Disconnection between the early onset anorectic effects by C75 and hypothalamic fatty acid synthase inhibition in rodents.
In order to explore the relationship between the anorectic effect of 3-carboxy-4-octyl-2-methylenebutyrolactone (C75) and its pharmacokinetic properties, studies of in vivo and in vitro pharmacological characterization of C75 were performed in Fischer rats. In a quantitative measurement of food intake, we determined that appetite suppression by C75 takes place within 4 h. The C(max) for C75 of 2.6+/-1.5 microM was reached within 1-4 h after intraperitoneal administration at 30 mg/kg, a drug level that causes complete blockade of food intake. However, this concentration is substantially lower than the effective concentration used to inhibit rat fatty acid synthase enzyme activity in vitro (IC50: approximately 200 microM) and hypothalamic enzyme activity was found not to be inhibited by intraperitoneal administration of C75 at 30 mg/kg. Instead, a dramatic induction of c-Fos expression was found in area postrema. Collectively, these data indicate that the anorectic effect of C75 is independent of its inhibition of fatty acid synthase in the hypothalamus.
Rohrbach
Kenneth W
KW
Pharmaceutical Research Institute, Department of Metabolic Disease, Bristol-Myers Squibb Company, Princeton, NJ 08543, USA.
Han
Songping
S
Gan
Jinping
J
O'Tanyi
Eva J
EJ
Zhang
Hongwei
H
Chi
Cecilia L
CL
Taub
Rebecca
R
Largent
Brian L
BL
Cheng
Dong
D
D015107:4-Butyrolactone / Q000031:analogs & derivatives* / Q000097:blood / Q000493:pharmacokinetics / Q000494:pharmacology*; D000818:Animals; D001067:Appetite Depressants / Q000493:pharmacokinetics / Q000494:pharmacology; D001522:Behavior, Animal / Q000187:drug effects; D015152:Blotting, Northern; D003503:Cyclobutanes / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D064429:Fatty Acid Synthases / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D005277:Fenfluramine / Q000494:pharmacology; D005508:Food Deprivation; D007031:Hypothalamus / Q000187:drug effects* / Q000201:enzymology; D015151:Immunoblotting; D007274:Injections, Intraperitoneal; D007276:Injections, Intraventricular; D007700:Kinetics; D008297:Male; D010645:Phentermine / Q000494:pharmacology; D012313:RNA / Q000235:genetics / Q000378:metabolism; D011897:Random Allocation; D051381:Rats; D011916:Rats, Inbred F344; D013997:Time Factors
C406734:4-methylene-2-octyl-5-oxofuran-3-carboxylic acid; D001067:Appetite Depressants; D003503:Cyclobutanes; D005277:Fenfluramine; D012313:RNA; D010645:Phentermine; D064429:Fatty Acid Synthases; D015107:4-Butyrolactone; C058254:sibutramine