THE INFLUENCE OF THE UTERUS ON THE CORPUS LUTEUM-PITUITARY RELATIONSHIP IN THE RAT

1963 ◽  
Vol 43 (4) ◽  
pp. 521-538 ◽  
Author(s):  
Martin Silbiger ◽  
Irving Rothchild
Keyword(s):  
Corpus Luteum ◽  
Compensatory Hypertrophy ◽  
Uterine Weight ◽  
Uterine Tissue ◽  
Late Afternoon ◽  
Mild Degree ◽  
Ovarian Compensatory Hypertrophy ◽  
Cervical Stimulation ◽  
Stimulation Of ◽  
Intact Rats

ABSTRACT The mechanism through which hysterectomy increases the duration of pseudopregnancy in the rat was studied. The operation resulted in a mean increase in dioestrous length of 8.8 days, and an incidence of such prolongations of about 78% when it was done before the late afternoon of the 9th dioestrous day; from this time until the 12th dioestrous day, the incidence of prolonged pseudopregnancies fell to 40%. Normal oestrous cycles were resumed following the pseudopregnant cycle, and cervical stimulation of such rats resulted in pseudopregnancies, of which 77% were prolonged. Sham operations involving only a mild degree of uterine trauma resulted in a 29% incidence of prolonged pseudopregnancies, while increase in the amount of uterine tissue removed (up to one entire horn) increased the incidence to 60%. The homotransplantation of a pituitary to pseudopregnant rats at the time of hysterectomy did not increase the incidence of prolonged pseudopregnancies in the first postoperative cycle, but did increase the degree of prolongation slightly. The cycles of hysterectomized rats bearing pituitary homotransplants – when compared with those of intact rats bearing such transplants – showed a 46% increase in the incidence of all pseudopregnant cycles; 10% of such cycles were prolonged in the intact rats, and 44% in the hysterectomized rats. Ovarian compensatory hypertrophy occurred at a slightly slower rate in cyclic hysterectomized rats than in rats with intact uteri; in pseudopregnant rats, hysterectomy delayed the onset of ovarian compensatory hypertrophy until after the 15th dioestrous day, while in rats with intact uteri, the increase in weight of the remaining ovary began on the 9th dioestrous day. The pituitary folliculotrophic potency (measured by mouse uterine weight increase) of pseudopregnant hysterectomized rats did not increase until the 15th day, while in pseudopregnant rats with intact uteri this increase was seen by the 7th day, and was of greater extent. These results were discussed in terms of whether hysterectomy increased LTH secretion, or decreased the secretion of a pituitary luteolytic factor, probably LH; it was suggested that the results could be more readily accounted for by the second possibility.

PITUITARY LACTOGENIC HORMONE RELEASE DURING ONSET OF PSEUDOPREGNANCY IN INTACT RATS

1965 ◽  
Vol 48 (2) ◽  
pp. 220-224 ◽  
Author(s):  
U. Herlyn ◽  
H.-F. Geller ◽  
Ilse v. Berswordt-Wallrabe ◽  
R. v. Berswordt-Wallrabe
Keyword(s):  
Hormone Release ◽  
Lactogenic Hormone ◽  
Pituitary Glands ◽  
Cervical Stimulation ◽  
Stimulation Of ◽  
Intact Rats

ABSTRACT The release of lactogenic hormone (LGH) was studied at the onset of pseudopregnancy in 90 rats. The LGH-content of the pituitary glands was determined by the pigeon crop sac assay. Glass rod stimulation of the cervix during vaginal oestrus was followed by a significant decrease in the LGH-content of the pituitary glands, thus demonstrating a correlation between LGH-release and beginning pseudopregnancy. Anaesthesia by Nembutal almost prevented this effect of cervical stimulation.

SOME OBSERVATIONS ON THE GONADOTROPHIN INHIBITING AND ANTI-PROGESTATIONAL PROPERTIES OF 20α-DIHYDROPROGESTERONE

1972 ◽  
Vol 71 (1) ◽  
pp. 13-23
Author(s):  
Anant P. Labhsetwar
Keyword(s):  
Synergistic Effect ◽  
Physiological Role ◽  
Biological Properties ◽  
Compensatory Hypertrophy ◽  
Oestrous Cycle ◽  
Simultaneous Administration ◽  
Pregnant Rats ◽  
Ovarian Compensatory Hypertrophy ◽  
Supporting Effect ◽  
Intact Rats

ABSTRACT 20α-dihydroprogesterone (20α-OH-P) was administered for 10 days either alone (2 or 4 mg/rat, sc) to explore its biological properties or in combination with progesterone (2 or 4 mg/rat, sc) to test its potential as an antiprogestin. When administered alone to intact rats the hydroxylated steroid, unlike progesterone, failed to disturb the oestrous cycle, cause ovarian or uterine atrophy, mucify the vagina or significantly modify pituitary stores of LH or FSH. In unilaterally spayed rats, 20α-OH-P proved ineffective in decreasing ovarian compensatory hypertrophy. Thus the loss of progestational properties in 20α-OH-P was associated with diminution in gonadotrophin-inhibiting properties. When administered to animals primed with oestrogen, 20α-OH-P exerted either an additive or synergistic effect on the trauma-induced deciduomata in bilaterally spayed rats and on the progestational proliferation in the immature rabbit. 20α-OH-P by itself had no significant effect under these conditions. In no instance did the hydroxylated steroid antagonize the effects of progesterone. In the pregnant rats bilaterally spayed and maintained on suboptimal doses of progesterone (1 mg/rat/day), simultaneous administration of 20α-OH-P (2 mg/day) did not antagonize the pregnancy supporting effect of progesterone. Thus under the conditions of these experiments 20α-OH-P failed to manifest any antiprogestin potential. It appears that 20α-OH-P may play a physiological role by potentiating or augmenting the effect of progesterone on decidualization.

Regulation of oxytocin secretion by the ovine corpus luteum: effect of activators of protein kinase C

1990 ◽  
Vol 124 (2) ◽  
pp. 225-232 ◽  
Author(s):  
J. J. Hirst ◽  
G. E. Rice ◽  
G. Jenkin ◽  
G. D. Thorburn
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Cyclic Amp ◽  
Corpus Luteum ◽  
Phospholipase C ◽  
Tissue Slices ◽  
Kinase C ◽  
Luteal Tissue ◽  
Dose Dependent ◽  
Stimulation Of

ABSTRACT The effect of protein kinase C activation and dibutyryl cyclic AMP on oxytocin secretion by ovine luteal tissue slices was investigated. Several putative regulators of luteal oxytocin secretion were also examined. Oxytocin was secreted by luteal tissue slices at a basal rate of 234·4 ± 32·8 pmol/g per h (n = 24) during 60-min incubations.Activators of protein kinase C: phorbol 12,13-dibutyrate (n = 8), phorbol 12-myristate,13-acetate (n = 4) and 1,2-didecanoylglycerol (n = 5), caused a dose-dependent stimulation of oxytocin secretion in the presence of a calcium ionophore (A23187; 0·2 μmol/l). Phospholipase C (PLC; 50–250 units/l) also caused a dose-dependent stimulation of oxytocin secretion by luteal slices. Phospholipase C-stimulated oxytocin secretion was potentiated by the addition of an inhibitor of diacylglycerol kinase (R59 022; n = 4). These data suggest that the activation of protein kinase C has a role in the stimulation of luteal oxytocin secretion. The results are also consistent with the involvement of protein kinase C in PLC-stimulated oxytocin secretion. The cyclic AMP second messenger system does not appear to be involved in the control of oxytocin secretion by the corpus luteum. Journal of Endocrinology (1990) 124, 225–232

AUGMENTATION BY CHLORMADINONE OF THE UTERINE WEIGHT RESPONSE TO HUMAN CHORIONIC GONADOTROPHIN IN INTACT IMMATURE RATS

1965 ◽  
Vol 33 (3) ◽  
pp. 447-454
Author(s):  
M. J. K. HARPER
Keyword(s):  
Single Injection ◽  
Direct Action ◽  
Follicular Development ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Female Rats ◽  
Uterine Weight ◽  
Control Value ◽  
Orally Active ◽  
Stimulation Of

SUMMARY Administration of chlormadinone, an orally active progestational agent without significant oestrogenic activity, to intact immature female rats did not affect either ovarian or uterine weight significantly compared with controls. A single injection of human chorionic gonadotrophin (HCG) caused a 73 % increase in uterine weight in 24 hr. over the control value. This dose significantly increased ovarian weight and although it caused some stimulation of follicular development, ovulation during this time did not occur. When animals were treated with chlormadinone for 8 days, and received HCG on the 8th day, uterine weight was 170% greater than in the controls and 56% greater than with HCG alone. The uterine weight produced was similar to that found in animals treated with mestranol, a potent oestrogen, and HCG. In ovariectomized animals HCG did not affect uterine weight, while the small increase produced by chlormadinone was unaltered when HCG also was given. Mechanisms are discussed by which this augmentation of the uterine response to HCG might be produced. It seems most likely that chlormadinone administration causes storage of endogenous gonadotrophin in the pituitary, and that the exogenous gonadotrophin acts as the 'trigger' for the release of stored hormone, probably by a direct action on the hypothalamus.

scholarly journals Reproductive Regulation and Oxidative Stress Alleviation of Chinese Herbal Medicine Therapy in Ovariectomised Mouse Model

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Chung-Hsin Wu ◽  
Sheue-Er Wang ◽  
Chih-Hsiang Hsu ◽  
Yu-Tsen Hsu ◽  
Chen-Wen Lu ◽  
...  
Keyword(s):  
Estrogen Receptor ◽  
Endometrial Thickness ◽  
Oral Treatment ◽  
Herbal Formula ◽  
Uterine Weight ◽  
Wild Type ◽  
Uterine Tissue ◽  
Sham Treatment ◽  
Reproductive Regulation ◽  
Calcium Phosphorus

In Taiwan, the herbal formula B401 is considered as a health supplement for middle-aged women that can alleviate sweating, anxiety, and sleep disorders. However, the relevant mechanisms are still unclear. In this study, we evaluated the beneficial effects of the herbal formula B401 therapy in the reproductive regulation of ovariectomised mice. Female ICR mice were randomised into four groups: wild-type (WT) mice with sham treatment, wild-type mice treated with the herbal formula B401, bilateral ovariectomised (OVX) mice with sham treatment, and bilateral ovariectomised mice treated with the herbal formula B401. Mice were orally given the herbal formula B401 at a dose of 30 mg/kg bw/day for 2 weeks. At the end of oral treatment with sham or the herbal formula B401, levels of reactive oxygen species (ROS), calcium, phosphorus, and estradiol-17βin the blood; uterine weight and endometrial thickness; and expressions of estrogen receptorα(ERα), estrogen receptorβ(ERβ), progesterone receptor (PR), vascular endothelial growth factor (VEGF), and superoxide dismutase 2 (SOD2) in the uterine tissue were examined and then compared among the four groups of mice. We found that OVX mice decreased levels of calcium, phosphorus, and estradiol-17βin the blood, decreased uterine weight and endometrial thickness, and decreased expressions of ERα, ERβ, PR, and SOD2 in the uterine tissue but increased blood ROS levels compared with those of WT mice. In addition, OVX mice with the herbal formula B401 therapy can increase levels of calcium, phosphorus, and estradiol-17βin the blood, increase uterine weight and endometrial thickness, and increase expressions of ERα, ERβ, PR, VEGF, and SOD2 in the uterine tissue but decrease blood ROS levels. Our results may provide reasonable explanation for the reproductive regulation of the herbal formula B401 therapy.

Effects of oestradiol, the oestrous cycle and pregnancy on weight, metabolism and cytosol receptors in the uterus of the brush-tail possum (Trichosurus vulpecula)

1986 ◽  
Vol 108 (2) ◽  
pp. 201-210 ◽  
Author(s):  
J. D. Curlewis ◽  
G. M. Stone
Keyword(s):  
Protein Synthesis ◽  
Protein Content ◽  
Corpus Luteum ◽  
Metabolic Activity ◽  
Weight Ratio ◽  
Oestrous Cycle ◽  
Uterine Weight ◽  
In Vitro Protein Synthesis ◽  
Vitro Protein

ABSTRACT Uterine weight, RNA, DNA, protein content, in-vitro rate of protein synthesis, cytosol oestrogen and progesterone receptors were examined after administration of oestradiol to ovariectomized animals and on days 0, 5, 9 and 13 of the non-pregnant cycle and day 13 of pregnancy. In ovariectomized animals, oestradiol increased uterine weight, RNA: DNA and protein: DNA ratios and the concentration of cytosol receptors for oestradiol and progesterone. During the oestrous cycle there was a linear increase in uterine weight and a significant effect of the corpus luteum on the weight of the ipsilateral uterus. Changes in RNA, DNA and protein content between days 0 and 5 were not observed, but between days 5 and 13 RNA: DNA and protein: DNA ratios increased and the DNA: tissue weight ratio decreased. Thus, cellular hypertrophy and/or increased metabolic activity rather than hyperplasia occur over this period, which is coincident with the known rise in plasma progesterone levels. The rate of in-vitro protein synthesis (per unit tissue protein) during the non-pregnant cycle was greatest at day 0. These changes in uterine metabolic activity were associated with alterations in cytosol receptor concentrations for both steroids. Cytosol progesterone receptor concentrations were highest at day 0 after which they declined to a minimum at day 13. Cytosol oestradiol receptor concentrations, however, rose between days 0 and 5 and then declined. Although lutectomy on day 8 of the cycle does not interfere with the development of a histologically normal luteal phase, high peripheral progesterone levels which occur after day 8 in intact animals are associated with major increases in uterine metabolic activity. The unilateral effect of the corpus luteum on uterine weight was associated with a decrease in DNA: g tissue ratio and an increase in rate of in-vitro protein synthesis indicating hypertrophy and/or extracellular accumulation of secreted material as well as enhanced metabolic activity. There was a significant effect of pregnancy on uterine weight at day 13 and this was associated with an increase in DNA content of both uteri. There was a unilateral effect of pregnancy on RNA: DNA ratio and in-vitro rate of protein synthesis, but not on uterine weight. J. Endocr. (1986) 108, 201–210

Comparison of bovine uterine horns for progesterone and oxytocin levels with bilateral corpus luteum

1996 ◽  
Vol 76 (3) ◽  
pp. 463-464 ◽  
Author(s):  
W. A. Cerbito ◽  
M. P. B. Wijayagunawardane ◽  
M. Takagi ◽  
K. Sato ◽  
A. Miyamoto ◽  
...  
Keyword(s):  
Key Words ◽  
Corpus Luteum ◽  
Estrous Cycle ◽  
Luteal Phase ◽  
Uterine Horn ◽  
Corpora Lutea ◽  
Uterine Tissue ◽  
Tissue Samples ◽  
Significant Difference ◽  
The Right

Bovine uterine horns with both ovaries containing a corpus luteum (CL) were compared for progesterone (P4) and oxytocin (OT) concentrations during the luteal phase of the estrous cycle. Uterine tissue samples from five Holstein cows with bilateral CL obtained from the slaughterhouse were used for this study. No significant difference was observed in P4 and OT levels in the right and left horns with corpora lutea in both ovaries. The data clearly indicate that both sides of the uterine horn having a functional CL are exposed to similar levels of P4 and OT, supporting the hypothesis that luteal products are delivered locally to the uterus. Key words: Progesterone, oxytocin, uterine horn, bilateral, corpus luteum, cow

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