Abstract

The pharmacokinetics of TRH and its metabolite deamido-TRH (TRH-OH) were evaluated and compared. After a 60- to 90-min infusion of the appropriate peptide into rats, the MCR, half-life of disappearance (t 1/2), and volume of distribution were calculated. The MCR of TRH averaged 4 ml/min, whereas that of TRH-OH was 6.5 ml/min. The serum concentrations of both TRH and TRH-OH decreased in a biexponential manner after stopping the corresponding peptide infusions. The t 1/2 values were 2.4 and 3.9 min for the initial phase of disappearance and 14.1 and 20.6 min for the later phase of disappearance for TRH and TRH-OH, respectively. The volume of distribution of TRH-OH was twice that of TRH. The fractional conversion rate of TRH to TRH-OH, based on serum TRH-OH concentrations measured during TRH infusions, was 0.7-1.4%. Less than 1 ng TRH-OH was excreted in the urine during the last 30 min of TRH infusion. The rapid clearance of TRH-OH and low fractional conversion of TRH to TRH-OH, as measured in serum, suggest that little TRH secretion will be reflected in serum TRH-OH concentrations.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.