Sharon A. Birk

Dynamics of human placental lactogen

Abstract A double antibody radioimmunoassay procedure was set up to measure the human placental lactogen (HPL) in the blood of normal pregnant women. By the use of this technique the dynamics of this protein were studied. It was found that the content of HPL was the same in serum and plasma and that the blood content did not change with time of day, activity of the subject, or blood glucose level. There is a progressive rise in the blood HPL content during normal pregnancy and the level of HPL at term is not related to either the placental weight or the infant birth weight. The HPL does not cross the placental barrier and it is rapidly cleared from the maternal circulation after delivery with a half-life of only 29 minutes.

FACTORS INFLUENCING THE DYNAMICS OF GONADOTROPIN RESPONSE FOLLOWING BOLUS INFUSION OF LUTEINIZING HORMONE-RELEASING FACTOR IN WOMEN WITH MENSTRUAL ABNORMALITIES

Thirty-five women with menstrual abnormalities were given 100 microng of luteinizing hormone-releasing hormone (LHRH) by bolus intravenous injection in an attempt to simplify and quantitate the usefulness of this test in clinical management. Peak and total gonadotropin responses are highly correlated. Peak and total LH are significantly related to basal LH but no similar relationship could be established for follicle-stimulating hormone (FSH). There is no association between gonadotropin response and prolactin levels or body weight. Basal estradiol levels are inversely related to FSH response but not to LH response. It is concluded that the use of an intravenous 100-microng bolus of LHRH is of little use as a clinical test for the gynecologic endocrine patient.