Detail of "59170-23-9"

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Isoproterenol antagonism of cardioselective beta-adrenergic blocking agents: a comparative study of human and guinea pig cardiac and bronchial beta-adrenergic receptors

Isoproterenol antagonism of cardioselective beta-adrenergic blocking agents: a comparative study of human and guinea pig cardiac and bronchial beta-adrenergic receptors. Harms, Herman H. (Dep. Clin. Pharmacol., Free Univ., Amsterdam, Neth.). J. Pharmacol. Exp. Ther., 199(2), 329-35 (English) 1976. CODEN: JPETAB. DOCUMENT TYPE: Journal CA Section: 1 (Pharmacodynamics) Section cross-reference(s): 13 Some pA2 values against d.c.-isoproterenol sulfate were detd.Several reagents with their cas registry numbers 37517-30-9 and 54340-62-4 are used here. for a no. of cardioselective and noncardioselective .beta.-adrenergic receptor blocking agents using a human and guinea pig isolated atrial and bronchial or tracheal prepns. to study possible species differences. No significant differences in pA2 values were found for 9 .beta.-blockers on bronchial or tracheal .beta. adrenergic receptors of both species. With respect to atrial .beta.-adrenergic receptors, lower pA2 values for human prepns. were found for tolamolol (I) [38103-61-6] and CI 775 [59170-23-9]. These are the only 2 agents in the series that derive their cardioselectivities from specific N substituents. The different potencies of only these 2 compds. in antagonizing the effect of isoproterenol on atrial .beta.-adrenergic receptors of both species suggest a difference in an accessory receptor area close to the site that interacts with the N atom of .beta.-adrenergic agents. .

Corneal penetration behavior of b-blocking agents

Corneal penetration behavior of b-blocking agents. II: Assessment of barrier contributions. Huang, Hong Shian; Schoenwald, Ronald D.; Lach, John L. (Coll. Pharm., Univ. Iowa, Iowa City, IA 52242, USA). J. Pharm. Sci., 72(11), 1272-9 (English) 1983. CODEN: JPMSAE. ISSN: 0022-3549. DOCUMENT TYPE: Journal CA Section: 1 (Pharmacology) Rabbit corneas were excised and mounted in a chamber to det. the permeability characteristics of a group of b-blocking agents. By measuring the permeability rate of each drug across intact cornea, stroma alone, epithelium-stroma, and stroma-endothelium, it was possible to det. the resistance to penetration for each corneal layer. The reciprocal of the sum of resistances for the epithelium, stroma, and endothelium equaled the exptl. detd. permeability coeff. for the intact cornea (104%). Thus, the penetration of b-blocking agents through the excised rabbit cornea could be treated as 3 barriers in series. For hydrophilic compds., the epithelium was the rate-detg. barrier. The endothelium offered less resistance, whereas the stroma offered only very minimal resistance. The lipophilic compds. penetrated the excised cornea more rapidly. However, the stroma became rate-detg. for the most lipophilic compds. 38363-40-5 and 29122-68-7 are also in the experiment. (penbutolol [38363-40-5], bufuralol [54340-62-4], bevantolol [59170-23-9], and propranolol [525-66-6]). Although the octanol-buffer (pH 7.65) distribution coeff. of these compds. varied over a 4-fold logarithmic range, the permeability coeff. was considered nearly const. [3.4 ′ 10-5 cm/s] for stroma. Also, the ratio of tortuosity to porosity for the stromal layer was 1.58. These results suggest that a drug diffuses through an aq. medium of gel-like mucopolysaccharide interspersed between a matrix of collagen fibrils. From further analyses, the intra- and intercellular pathways for epithelium and endothelium were added to the model, resulting in a sigmoidal representation of the permeability coeff. vs. the distribution coeff. However, the intercellular (pore) pathway could not be adequately quantified because of the variation in the data for very hydrophilic compds. .