Circadian variation of DSIP-like material in rat plasma.
Fischman. A J AJ; Kastin. A J AJ; Graf. M V MV
Key Findings
- DSIP‑like levels in rat blood follow a circadian pattern, peaking around 5 PM.
- The peak timing mirrors that of corticosterone, a stress‑related hormone.
- Continuous illumination eliminates the DSIP‑like rhythm, suggesting light influences its cycle.
Practical Outcomes
- For most biohackers, this study offers limited direct action because it’s done in rats and doesn’t provide dosage or protocol guidance for humans. It does suggest that DSIP might be tied to the body’s natural hormone cycles and could be affected by light exposure, but more human research is needed before applying it to sleep or performance strategies.
Summary
In rats, a substance similar to the sleep‑inducing peptide DSIP shows a daily rhythm that matches the hormone corticosterone, peaking in the late afternoon and dropping at night. Constant light disrupts this rhythm, hinting the two may be linked.
Abstract
Levels of delta-sleep-inducing peptide-like immunoreactivity (DSIP-LI) in rat plasma were measured by radioimmunoassay and found to exhibit a circadian rhythm that parallelled the normal rhythm for corticosterone. The maximal plasma levels of both substances were observed to occur at about 1700h. The lowest concentrations of DSIP-LI and corticosterone were detected at 2400h and 1000h, respectively. Exposure to constant levels of illumination abolished the rhythm of DSIP-LI. It is possible that the temporal parallelism between the levels of DSIP-LI and corticosterone may represent a functional relationship between both compounds.
Study Information
pubmed
1984
1984-11-12T00:00:00.000Z
10.1016/0024-3205(84)90566-6
9
12