Abstract

This study compared changes in liver tryptophan oxygenase (TPO) activity in response to hydrocortisone, hematin and tryptophan administration to non-diabetic and diabetic (streptozotocin) rats. Hydrocortisone caused similar increases in apoenzyme (inactive), holoenzyme (heme-saturated) and total (holoenzyme + apoenzyme) TPO activities in non-diabetic and diabetic rats. The ability of hematin to increase total TPO activity was significantly less in diabetic rats. The largest differences between diabetic and non-diabetic rats were found with tryptophan which increased total TPO and holoenzyme activities 300% and 650% respectively in non-diabetic rats. However, tryptophan increased both apoenzyme (unchanged in non-diabetic rats) and holoenzyme activities by 300% in diabetic rats. These results indicate that in the diabetic state, the TPO-heme conjugation process is impaired, especially substrate mediated TPO-heme saturation.

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.