SEXUAL PRECOCITY ASSOCIATED WITH THE CONCENTRATION OF PLASMA PROGESTERONE IN NELORE HEIFERS RAISED IN NORTHERN BRAZIL

ABSTRACT Progesterone was determined and identified in human peripheral blood during the preovulatory period of the menstrual cycle, by combined isotope derivative and recrystallization analysis. The mean concentration of progesterone in 1.095 ml of plasma obtained 9 days before ovulation was 0.084 μg/100 ml. However, the mean concentration of progesterone in 1.122 ml of plasma obtained 4 days before ovulation was 0.279 μg/100 ml. These data demonstrate a source of progesterone secretion other than the corpus luteum. The higher plasma-progesterone concentration 4 days before ovulation may indicate progesterone secretion of the ripening Graafian follicle of the ovary.

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HYPOTHALAMIC SEXUAL PRECOCITY IN FEMALE RATS OPERATED SHORTLY AFTER BIRTH

Acta Endocrinologica ◽

10.1530/acta.0.0410301 ◽

1962 ◽

Vol 41 (2) ◽

pp. 301-313 ◽

Cited By ~ 11

Author(s):

S. Horowitz ◽

J. J. Van der Werff ten Bosch

Keyword(s):

Anterior Commissure ◽

Anterior Hypothalamus ◽

Female Rats ◽

Vaginal Opening ◽

Sexual Precocity ◽

Paraventricular Nuclei ◽

Gonadotrophin Secretion ◽

Electrolytic Lesions

ABSTRACT Electrolytic lesions were placed in the anterior hypothalamus of 3–4 day-old female rats; vaginal opening was hastened in comparison with blank-operated littermates in 12 of 17 rats bearing a lesion in the basal supra-and post-chiasmatic area. In the animals with the earliest vaginal opening, lesions reached upward towards the region of the anterior commissure and the paraventricular nuclei. The degree of advancement of puberty in rats operated at the age of 3 or 4 days was similar to that caused by lesions made at 10, 14 or 15 days. This finding suggests that the effect of a lesion upon gonadotrophin secretion does not begin to take place until after the age of at least two weeks.

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PERIOVULATORY LEVELS OF PLASMA PROGESTERONE AND LUTEINIZING HORMONE IN WOMEN

Acta Endocrinologica ◽

10.1530/acta.0.061s214 ◽

1969 ◽

Vol 61 (1_Suppl) ◽

pp. S214 ◽

Cited By ~ 1

Author(s):

Elof Johansson ◽

Leif Wide

Keyword(s):

Luteinizing Hormone ◽

Plasma Progesterone

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AN IMPROVED METHOD FOR THE ASSAY OF PROGESTERONE BY COMPETITIVE PROTEIN BINDING

Acta Endocrinologica ◽

10.1530/acta.0.0630225 ◽

1970 ◽

Vol 63 (2) ◽

pp. 225-241 ◽

Cited By ~ 12

Author(s):

B. D. Reeves ◽

M. L. A. de Souza ◽

I. E. Thompson ◽

E. Diczfalusy

Keyword(s):

Protein Binding ◽

Binding Sites ◽

Entire Range ◽

Improved Method ◽

Plasma Progesterone ◽

Extraction And Purification ◽

Corticosteroid Binding Globulin ◽

Competitive Protein Binding ◽

The Individual ◽

Range Of Values

ABSTRACT An improved method for the assay of plasma progesterone by competitive protein binding is described. The improvement is based upon rigorous control of the variables, the compensation for and standardisation of interfering factors inherent in the method and the use of a human corticosteroid binding globulin, that meets the requirements for sensitivity at levels of 1.0 ng of progesterone and below. The assessment of the reliability of the individual steps in the method as well as that of the complete method is presented. The sensitivity of the method is around 0.2 ng progesterone per ml plasma. Accuracy was measured by adding progesterone in amounts ranging from 0.0 to 1.0 ng to 1.0 ml plasma. There was a linear relationship between the progesterone added and recovered throughout the entire range of values, with a coefficient of correlation (r) of 0.94. Of 52 related steroids tested, none was found which would remain associated with progesterone following extraction and purification and which would also compete with progesterone for binding sites.

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PROPRANOLOL-BLOCKADE OF VASOPRESSIN INDUCED INCREASE IN PLASMA PROGESTERONE IN EARLY HUMAN PREGNANCY

Acta Endocrinologica ◽

10.1530/acta.0.0660283 ◽

1971 ◽

Vol 66 (2) ◽

pp. 283-288 ◽

Cited By ~ 4

Author(s):

Petter Fylling

Keyword(s):

Cyclic Amp ◽

Uterine Cervix ◽

Adenosine Monophosphate ◽

First Trimester ◽

Blocking Agent ◽

Simultaneous Administration ◽

Plasma Progesterone ◽

Human Pregnancy ◽

Peripheral Plasma ◽

Early Human

ABSTRACT Following continuous dilation of the uterine cervix or intravenous infusion of vasopressin during the first trimester of human pregnancy, a marked increase in the peripheral plasma progesterone levels was observed. This effect was blocked by simultaneous administration of propranolol (Inderal®), a β-blocking agent. It is suggested that both these stimulating and inhibiting effects might be related to 3′, 5′-adenosine monophosphate (cyclic AMP). The results indicate the existence of β-receptors in steroid producing tissues.

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