Isoxsuprine-d6 (hydrochloride)

Isoxsuprine-d₆ is intended for use as an internal standard for the quantification of isoxsuprine by GC- or LC-MS. Isoxsuprine is an adrenergic receptor modulator that has α-adrenergic receptor (α-AR) antagonist and β-AR agonist properties.^1,2 It induces vasodilation of isolated equine common digital artery strips precontracted with norepinephrine, indicating an α-AR effect, and induces relaxation of isolated fowl cecum, an effect that can be blocked by the β-AR antagonist propranolol .^2,3 Isoxsuprine has antinociceptive effects in an acetic acid writhing test in mice.⁴ It also inhibits oxytocin-induced contractions in isolated rat uterus (IC₅₀ = 9.15 µM).⁵ It delays labor onset in rats by 31.63 hours when administered at a dose of 10 mg/kg per day on days 13 to 21 of gestation but increases heart rate with increasing concentration.

1.Cook, P., and James, I.Cerebral vasodilators (second of two parts)N. Engl. J. Med.305(26)1560-1564(1981) 2.Belloli, C., Carcano, R., Arioli, F., et al.Affinity of isoxsuprine for adrenoreceptors in equine digital artery and implications for vasodilatory actionEquine Vet. J.32(2)119-124(2000) 3.Ekert, R.S., and Macallister, C.G.Isoxsuprine hydrochloride in the horse: A reviewJ. Vet. Pharmacol. Ther.25(2)81-87(2002) 4.Bentley, G.A., and Starr, J.The antinociceptive action of some β-adrenoceptor agonists in miceBr. J. Pharmacol.88(3)515-521(1988) 5.Viswanathan, C.L., Kodgule, M.M., and Chaudhari, A.S.Design, synthesis and evaluation of racemic 1-(4-hydroxyphenyl)-2-[3-(substituted phenoxy)-2-hydroxy-1-propyl]amino-1-propanol hydrochlorides as novel uterine relaxantsBioorg. Med. Chem. Lett.15(15)3532-3535(2005)