Jessamine Hilliard

Effects of Intraventricular Infusions of Norepinephrine and Dopamine on LH Release and Ovulation in the Rabbit

The infusion of 50 µ g norepinephrine (NE) into the third ventricle of the brain was found to be highly effective in stimulating the release of an ovulatory surge of LH from the pitu

Plasma testosterone, estradiol, and gonadotrophins in hepatic insufficiency.

The pituitary- gonadal axis was evaluated in 22 male patients with hepatic insufficiency, utilizing measurements of serum estradiol, testosterone (T), follicle-stimulating hormone, and luteinizing hormone. In these patients, only levels of T were significantly different from those obtained in normal men (3.9 ng per ml in patients versus 5.2 ng per ml in normal subjects, P

Effects of luteinizing hormone-releasing hormone on fetal survival in pregnant rabbits.

The effect of synthetic luteinizing hormone-releasing hormone (LH-RH) on ovulation, implantation, and fetal survival rate was tested in pregnant rabbits. Single doses ranging from 2 to 900 mug, injected intravenously on the 3rd, 5th, or 6th postmating day, did not prevent implantation. Following the intravenous infusion of 20 to 200 mug of LH-RH on day 10 of pregnancy, the fetal survival rate was comparable to that of control rabbits laparotomized at the same stage of pregnancy. However, after repeated doses of 100 mug of LH-RH injected subcutaneously in a delaying vehicle either once or twice daily between the 8th and 13th days of gestation, multiple ovulations and severe luteolysis of original corpora lutea occurred, and fetal survival to term was highly variable. The results suggest that, depending on the dosage administered, LH-RH may either interrupt pregnancy by luteolysis or support fetal survival by stimulating luteotropic activity.

Stimulation of Progestin Release from Rabbit Ovary in vivo.

Summary 1) Progesterone and its metabolite Δ4-3-ketopregnene-20 a-ol are present in the ovarian vein blood of estrous rabbits without functional corpora lutea. 2) After mating or administration of a gonadotropin which induces ovulation, the output of these steroids is immediately elevated. 3) Gonadotropins, but not lactogenic hormone (LGH), also activate progestin release from the ovary containing functional corpora lutea of pregnancy or pseudopregnancy.

Serum Progesterone Levels in Hysterectomized Pseudopregnant Rabbits

Summary The effect of hysterectomy on luteal function was evaluated in 12 pseudo-pregnant rabbits by radioimmunoassay of progesterone in peripheral serum. Blood for assays was obtained by heart puncture before mating and on every third day of pseudo-pregnancy thereafter. Between Days 12 and 15, serum progesterone levels of the five controls fell sharply (M ± SE = 3.7 ± 1.0 ng/ml), whereas those of the seven hysterectomized animals remained higher (M ± SE = 10.1 ± 2.6 ng/ml). These findings are compatible either with a uterine luteolysin in the rabbit or with an “estrogen-sparing” effect of hysterectomy. The authors are indebted to Dr. Guy E. Abraham for the progesterone antiserum (S-41-6) used in the radioimmunoassays.

Circulating levels of pituitary gonadotrophins and ovarian steroids in rats after hypothalamic deafferentation.

Serum concentrations of LH, FSH, prolactin, estradiol, and progesterone were determined in female rats throughout the estrous cycle, ovariectomized rats, male rats, and female rats after surgical inte

Proteolytic Enzyme Inhibitors of Human Serum in Health and Disease.

Summary Methods are described for the determination of chymotrypsin and rennin inhibitors in serum. The many physiological and pathological conditions which influence their concentration are discussed.

Effect of Coitus on Serum levels of Testosterone and LH in Male and Female Rabbits

Summary Levels of testosterone (T) and LH in the peripheral serum of male and female rabbits were measured and compared following coitus. Blood was collected by heart puncture from restrained, unanesthetized animals of both sexes. In male rabbits, basal serum T levels were highly variable, ranging from 131 to 12,149 pg/ml, and if low preceding coitus they tended to rise; whereas, if high, they usually dropped as they did in nonmated males subjected to repeated heart punctures. In contrast, basal serum LH levels in males were quite constant (mean ± SE, 1993 ± 152 pg/ml) and were not significantly altered after coitus unless blood T levels had been drastically lowered by two priming doses of estradiol benzoate. In intact does, on the other hand, copulation which resulted in ovulation induced an approximately 20-fold increase in serum LH concentration which was sustained for about 4 hr. Postcoital elevations in serum LH also occurred in estrogen-primed intact and estrogen-primed ovariectomized does. Under the conditions of our experiments, the parallel elevations in serum LH and T observed postcoitally in the female rabbit could not be demonstrated in the male.

Preovulatory and postovulatory progestins in monkey ovary and ovarian vein blood.

Summary 1) Progesterone, 17 α-hydroxy-progesterone and 20 α-hydroxy-pregn-4-en-3-one were measurable in ovarian plasma or ovarian tissue following gonadotropic stimulation in 2 members of the Genus Lyssodes, M. mulatta and M. irus. 2) The presence of these progestins was not dependent upon the occurrence of ruptured follicles or recently formed corpora lutea. 3) Shortly after intravenous administration of human chorionic gonadotropin, the synthesis and release of these steroids were measurably increased.

Serum estradiol and progesterone concentrations in ovariectomized estrogen- and progesterone-primed and PMS-hCG-treated rats.

Summary Estradiol (E2) and progesterone (P) were measured by radioimmunoassay in peripheral blood serum on the second day of diestrus (D–2) and estrus (E) in normal cycling rats, in ovariectomized (OVX) animals, and in PMS–hCG– and OVX–E2–P–treated rats. PMS–hCG and OVX–E2–P animals had significantly higher estradiol and progesterone levels than cycling rats on D–2 or E. Progesterone was significantly higher in the PMS–hCG group while estradiol was higher in OVX–E2–P–treated rats. These results may provide an explanation of previous findings relative to LH dynamics in OVX–E2–P– and PMS–hCG–treated animals. We thank Mrs. Ruth Penardi, Miss Katherine Bangs, and Mrs. Frances Smith for technical and secretarial help and Mr. Bobby McAlister for drawing the figure.