Abstract
In molting birds keratin synthesis is intense and continuous through day and night. Keratins are much richer in cystine than are most tissue proteins. We hypothesized that glutathione (γ-glutamylcysteinylglycine) helps to sustain feather synthesis and spare bodyprotein during overnight fasting by serving as a cysteine reservoir. To test this hypothesis, we measured the responses of liver and muscle glutathione and protein pools to various feeding schedules (cysteine supply) andperiods of overnight fasting (cysteine demand) in molting white-crowned sparrows. Our main purpose was to ascertain whether these pools change passively or are instead regulated in relation to cysteine need in the postabsorptive state. During molt, significantly more liver glutathione and pectoralis protein were stored by day and utilized overnight than in postmolt. Liver glutathione and pectoralis protein were stored and utilized diurnally during molt in proportion to the duration of the overnight fast (12 h > 8 h > 4 h). Diurnal c...
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 callDisclaimer: 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.
