Dynamics of the progesterone and cholesterol concentrations within the bovine corpus luteum cavity.

The aim of this study was to examine the concentrations of progesterone (P4) and cholesterol (CHOL) in fluid of cavitary corpus luteum (CL) and in serum of dairy cattle. Cavitary corpora lutea, collected from cows at a local abattoir, were divided in four stages of development, based on days of the estrous cycle (stage I: 1-4days; stage II: 5-10days; stage III: 11-17days; stage IV: 18-20). Fluid of the their cavity was aspirated and P4 and CHOL concentrations were evaluated. The concentrations of P4 in CL cavity fluids were very high (1640-4666.67ng/mL) and showed a peak at the stage III. CHOL values were similar to those of serum and the highest levels were found in the stage I.