Abstract
The aim of this study was to develop a radioimmunoassay for the measurement of endogenous circulating melatonin concentrations in the Syrian hamster, and then to determine the effect of various photic manipulations upon this endocrine signal. In experiment 1, pineal-intact or pinealectomized adult male Syrian hamsters, housed under a long photoperiod (LD; 16 h light:8 h darkness) for 2 weeks, were then either maintained on LD or transferred to a short photoperiod (SD; 8 h light:16 h darkness) for a further 8 weeks. The profile of serum melatonin concentrations was determined from blood samples taken by cardiac puncture at intervals over a 24-h period. Radioimmunoassay revealed that daytime concentrations were at or below the limit of sensitivity of the assay (
| Original language | English |
|---|---|
| Pages (from-to) | 65-73 |
| Number of pages | 8 |
| Journal | Journal of Endocrinology |
| Volume | 136 |
| Issue number | 1 |
| Publication status | Published - 1993 |