The amount of cholesterol that circulates in the plasma as lipoproteins can be affected by the balance of cholesterol metabolism within and between the intestines and liver. In the present report, we describe a novel hypocholesterolemic agent and document its pharmacological effects in animal models of hypercholesterolemia. The oral administration of (3R,4S)-1,4-bis-(4-methoxyphenyl)-3-(3-phenylpropyl)-2-azetidinone (SCH 48461) reduced plasma cholesterol concentrations in cholesterol-fed hamsters, rats and rhesus monkeys with ED50s of 1, 2 and 0.2 mg/kg per day, respectively, SCH 48461 was also highly effective in reducing hepatic cholesteryl ester accumulation in cholesterol-fed hamsters and rats after 7 days of treatment. In one 3 week study, rhesus monkeys were fed a 0.25% cholesterol/22% saturated fat diet with or without SCH 48461. At the end of the 3 week period the control group's VLDL + LDL-cholesterol increased to 180 Mg/dl from a baseline of approximately 65 mg/dl while plasma apolipoprotein B levels had doubled. Animals treated daily with 1 mg/kg SCH 48461 maintained their baseline levels of VLDL + LDL-cholesterol, HDL-cholesterol, and plasma apolipoproteins B and A-I. After 3 weeks the diets of the two groups were switched. Within 1 week SCH 48461 (1 mg/kg per day) rapidly reversed the elevated VLDL + LDL-cholesterol levels of the previous control group to near baseline values. SCH 48461 exerted its hypocholesterolemic effect through the inhibition of cholesterol absorption. A dose of 10 mg/kg per day inhibited cholesterol absorption in cholesterol-fed hamsters by 68% while a similar reduction was achieved in chow-fed monkeys with 3 mg/kg per day. This latter dose inhibited cholesterol absorption in cholesterol-fed monkeys by 95%. Treatment of cholesterol-fed monkeys with 10 mg/kg per day SCH 48461 significantly increased fecal neutral sterol excretion (52 vs. 32 mg/kg) but had no effect on acidic sterol excretion. Using a 2-h absorption model in cholesterol-fed hamsters, SCH 48461 caused a 46% inhibition of unesterified [14C]cholesterol accumulation in the intestinal wall and a 90% inhibition of cholesteryl ester formation at a dose of 10 mg/kg. Similar data were observed when the plasma radioactivity was assessed, indicating inhibition of both free (61%) and esterified (85%) cholesterol appearance. In contrast, CI-976, a potent acyl-CoA:cholesterol acyltransferase (ACAT) inhibitor, did not affect the uptake of free cholesterol into the intestines while inhibiting cholesterol esterification (98% inhibition).(ABSTRACT TRUNCATED AT 400 WORDS)

Download full-text PDF

Source
http://dx.doi.org/10.1016/0021-9150(94)05499-9DOI Listing

Publication Analysis

Top Keywords

sch 48461
36
mg/kg day
20
cholesterol absorption
16
cholesterol-fed hamsters
16
vldl ldl-cholesterol
12
cholesterol
10
sch
9
0
9
hamsters rats
8
rhesus monkeys
8

Similar Publications

MetaSite: understanding metabolism in human cytochromes from the perspective of the chemist.

J Med Chem

November 2005

Laboratory for Chemometrics and Cheminformatics, Department of Chemistry, University of Perugia, Via Elce di Sotto 10, I-06123 Perugia, Italy.

Identification of metabolic biotransformations can significantly affect the drug discovery process. Since bioavailability, activity, toxicity, distribution, and final elimination all depend on metabolic biotransformations, it would be extremely advantageous if this information could be produced early in the discovery phase. Once obtained, this information can help chemists to judge whether a potential candidate should be eliminated from the pipeline or modified to improve chemical stability or safety of new compounds.

View Article and Find Full Text PDF

Some novel substituted azetidin-2-ones (5-8) were synthesized via [2 + 2] cycloaddition reactions of imines and ketenes and evaluated for their ability to prevent diet and diabetes induced hypercholesterolemia. The test compounds 5a and 7a significantly (p < 0.01) inhibited the rise in serum total cholesterol induced by peanut oil (5.

View Article and Find Full Text PDF

Beta-lactam cholesterol absorption inhibitors.

Curr Med Chem

July 2004

Discovery Chemistry-CNS/CV, Schering-Plough Research Institute, 2015 Galloping Hill Rd., MS 2800, Kenilworth, NJ 07033, USA.

beta-Lactams have recently been identified as potent, highly efficacious cholesterol absorption inhibitors (CAIs). The discovery, SAR, and asymmetric synthesis of this class of hypolipidemic agents are described. Metabolism studies of the first clinical candidate, Sch 48461, led to the identification of a more potent second generation clinical candidate, Sch 58235 (ezetimibe) incorporating key structural elements of the active metabolites.

View Article and Find Full Text PDF

The discovery of ezetimibe: a view from outside the receptor.

J Med Chem

January 2004

Cardiovascular and CNS Medicinal Chemistry Department, Schering-Plough Research Institute, 2015 Galloping Hill Road, Kenilworth, New Jersey 07033-0539, USA.

View Article and Find Full Text PDF

Ezetimibe for management of hypercholesterolemia.

Ann Pharmacother

June 2003

College of Pharmacy, University of Toledo, Toledo, OH, USA.

Objective: To review the primary literature describing the pharmacology of ezetimibe and clinical trials investigating its use in the management of hypercholesterolemia.

Data Sources: A MEDLINE search (1966-December 2002) was performed using SCH 48461, SCH 58235, ezetimibe, and 2-azetidinone as key words. English-language articles were identified and the references of these articles were used to further identify pertinent articles and abstracts.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!