The determination of maternal and foetal rat plasma corticosterone concentration in late pregnancy by competitive protein binding analysis

Effect of Fetal Decapitation on Unbound Rat Plasma Corticosterone Concentration at the End of Pregnancy

“…(2) The question to what extent the maternal and fetal rat corticosterone can cross the placental barrier from the mother to the fetus or the reverse. These points have been previously discussed in two works [19,20] on rat total plasma corticosterone levels in late pregnancy. …”

“…Corticoste rone was determined with a protein-binding analysis [ 18] adapted to maternal and fetal rat plasma samples [20]. The source of corticosteroid-binding globulin was baboon plasma diluted to 8% in a Veronal buffer 0.1 M, pH 8.6; we also used adrenalcctomized female rat plasma diluted to 0.06% in the same Veronal buff er, which produced equivalent results.…”

“…Group I comprised intact animals sacrificed on days 16,17,18,19,20 and 21 of pregnancy. Group I la con sisted of animals sacrificed on day 21 of pregnancy, 3 days after decapitation [10] of 1 fetus in each uterine horn; group lib consisted of some mothers who were adrcnalectomi/.cd just before fetal decapitation.…”

Influence of photoperiod on the time of birth in the rat. IV. Effects of an imposed feeding rhythm

“…1980 ; Pechinot and Cohen, 1983). This is also true of the effects of feeding rhythms (Johnson and Levine, 1973 ;Krieger, 1974 ;Moberg et al, 1975 ;Krieger et al, 1977 ;Obled et al, 1977 ;Takahashi et al, 1977 ;Morimoto et al, 1979 ;Itoh et al, 1980 ;Kato et al, 1980 ;Miyabo et al, 1980).…”

Determination of corticosterone and 17-hydroxycorticosterone in plasma and urine samples by sweeping techniques using micellar electrokinetic chromatography

“…Corticosterone is a glucocorticoid that is produced by rodents; whereas 17-hydroxycorticosterone is produced by humans. Most previous studies have employed radioimmunoassay [15,16], fluorimetry [17,18], liquid chromatography-electrospray ionization mass spectrometry [19][20][21] and gas chromatography/negative ion chemical ionization mass spectrometry [22][23][24][25] for the measurement of corticosterone levels. Each of these methods has unique advantages and disadvantages with respect to sensitivity, precision and simplicity of use.…”