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Estrone and estradiol levels in the ovarian venous blood from rats during the estrous cycle and pregnancy (1971)
| Content Provider | CiteSeerX |
|---|---|
| Author | Shaikh, Abubakar A. |
| Abstract | Estrone and estradiol measurements were made in rat ovarian vein plasma by radio-immunoassay using dextran coated charcoal for separation (Hotchkiss and Knobil, unpub-lished). Separation of the steroids was carried out by subjecting the ether extract of the plasma to phenolic partition and column chromatography (celite microcolumn). During the estrous cycle the estrogen secretion rate varied greatly. During diestrus the secretion rates of E1 and E2 were low. They had, however, risen sharply by the morning of proestrus. By 2100-2300 hr on the same day the levels again fell significantly, and then remained low during estrus. Secretion rates of E, and E, were similar early on Day 3 of pregnancy to the values seen at estrus. On Day 4 significant increases in secretion rates of both E, and E3 were observed the peak secretion of E1 and E, occurring between 14(E)-1600 hr. Estrogen secretion then dropped again to intermediate values and with minor fluctuations remained essentially unchanged until increases were again observed towards the end of pregnancy. The ratio of E,/E, varied from 1 to 7 throughout estrous cycle and pregnancy. The largest ratios were seen at the maximal rates of se:retion. in order to better understand the control of reproductive phenomena, a knowledge of the interrelationship of the secretion of steroid and pituitary hormones is essential. Our studies therefore have dealt with de-terminations of the relative concentrations of steroid and protein hormones in individual rats. The advent of radioimmunoassay for steroid and protein hormones (Abraham, 1969; Niswender et a!., 1968, 1969) has made it possible to measure these hormones in small samples of blood from individual animals. In order to efficiently utilize these blood samples for the measurement of steroids, a comprehensive method had to be developed, so that the different steroids could be measured using one extraction procedure. For the estrogens, phenolic partition (Baird, |
| File Format | |
| Journal | Biol. Reprod |
| Language | English |
| Publisher Date | 1971-01-01 |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
