TOTAL CHOLESTEROL, HIGH DENSITY LIPOPROTEINS (HDL) AND CORTISOL PLASMA LEVELS, AND THEIR BIORHYTMICITY, IN 24 HOURS, THROUGHOUT YEAR, IN IDEAL-POLWARTH RAMS

Abstract

To evaluate the mean plasma concentrations of total cholesterol (TC), high density lipoproteins (HDL) and cortisol, blood samples were collected of five Ideal-Polwarth rams, maintained at 22?53’S latitude, in semi-confinement, every two months throughout the year, by 24h period, with 2-hour intervals between colects. The TC, changed 40.70?1,11mg/dL (April) and 61.48?1,11mg/dL (December), between months, while HDL changed 22.16?0.23mg/dL (December) as 33.40?0.23mg/dL (February), but not make evident a circannual rhythm in this levels. The TC presented the lowest value at 16:30h (50.40?1.57mg/dL) and the highest value at 8:30h collect (54.67?1.57mg/dL); the HDL lowest level was at 10:30h (27.04?0.33mg/dL) and the highest level also at 8:30h collect (28.49?0.33mg/dL), however without permit circadian rhythm determination in your plasma concentrations. Similarly, the cortisol plasma concentrations, between collect months, presents variable, however without demonstrate circadian rhythm in this hormone secretion. In relation to different collection’s moments, throughout months, it wasn’t possible to define, by statistical analysis, a circadian rhythm of cortisol secretion. KEY WORDS: Ovine, adrenal hormone, biochemistry metabolites, circadian rhythm.