Twenty-four-hour Variation of Plasma Leptin Concentration and Pulsatile Leptin Secretion in Cattle

Kawakita, Y.; Abe, H.; Hodate, K.

doi:2001.14.9.1209

Article

Animal Reproduction and Physiology

Asian-Australasian Journal of Animal Sciences 2001;14(9): 1209-1215.
https://doi.org/10.5713/ajas.2001.1209 Published online September 1, 2001.

Twenty-four-hour Variation of Plasma Leptin Concentration and Pulsatile Leptin Secretion in Cattle

Y. Kawakita, H. Abe, K. Hodate

Abstract

We conducted this study to investigate 24 h leptin profiles and to ascertain whether leptin secretion occurs in a pulsatile manner in cattle. Plasma leptin concentrations were measured every 10 min for 24 h in five Holstein steers aged 10 months. Simultaneously, feeding behavior was recorded every 5 min during this experiment. In two of the five cattle, leptin showed diurnal rhythmicity, which could be described by a cosine, with peaks between 15:00 and 16:00 and nadirs at around midnight. Pulsatile leptin release was quantified by model-free Cluster analysis. Plasma leptin showed a pulsatile pattern in all cattle, with an average number of pulses at 15 peaks/24 h. The daily number of pulses was not related to total time spent eating, ruminating or chewing. However, when divided into six 4 h time intervals, time spent ruminating was positively related with pulse number (p=0.05) in cattle showing no diurnal plasma leptin variation. These results suggest that cattle may have unique diurnal variation and pulsatile patterns of plasma leptin, differing from those of monogastric animals.

Keywords: Leptin; Circadian Rhythm; Cattle