Plasma progesterone secretion by the corpus luteum of term pregnancy

LeMaire, William J.; Conly, Patricia W.; Moffett, Alfred; Cleveland, William W.

doi:10.1016/0002-9378(70)90217-6

Cited by 24 publications

(3 citation statements)

References 6 publications

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“…The apparently low level of the receptor is most likely due to occupation (11) and down-regulation of the receptors by high serum levels of hCG (29). The presence of the receptors in somewhat higher numbers at term may be associated with progesterone (30) and relaxin secretion (31). However, their functional relevance remains to be seen.…”

Section: Discussionmentioning

confidence: 99%

Luteinizing Hormone Receptors in Human Ovarian Follicles and Corpora Lutea during Menstrual Cycle and Pregnancy*

Rajaniemi

Rönnberg

Kauppila

et al. 1981

The Journal of Clinical Endocrinology & Metabolism

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Specific high affinity, low capacity binding of [ l25 I]iodo-hCG was demonstrated in homogenates of isolated granulosa cells and corpora lutea of human ovary throughout the menstrual cycle and pregnancy. The binding of radiolabeled hCG to the receptor was time, temperature, ion concentration, and pH dependent. The treatment of ovarian membrane particles with trypsin decreased binding by about 75%, whereas treatment and neuraminidase resulted in a 400% increase in binding. These results suggest a protein nature of the receptor and that a portion of the receptors may be masked in the membrane by sialic acid. The receptor displayed high specificity for hCG and human LH, indicating that they share the same receptor site in the human ovary. The receptor bound hCG with high affinity. The apparent equilibrium association constant for hCG was 2.2 X 10 9 M~\ The receptor concentration increased from the early follicular phase to ovulation by about 1.6-fold. After an apparent transient fall associated with the ovulatory period, the receptor concentration increased further by about 4-fold by day 17 of the cycle and thereafter remained virutally unchanged until the end of the cycle. Homogenates of corpora lutea obtained during the follicuar phase aso bound specifically radiolabeled hCG, suggesting that the regression of the corpora lutea is not primarily due to the loss of receptors for human LH. The receptor concentration measured in corpora lutea of early pregnancy was clearly lower than that in corpora lutea of the menstrual cycle. This is most likely due to occupation and downregulation of the receptors by high serum hCG. The number of receptors in corpora lutea tended to increase towards the end of pregnancy.Our results indicate that the maturation and subsequent luteinization of human ovarian follicles is associated with a biphasis increase in the number of LH (hCG) receptors in granulosa cells. The changes in the concentration of available receptor may have a determining role in the regulation of follicular and corpus luteum development and function. (J Clin Endocrinol Metab 108: 307, 1981) H UMAN LH (hLH) and hCG appear to be the major luteotropic factors for the human corpus luteum during the menstrual cycle and pregnancy (1-4). Specific stimulation of steroidogenesis in human corpora lutea by hLH and hCG has been demonstrated in vitro (1, 2, 5). In addition, the administration of hCG in vivo during the early luteal phase prolongs the lifespan and function of the corpus luteum to a certain extent, but not beyond 9 days (3, 4). Other data have shown that hLH can also extend the lifespan of the corpus luteum of the menstrual cycle and increase the serum progesterone concentration (3, 4). Fundamental to our understanding of regulation of follicular development and corpus luteum function is knowledge of the properties of the gonadotropin recep-

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Section: Discussionmentioning

confidence: 99%

Luteinizing Hormone Receptors in Human Ovarian Follicles and Corpora Lutea during Menstrual Cycle and Pregnancy*

Rajaniemi

Rönnberg

Kauppila

et al. 1981

The Journal of Clinical Endocrinology & Metabolism

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“…In several species progesterone is also involved in some aspects of maternal behavior, such as hair pulling, nest building, and mothering (Thau and Lanman, 1975). The progesterone concentration in maternal blood rises during pregnancy to values ranging from 11 to 32 mg/JOO ml of plasma, as compared with nonpregnancy levels, varying from 0.1 to 2 mg/lOO of plasma (Johansson, 1969;LeMaire et at., 1970).…”

Section: 42a Changes In Placentalmentioning

confidence: 97%

Nutrition and Pregnancy

Rosso

Cramoy

1979

Nutrition

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“…Plasma and tissue concentrations of hormones, especially oestrogens and progesterone, vary considerably during the menstrual cycle and during pregnancy 1–4 . In general, these substances are known to affect myometrial activity 5–8 .…”

Section: Introductionmentioning

confidence: 99%

Contraction kinetics of isolated human myometrium during menstrual cycle and pregnancy

Tchirikov¹,

Peiper²,

Schröder³

2000

BJOG

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Objective DesignSetting Eppendorf University Hospital, Hamburg. Samples MethodsTo investigate the interaction between actin and myosin in the myometrium by studying the contraction kinetics of isolated samples of human myometrium.Experimental and observational cross-sectional study.Myometrium samples were taken from women in the follicular phase (n = 6) or luteal phase (n = 6) of the menstrual cycle and during pregnancy at term (n = 25).The frequency, extent and rate of force development were determined in spontaneously active myometrial preparations. From a resting force of 2 mN, sustained tonic contractions were induced by K+-depolarisation (124 mM), or by protein kinase C activation (19.9 yM indolactam). The steady force was reversibly interrupted by rapid length changes (100 Hz sinus vibrations lasting 1 s, 5% of muscle length). Extent (steady plateau), as well as rate of force increase after cessation of vibrations, were derived from bi-exponential functions fitted to the time course of force recovery. Conclusions The responses of human myometrium to contraction stimuli differ according to the reproductive state. Membrane depolarisation causes similar responses in all myometrial strips. In contrast, near term stimulation of protein kinase C generates a large tonic force and slow contraction kinetics, whereas early in the menstrual cycle contraction kinetics are fast.[24.4 s (5-9); P < 0.0051.

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Plasma progesterone secretion by the corpus luteum of term pregnancy

Cited by 24 publications

References 6 publications

Luteinizing Hormone Receptors in Human Ovarian Follicles and Corpora Lutea during Menstrual Cycle and Pregnancy*

Luteinizing Hormone Receptors in Human Ovarian Follicles and Corpora Lutea during Menstrual Cycle and Pregnancy*

Nutrition and Pregnancy

Contraction kinetics of isolated human myometrium during menstrual cycle and pregnancy

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