Plasma levels of SP1-like immunoreactive material (SP1) and progesterone throughout pregnancy and following RU 486-induced early abortion in the cynomolgus monkey (Macaca fascicularis).
A human-SP1 immunoassay was used to detect SP1-like material (SP1) in the plasma of cynomolgus monkeys. In 27 females remaining non-pregnant during a mating period of 4 months, SP1 was occasionally detected at a mean concentration of 2.5 ng/ml. In 14 non-pregnant females of subsequent proven fertility, SP1 was detected 20 days following unfertile mating at a mean concentration of 4.8 ng/ml in 86% of cycles. At day 20 of proven pregnancies, SP1 was at 12 ng/ml in 93% of these animals. SP1 levels during pregnancy increased in two steps, a slow rise between days 20 and 50, followed by an abrupt rise between days 50 and 60 and afterwards a plateau at 600 ng/ml. Seven other pregnant monkeys received 10 mg/kg of the antiprogestin RU 486 at 28 days. Four aborted and the others continued their gestation. SP1 was always dramatically depressed by this treatment; in animals with abortion failure, it remained at a low concentration for 3 months, then the normal concentration range was recovered. The assay of SP1-like material does not allow early diagnosis of pregnancy, however, it remains interesting as a follow-up parameter after 60 days. Also, antiprogestins appear to be useful tools to analyse the metabolism of SP1.
Germain
G
G
U262 INSERM, Maternité Baudelocque, Paris, France.
Mignot
T
T
Bischof
P
P
Mouren
M
M
Cédard
L
L
D000028:Abortion, Induced; D000818:Animals; D005260:Female; D005865:Gestational Age; D006207:Half-Life; D007124:Immunoenzyme Techniques; D008252:Macaca fascicularis; D015735:Mifepristone / Q000097:blood / Q000494:pharmacology*; D011247:Pregnancy; D011257:Pregnancy Proteins / Q000378:metabolism*; D011270:Pregnancy, Animal / Q000097:blood*; D011268:Pregnancy-Specific beta 1-Glycoproteins / Q000378:metabolism*; D011374:Progesterone / Q000097:blood*; D011863:Radioimmunoassay
D011257:Pregnancy Proteins; D011268:Pregnancy-Specific beta 1-Glycoproteins; D015735:Mifepristone; D011374:Progesterone