Biomaterial Database

Pharmacokinetics of novel hexapeptides with neurotensin activity in rats. 1993

R Machida, and T Tokumura, and Y Tsuchiya, and A Sasaki, and K Abe

Tsukuba Research Laboratories, Eisai Co., Ltd., Ibaraki, Japan.

A high-performance liquid chromatographic method to determine (Me)Arg-Lys-Pro-Trp-tert-Leu-Leu (NT-2) with neurotensin (NT) activity in rat plasma was developed and a pharmacokinetic study was performed in rats. Quantitative analysis with high reproducibility was achieved for NT-2 over the concentration range of 1.14-500 ng/ml. (Me)Arg-Lys-Pro-Trp-tert-Leu-Leu-OEt (NT-1) was rapidly hydrolyzed to NT-2 in rat plasma at 37 degrees C. This degradation of NT-1 was observed as a pseudo first-order reaction, and the pseudo first-order rate constant was calculated to be 7.26 min-1 (t1/2 = 0.095 min). The pharmacokinetic profiles of NT-2 after intravenous administration of NT-1 at doses of 0.1 and 0.3 mg/kg were compatible with that of NT-2 after intravenous administration of NT-2 at 0.5 mg/kg. Range of the half-life of the terminal phase (t1/2 beta) of NT-2 was 0.36-0.53 h. The absolute bioavailabilities after oral administrations of NT-1 and NT-2 at a dose of 20 mg/kg were 0.61 +/- 0.17 (mean +/- S.E.) and 0.19 +/- 0.08%, respectively. It was found that NT-1 was more suitable for oral administration than NT-2.

UI	MeSH Term	Description	Entries
D007275	Injections, Intravenous	Injections made into a vein for therapeutic or experimental purposes.	Intravenous Injections,Injection, Intravenous,Intravenous Injection
D007421	Intestine, Small	The portion of the GASTROINTESTINAL TRACT between the PYLORUS of the STOMACH and the ILEOCECAL VALVE of the LARGE INTESTINE. It is divisible into three portions: the DUODENUM, the JEJUNUM, and the ILEUM.	Small Intestine,Intestines, Small,Small Intestines
D008297	Male		Males
D008969	Molecular Sequence Data	Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.	Sequence Data, Molecular,Molecular Sequencing Data,Data, Molecular Sequence,Data, Molecular Sequencing,Sequencing Data, Molecular
D009496	Neurotensin	A biologically active tridecapeptide isolated from the hypothalamus. It has been shown to induce hypotension in the rat, to stimulate contraction of guinea pig ileum and rat uterus, and to cause relaxation of rat duodenum. There is also evidence that it acts as both a peripheral and a central nervous system neurotransmitter.
D009842	Oligopeptides	Peptides composed of between two and twelve amino acids.	Oligopeptide
D002851	Chromatography, High Pressure Liquid	Liquid chromatographic techniques which feature high inlet pressures, high sensitivity, and high speed.	Chromatography, High Performance Liquid,Chromatography, High Speed Liquid,Chromatography, Liquid, High Pressure,HPLC,High Performance Liquid Chromatography,High-Performance Liquid Chromatography,UPLC,Ultra Performance Liquid Chromatography,Chromatography, High-Performance Liquid,High-Performance Liquid Chromatographies,Liquid Chromatography, High-Performance
D006207	Half-Life	The time it takes for a substance (drug, radioactive nuclide, or other) to lose half of its pharmacologic, physiologic, or radiologic activity.	Halflife,Half Life,Half-Lifes,Halflifes
D000284	Administration, Oral	The giving of drugs, chemicals, or other substances by mouth.	Drug Administration, Oral,Administration, Oral Drug,Oral Administration,Oral Drug Administration,Administrations, Oral,Administrations, Oral Drug,Drug Administrations, Oral,Oral Administrations,Oral Drug Administrations
D000595	Amino Acid Sequence	The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.	Protein Structure, Primary,Amino Acid Sequences,Sequence, Amino Acid,Sequences, Amino Acid,Primary Protein Structure,Primary Protein Structures,Protein Structures, Primary,Structure, Primary Protein,Structures, Primary Protein