Cervicovaginal peroxidases: markers of the fertile period.

The specific activity of guaiacol peroxidase was measured daily in human cervical mucus, vaginal fluids, and saliva during 45 cycles in 31 women. Also determined were basal body temperatures and serum hormones (luteinizing hormone [LH], estradiol, progesterone). The guaiacol peroxidase was extracted with 0.5 M CaCl2 and thus may be a different peroxidase from that obtained by noncalcium extraction procedures. The guaiacol peroxidase specific activity did not vary in the saliva during the cycle but fell sharply in the cervical mucus and vaginal fluid four to five days before the ovulation time, estimated by the LH peak, and rose again one to two days after ovulation. Anovulatory cycles did not show the midcycle drop in guaiacol peroxidase. Growth curve analysis gave excellent fitting of the guaiacol peroxidase data to a polynominal model. These data suggest that cervicovaginal guaiacol peroxidase may be clinically useful in detecting the fertile period for population control and for infertility treatment.

In vitro binding of insulin and epidermal growth factor to human endometrium and endocervix.

The distribution of receptors for insulin and epidermal growth factor along the longitudinal axis of the uterine cavity was studied in 28 uteri obtained from women of reproductive age undergoing hysterectomy for benign conditions. Insulin binding to crude plasma membranes was higher (p less than 0.05) in the secretory than in the proliferative phase of the menstrual cycle in all uterine segments (fundus to cervix). Epidermal growth factor binding did not change during the menstrual cycle but the number of epidermal growth factor binding sites was higher in the cervix than in the fundus (p less than 0.05). Scatchard plots of binding data, obtained with crude plasma membranes from pooled uteri, were curvilinear; the high-affinity sites had dissociation constants of 1 to 4 nmol/L and receptor concentrations of 100 to 300 fmol/mg of protein, for both iodine 125-labeled insulin and 125I-labeled epidermal growth factor. In plasma membranes, obtained from another 15 uteri, mouse nerve growth factor (3.3 micrograms/ml) decreased the binding of insulin by an average of 17% (p less than 0.005); in the decidua of a pregnant uterus at 12 weeks Scatchard analysis showed that nerve growth factor decreased the affinity but not the number of insulin-binding sites. Nerve growth factor had no effect on epidermal growth factor binding. Human prolactin (2 micrograms/ml) also decreased insulin binding by an average of 18% (n = 5, p less than 0.025) but had no effect on epidermal growth factor binding. These "baseline" data will be useful in further studies of the possible interactions between (1) receptors for various peptide growth factors and (2) sex steroid hormones, in normal and neoplastic endometrium and cervix.