Circadian variations in biochemical markers of bone metabolism in horse of different age

Abstract

The author studied in thirty Thoroughbred horses the influence of age and gender on daily rhythms of serum osteocalcin (OC). The animals were divided into two groups. Group A: six male and six female 2 years old; Group B: six male, six female and six geldings 6 years old. They were housed individually in box-like stalls under natural photoperiod and environmental conditions. Blood samples were collected every 3 hours over a 48 hour period. Statistical differences of serum OC concentration due to different gender were observed in both Groups A and B. Daily rhythms of serum OC concentration were observed only in Group B, with nocturnal acrophase. In females the acrophase was statistically postponed for 1 hour compared to male and gelding. Male and female showed a more robust daily rhythm than the geldings. The results showed that blood sampling for determination of serum OC should be strictly standardized with regard to the time of the day.

State of the art on daily rhythms of physiology and behaviour in horses

“…Gender differences of peripheral steroid hormone concentration were observed in females when compared to males and geldings (Fletcher et al 2000). These hormones act on the steroid receptors located on the osteoblastic cells, and are probably responsible for differences in the osteocalcin serum level observed in male, female and gelding mature horses (Giannetto et al 2010). Mature and immature horses show different bone metabolism influencing the daily rhythm of osteocalcin.…”

The age of biomedicine: current trends in traditional subjects

“…Circadian vascular characteristics are sensitive markers of loads, including the rest-activity schedule (Cornélissen et al 2010a). Our awareness of blood characteristics the sampling for which should be strictly standardized with regard to the time of the day, is still increasing in both human and veterinary medicine (Berger 2008, Giannetto et al 2010.…”