Ipriflavone pharmacokinetics in mutant Nagase analbuminemic rats

Orally Available Collagen Tripeptide: Enzymatic Stability, Intestinal Permeability, and Absorption of Gly-Pro-Hyp and Pro-Hyp

Collagen-derived small peptides, such as Gly-Pro-Hyp (GPH) and Pro-Hyp (PH), play a role in various physiological functions. Although collagen degrades in the gastrointestinal tract randomly and easily, it is not readily cleaved into bioactive peptides. To increase the bioavailability of bioactive peptides, a collagen tripeptide (CTP) was prepared from fish scales by the digestion method using collagenase from nonpathogenic Bacillus bacteria. It was demonstrated that Hyp-containing peptides-GPH and PH-were better absorbed and reached higher plasma levels after the oral administration of CTPs in rats compared to high molecular weight collagen peptide (H-CP). GPH and PH were stable in gastrointestinal fluid and rat plasma for 2 h, and GPH was able to be transported across the intestinal cell monolayer. These results suggest that the ingestion of CTP is an efficient method for taking bioactive peptides orally due to the enzymatic stability and intestinal permeability of GPH and PH.

Pharmacokinetics of drugs in mutant Nagase analbuminemic rats and responses to select diuretics

OBJECTIVES

To report (1) the pharmacokinetics of drugs that are mainly metabolized via hepatic cytochrome P450s (CYPs) or mainly excreted via the urine and bile, (2) the mechanism for the urinary excretion of drugs (such as glomerular filtration or renal active secretion or re-absorption), and (3) the diuretic effect of some loop diuretics in mutant Nagase analbuminaemic rats (NARs), an animal model for human familial analbuminaemia based on the pharmacokinetics of drugs reported in the literatures.

KEY FINDINGS

In NARs, the changes in the time-averaged non-renal clearances (CL(NR)s) of drugs that are mainly metabolized via CYPs were explained in terms of changes in the hepatic intrinsic clearance (mainly because of changes in CYPs), free (unbound) fractions of drugs in the plasma (fp) and hepatic blood-flow rate (QH) depending on the hepatic excretion ratios of drugs.

SUMMARY

The CL(NR) changes of drugs mainly metabolized via hepatic CYPs can be sufficiently explained by the three earlier mentioned factors. The plasma albumin (furosemide) or globulin (azosemide, bumetanide and torasemide) binding affects their diuretic effects.