COMPETITIVE PROTEIN-BINDING ASSAY OF PROGESTERONE IN BOVINE JUGULAR VENOUS PLASMA DURING THE OESTROUS CYCLE

M. SHEMESH, H. R. LINDNER, N. AYALON
1971 Reproduction  
A rapid radiometric assay based on thin-layer-chromatography and the competition by progesterone for binding sites on the corticosterone-binding globulin of human plasma was used to determine changes in the level of progesterone in peripheral bovine plasma during the oestrous cycle. The blood level (ng/ml, mean \ m=+-\ S.E.) of the hormone was minimal ( 0\ m=. \ 6\ m=+-\ 0\m=.\15to 0\ m=. \ 8\ m=+-\ 0\m=.\20) from Day \m=-\2 to +2 of the cycle (Day 0 = day of oestrus), rose steeply between Day
more » ... teeply between Day 3 and Day 7, and either continued to rise very slowly or maintained a plateau fluctuating about a mean of 5\ m=. \ 4\ m=+-\ 0\m=.\16 for 8 to 10 days, before declining; the most abrupt fall in plasma progesterone concentration occurred on Day \m=-\4 or \m=-\3. The results agreed well with control data obtained by sequential paper-and gas-chromatography (r = 0\m=.\93).
doi:10.1530/jrf.0.0260167 pmid:5105156 fatcat:pr76hvonnrcxbpfwvqroqpej6u