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Seasonal variations in the nycthemeral rhythm of plasma melatonin in the camel (Camelus dromedarius).
J Pineal Res. 2005 Sep; 39(2):121-8.JP

Abstract

Seasonal changes in the pattern of plasma melatonin were investigated in two groups of camels (Camelus dromedarius): 11 adult and six young camels. Animals were subjected to the outdoor conditions of a desert environment. Blood samples were taken at regular intervals of about 3 hr (added to particular samples at 1 hr before then 30 min and 1 hr after sunset, and 1 hr before and 1 hr after sunrise) for 24 hr at both solstices and equinoxes of the year. The plasma melatonin levels steeply increased soon after sunset and remained elevated throughout all the night. Then, melatonin concentrations progressively declined shortly before sunrise and returned to daytime basal levels 1 hr later. There was no seasonal variation in the amplitude or in the offset of the melatonin peak or in the daytime basal levels. The onset of the nocturnal peak was delayed by 2 hr in June at the summer solstice (P < 0.05), which can be related to the changes in night length between the two solstices. A significant effect of age was observed in all seasons. Melatonin levels were higher in the young camel group (fall equinox: P < 0.001; spring equinox: P < 0.01; winter solstice: P < 0.01; summer solstice: P < 0.05). The pattern of melatonin secretion in the camel showed a significant seasonal variation parallel to the photoperiodic changes of the year. The observed decline of melatonin levels during an extra-light pulse in the middle of the night indicates the light control of melatonin synthesis. It is not yet known if, in this low latitude desert region, the seasonal breeding period of the camel is cued by the photoperiod. The data obtained, however, clearly demonstrate that the camel has the capacity to follow and to integrate photoperiodic changes through melatonin changes.

Authors+Show Affiliations

Département d'Anatomie Comparée, Institut Agronomique et vétérinaire Hassan II, Rabat, Morocco.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

16098088

Citation

El Allali, K, et al. "Seasonal Variations in the Nycthemeral Rhythm of Plasma Melatonin in the Camel (Camelus Dromedarius)." Journal of Pineal Research, vol. 39, no. 2, 2005, pp. 121-8.
El Allali K, Achaaban MR, Vivien-Roels B, et al. Seasonal variations in the nycthemeral rhythm of plasma melatonin in the camel (Camelus dromedarius). J Pineal Res. 2005;39(2):121-8.
El Allali, K., Achaaban, M. R., Vivien-Roels, B., Bothorel, B., Tligui, N. S., & Pévet, P. (2005). Seasonal variations in the nycthemeral rhythm of plasma melatonin in the camel (Camelus dromedarius). Journal of Pineal Research, 39(2), 121-8.
El Allali K, et al. Seasonal Variations in the Nycthemeral Rhythm of Plasma Melatonin in the Camel (Camelus Dromedarius). J Pineal Res. 2005;39(2):121-8. PubMed PMID: 16098088.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Seasonal variations in the nycthemeral rhythm of plasma melatonin in the camel (Camelus dromedarius). AU - El Allali,K, AU - Achaaban,M R, AU - Vivien-Roels,B, AU - Bothorel,B, AU - Tligui,N S, AU - Pévet,P, PY - 2005/8/16/pubmed PY - 2005/10/21/medline PY - 2005/8/16/entrez SP - 121 EP - 8 JF - Journal of pineal research JO - J Pineal Res VL - 39 IS - 2 N2 - Seasonal changes in the pattern of plasma melatonin were investigated in two groups of camels (Camelus dromedarius): 11 adult and six young camels. Animals were subjected to the outdoor conditions of a desert environment. Blood samples were taken at regular intervals of about 3 hr (added to particular samples at 1 hr before then 30 min and 1 hr after sunset, and 1 hr before and 1 hr after sunrise) for 24 hr at both solstices and equinoxes of the year. The plasma melatonin levels steeply increased soon after sunset and remained elevated throughout all the night. Then, melatonin concentrations progressively declined shortly before sunrise and returned to daytime basal levels 1 hr later. There was no seasonal variation in the amplitude or in the offset of the melatonin peak or in the daytime basal levels. The onset of the nocturnal peak was delayed by 2 hr in June at the summer solstice (P < 0.05), which can be related to the changes in night length between the two solstices. A significant effect of age was observed in all seasons. Melatonin levels were higher in the young camel group (fall equinox: P < 0.001; spring equinox: P < 0.01; winter solstice: P < 0.01; summer solstice: P < 0.05). The pattern of melatonin secretion in the camel showed a significant seasonal variation parallel to the photoperiodic changes of the year. The observed decline of melatonin levels during an extra-light pulse in the middle of the night indicates the light control of melatonin synthesis. It is not yet known if, in this low latitude desert region, the seasonal breeding period of the camel is cued by the photoperiod. The data obtained, however, clearly demonstrate that the camel has the capacity to follow and to integrate photoperiodic changes through melatonin changes. SN - 0742-3098 UR - https://www.unboundmedicine.com/medline/citation/16098088/Seasonal_variations_in_the_nycthemeral_rhythm_of_plasma_melatonin_in_the_camel__Camelus_dromedarius__ DB - PRIME DP - Unbound Medicine ER -