These results were not in agreement with previous reports [3,15,16], Thus, we considered that differ ent results might be due to different vessel preparations and different procedures, and nipradilol might have no calcium antagonis tic action in the doses used.…”

Section: Discussioncontrasting

confidence: 94%

“…The a-adrenoceptorblocking action of nipradilol was approxi mately 5 times less potent than that of phen tolamine as reported by Uchida et al [4], They reported that nipradilol produced a glycerol trinitrate-like relaxant action on iso lated blood vessels previously contracted with by K+. It was reported that nipradilol slightly reduced the K-induced contraction in mesenteric artery [3] and in the rabbit portal vein [15], Kuo et al [16] suggested that nipradilol is involved in other inhibi tory actions in addition to a-adrenoceptor blockade, because high concentrations of ni pradilol strongly inhibited the contraction of dog mesenteric veins produced not only by noradrenaline but also by high potassium concentration or current-induced depolari zations. However, we confirmed that a rela tively large dose of nipradilol did not signif icantly inhibit the KCl-induced vasocon striction in the doses used.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Blocking Effects of Nipradilol on Vasoconstrictor Responses to Periarterial Nerve Stimulation and α-Adrenoceptor Agonists in Isolated and Perfused Canine Mesenteric Arteries

Chiba¹,

Tsukada²

1987

Pharmacology

View full text Add to dashboard Cite

The stainless steel cannula inserting method was used to observe effects of nipradilol and prazosin on responses to periarterial electrical nerve stimulation and intraluminal administration of noradrenaline or phenylephrine in isolated and perfused canine mesenteric arteries. With small doses, nipradilol slightly potentiated vasoconstrictor responses to noradrenaline, but not periarterial stimulation. With a relatively large dose, nipradilol almost uniformly suppressed both periarterial stimulation-induced and noradrenaline- or phenylephrine-induced vasoconstriction. On the other hand, prazosin inhibited noradrenaline-induced vasoconstriction at small doses but not periarterial nerve stimulation-induced vasoconstrictions. At any doses, prazosin strongly inhibited noradrenaline-induced constrictions more markedly than periarterial stimulation-induced constrictions. It is concluded that nipradilol has a dominant inhibitory property on periarterial nerve stimulation-induced constriction in isolated canine mesenteric arteries.

show abstract

Section: Discussioncontrasting

confidence: 94%

Section: Discussionmentioning

confidence: 99%

Blocking Effects of Nipradilol on Vasoconstrictor Responses to Periarterial Nerve Stimulation and α-Adrenoceptor Agonists in Isolated and Perfused Canine Mesenteric Arteries

Chiba¹,

Tsukada²

1987

Pharmacology

View full text Add to dashboard Cite

show abstract

“…Nipradilol is known to induce relaxation in vascular smooth muscle from various tissues including rabbit portal vein (Nanjo and Kitamura, 1984), dog coronary arteries (Sakanashi et al, 1984), and guinea pig thoracic aorta (Ohira et al, 1985). There are two different mechanisms involved in this relaxation.…”

Section: Discussionmentioning

confidence: 99%

Vasodilatory Effects of Nipradilol, an α- and β-adrenergic Blocker with Nitric Oxide Releasing Action, in Rabbit Ciliary Artery

Yoshitomi

Yamaji

Ishikawa

et al. 2002

Experimental Eye Research

View full text Add to dashboard Cite

“…· 1 -Adrenoceptor-blocking potencies of nipradilol did not differ between dog ocular arteries used in the present study. · 1 -and ß-adrenoceptor-blocking activities of nipradilol have also been reported in isolated peripheral arteries [20,21] and in the systemic circulation of anesthetized animals [22].…”

Section: Discussionmentioning

confidence: 84%

Effects of Nipradilol on Alpha-Adrenoceptor Function in Ocular Arteries

Okamura¹,

Fujioka²,

Ayajiki³

2002

Pharmacology

View full text Add to dashboard Cite

The effects of nipradilol, a drug used in the treatment of glaucoma, on the contractions induced by noradrenaline and phenylephrine in isolated dog central retinal, external and internal ophthalmic arteries and pig ciliary arteries were investigated. In dog ocular arteries treated with oxyhemoglobin (1.6 × 10^–5 mol/l) to adsorb nitric oxide, noradrenaline (2 × 10^–8 to 10^–5 mol/l) produced a concentration-related contraction which was markedly inhibited by prazosin but not by yohimbine. Nipradilol (10^–9 to 10^–7 mol/l) slightly but significantly inhibited the noradrenaline-induced contraction in a concentration-related manner, but the inhibitory potency and efficacy were much less than those of prazosin. However, nipradilol inhibited the phenylephrine-induced contraction with a similar PA₂ value of prazosin. In pig ciliary arteries treated with oxyhemoglobin, noradrenaline-induced contraction was slightly inhibited by prazosin but markedly inhibited by yohimbine. Nipradilol, similarly to timolol, did not inhibit, but rather tended to potentiate, the contraction elicited by noradrenaline. The contraction induced by phenylephrine was significantly inhibited by prazosin and nipradilol. It is concluded that nipradilol acts as an α₁-adrenoceptor antagonist (but not as an α₂-adrenoceptor antagonist) in the ocular arteries, which may partially explain its ocular-pressure-lowering mechanism. Taken together with the results of our previous studies, the potencies of the nipradilol-induced vascular actions in ocular arteries are found to be in the following order: β-adrenoceptor inhibition > α₁-adrenoceptor inhibition ≒ direct vasodilation via a release of nitric oxide.

show abstract

Actions of Nipradilol (K-351), a New α- and β-Adrenoceptor Blocker, on the Rabbit Portal Vein

Cited by 12 publications

References 16 publications

Blocking Effects of Nipradilol on Vasoconstrictor Responses to Periarterial Nerve Stimulation and α-Adrenoceptor Agonists in Isolated and Perfused Canine Mesenteric Arteries

Blocking Effects of Nipradilol on Vasoconstrictor Responses to Periarterial Nerve Stimulation and α-Adrenoceptor Agonists in Isolated and Perfused Canine Mesenteric Arteries

Vasodilatory Effects of Nipradilol, an α- and β-adrenergic Blocker with Nitric Oxide Releasing Action, in Rabbit Ciliary Artery

Effects of Nipradilol on Alpha-Adrenoceptor Function in Ocular Arteries

Contact Info

Product

Resources

About

Actions of Nipradilol (K-351), a New α- and β-Adrenoceptor Blocker, on the Rabbit Portal Vein

Cited by 12 publications

References 16 publications

Blocking Effects of Nipradilol on Vasoconstrictor Responses to Periarterial Nerve Stimulation and &alpha;-Adrenoceptor Agonists in Isolated and Perfused Canine Mesenteric Arteries

Blocking Effects of Nipradilol on Vasoconstrictor Responses to Periarterial Nerve Stimulation and &alpha;-Adrenoceptor Agonists in Isolated and Perfused Canine Mesenteric Arteries

Vasodilatory Effects of Nipradilol, an α- and β-adrenergic Blocker with Nitric Oxide Releasing Action, in Rabbit Ciliary Artery

Effects of Nipradilol on Alpha-Adrenoceptor Function in Ocular Arteries

Contact Info

Product

Resources

About

Blocking Effects of Nipradilol on Vasoconstrictor Responses to Periarterial Nerve Stimulation and α-Adrenoceptor Agonists in Isolated and Perfused Canine Mesenteric Arteries

Blocking Effects of Nipradilol on Vasoconstrictor Responses to Periarterial Nerve Stimulation and α-Adrenoceptor Agonists in Isolated and Perfused Canine Mesenteric Arteries