Reference

Differences between binding affinities of some antimuscarinic drugs in the parotid gland and those in the urinary bladder and ileum

Differences between binding affinities of some antimuscarinic drugs in the parotid gland and those in the urinary bladder and ileum. Nilvebrant, Lisbeth; Sparf, Bengt (Dep.Several substances are used for example 31610-87-4 and 77-19-0 which are their cas registry numbers. Pharmacol., KabiVitrum AB, Stockholm S-112 87, Swed.). Acta Pharmacol. Toxicol., 53(4), 304-13 (English) 1983. CODEN: APTOA6. ISSN: 0001-6683. DOCUMENT TYPE: Journal CA Section: 2 (Mammalian Hormones) Section cross-reference(s): 1 Possible differences between the muscarinic receptors in the guinea pig urinary bladder and those in the ileum and the parotid gland were investigated, using a receptor-binding technique. The affinities of 18 antimuscarinic drugs were indirectly derived from the ability to inhibit the receptor-specific binding of the radioligand 1-quinuclidinyl-phenyl-4-3H benzilate. The Hill coeffs. were close to unity, indicating that the drugs were bound to apparently uniform populations of receptors within each tissue. In contrast to traditional muscarinic antagonists, 4 drugs (oxybutynin [5633-20-5], dicyclomine [77-19-0], benzhexol [144-11-6], and pirenzepine [28797-61-7]) bound with a significantly higher affinity in the parotid gland than in the urinary bladder and ileum. A tendency towards reversed selectivity was found for secoverine [57558-44-8]. Evidently, differences in muscarinic receptors between tissues exist, e.g., smooth muscle compared with parotid gland, which can be detected only by certain antimuscarinic drugs. .

Studies on the metabolic fate of oxybutynin hydrochloride (1)

Studies on the metabolic fate of oxybutynin hydrochloride (1). Absorption, distribution and excretion in rats and dogs. Akimoto, Yoshio; Kobayashi, Hideko; Shinozaki, Yutaka; Urakubo, Goro (Sch. Pharm., Toho Univ., Funabashi 274, Japan). Iyakuhin Kenkyu, 15(4), 519-35 (Japanese) 1984. CODEN: IYKEDH. DOCUMENT TYPE: Journal CA Section: 1 (Pharmacology) The pharmacokinetics of oxybutynin [5633-20-5] were investigated in the rat and dog after oral and i.v. administrations of the 14C-labeled compd. Blood levels increased rapidly and peak radioactivity was obsd. at 1 h after oral administration; thereafter, the level decreased very gradually in both species. After oral administration to the rat, the highest concn. of radioactivity was noted in the gastrointestinal tract, and high levels were obsd. in the liver and kidneys 1-24 h after dosing. No significant radioactivity was obsd. in other internal organs, and the concn. in the central nervous system was very low. Radioactivity was excreted mainly in feces in the rat, but roughly equally in urine and feces in the dog. Transfer of radioactivity to the bile was prominent after both oral and i.v. administrations, and the labeled compd. showed substantial enterohepatic circulation. The pharmacokinetics of oxybutynin during pregnancy and lactation were also studied in rats.