Comparison of the Long-Term Effects of Estrogen and Clomiphene Citrate on Pituitary and Uterine Function in Ovariectomized Rats

1991 ◽  
Vol 31 (1) ◽  
pp. 23-29 ◽  
Author(s):  
Janine Brown ◽  
Sharon J. Byrd ◽  
Annette Mitchell ◽  
Myra F. Nelson ◽  
Ronald L. Young ◽  
...  
Keyword(s):  
Clomiphene Citrate ◽  
Ovariectomized Rats ◽  
Long Term Effects ◽  
Uterine Function

ALTERATIONS INDUCED BY CLOMIPHENE IN THE CONCENTRATIONS OF OESTROGEN RECEPTORS IN THE UTERUS, PITUITARY GLAND AND HYPOTHALAMUS OF FEMALE RATS

1980 ◽  
Vol 87 (3) ◽  
pp. 383-392 ◽  
Author(s):  
E. Y. ADASHI ◽  
A. J. W. HSUEH ◽  
S. S. C. YEN
Keyword(s):  
Pituitary Gland ◽  
Nuclear Receptors ◽  
Single Injection ◽  
Clomiphene Citrate ◽  
Female Rats ◽  
Ovariectomized Rats ◽  
Oestrogen Receptors ◽  
Prolonged Retention

Alterations in the concentrations of oestrogen receptors in the uterus, pituitary gland and hypothalamus during the 2 weeks following a single administration of clomiphene citrate (Clomid) to immature, bilaterally ovariectomized rats were investigated. Examination of the uterine wet weight at 1, 7 and 14 days following a single injection of Clomid (100 μg, 250 μg or 10 mg) indicated significant time- and dose-related increments from a control value of 45 ± 2 (s.e.m.) mg to a maximum of 123 ± 3 mg (250 μg dose at 14 days). In contrast, a single injection of oestradiol led to a transient increase in the uterine weight on day 1 to 94 ± 6 mg, but was without effect by days 7 and 14. Analysis of the uterine DNA content 7 and 14 days after treatment with Clomid revealed significant increments from control values of 390 ± 10 μg to a high level of 558 ± 8 μg (10 mg dose at 7 days). There was a transient retention of nuclear oestrogen receptors and rapid replenishment of cytoplasmic oestrogen receptors in less than 24 h in the uteri of animals treated with oestradiol (25 μg), but determinations of receptor content in Clomid-treated animals revealed prolonged retention of nuclear receptors and delayed replenishment of cytoplasmic receptors. The duration and extent of retention of nuclear receptors and depletion of cytoplasmic receptors after treatment with Clomid were found to be dose-dependent. Fourteen days after Clomid treatment, levels of oestrogen receptors in nuclei from the uterus were still raised in all treatment groups, whereas replenishment of cytoplasmic receptors was complete in animals treated with the lower doses (100 and 250 μg) of Clomid. A single injection of Clomid (250 μg) induced similar prolonged retention of nuclear receptors and delayed depletion of cytoplasmic receptors in pituitary tissue. In contrast, changes in the content of oestrogen receptors in the hypothalamus following Clomid treatment were minimal. The limited effect of Clomid on hypothalamic tissue may mean that the pituitary gland is a more important target for this compound than is the hypothalamus. The findings have confirmed earlier reports on the long-term uterotrophic effect of Clomid and have suggested that under these long-term, in-vivo conditions, Clomid acts in the uterus and pituitary gland as a long-acting oestrogen characterized by prolonged retention of oestrogen receptors in the nucleus and delayed, but otherwise effective, replenishment of the oestrogen receptors in the cytoplasm.

A possible role of clomiphene citrate in the control of pre-ovulatory LH surge during induction of ovulation

1985 ◽  
Vol 109 (1) ◽  
pp. 58-63 ◽  
Author(s):  
Naoki Terakawa ◽  
Ikuya Shimizu ◽  
Hirohisa Tsutsumi ◽  
Toshihiro Aono ◽  
Keishi Matsumoto
Keyword(s):  
Nuclear Receptor ◽  
Clomiphene Citrate ◽  
Ovariectomized Rats ◽  
Receptor Complex ◽  
Oestrogen Receptors ◽  
Lh Surge ◽  
Serum Lh ◽  
Lh Release

Abstract. A possible role of clomiphene citrate (clomiphene) in the control of ovulation in anovulatory women was investigated. Since a single ip administration of 5 μg oestradiol-17β (E2) to long-term ovariectomized rats did not induce LH surge, the following studies were designed to determine whether pretreatment with clomiphene followed by administration of E2 could induce LH surge in the ovariectomized rats. Changes in cytoplasmic and nuclear oestrogen receptors (ER) were also examined in the pituitaries of these animals. An ip injection of 200 μg clomiphene suppressed serum LH levels significantly for 72 h. The clomiphene injection rapidly caused an elevation of nuclear ER with a concomitant depletion of cytoplasmic ER level in the pituitary and the ER levels remained almost unchaged for 72 h. An administration of E2 12 or 24 h after the clomiphene injection had no significant effects on either the serum LH levels or the cytoplasmic and nuclear ER levels, compared with those induced by clomiphene alone. However, LH surge and the depletion of nuclear ER in the pituitary occurred 24 h later when E2 was injected 48 h after the clomiphene administration. The E2-induced LH release seems to be induced by a replacement of clomiphene by E2 on the nuclear receptor complex. These results suggest that clomiphene may exert actions directly on the pituitary gland to augment oestrogeninduced LH release.

Long-term effects of the rhapontic rhubarb extract ERr 731® on estrogen-regulated targets in the uterus and on the bone in ovariectomized rats

2012 ◽  
Vol 128 (1-2) ◽  
pp. 62-68 ◽  
Author(s):  
Annekathrin Martina Keiler ◽  
Anja Papke ◽  
Georg Kretzschmar ◽  
Oliver Zierau ◽  
Günter Vollmer
Keyword(s):  
Ovariectomized Rats ◽  
Long Term Effects

Short- and Long-Term Effects of Clomiphene Citrate on the Pituitary-Testicular Axis

1971 ◽  
Vol 33 (6) ◽  
pp. 970-979 ◽  
Author(s):  
R. J. SANTEN ◽  
J. M. LEONARD ◽  
R. J. SHERINS ◽  
H. M. GANDY ◽  
C. A. PAULSEN
Keyword(s):  
Clomiphene Citrate ◽  
Long Term Effects ◽  
Short And Long Term

scholarly journals Long-term effects of alendronate on fracture healing and bone remodeling of femoral shaft in ovariectomized rats

2013 ◽  
Vol 34 (3) ◽  
pp. 387-392 ◽  
Author(s):  
Ling-jie Fu ◽  
Ting-ting Tang ◽  
Yong-qiang Hao ◽  
Ke-rong Dai
Keyword(s):  
Fracture Healing ◽  
Bone Remodeling ◽  
Femoral Shaft ◽  
Ovariectomized Rats ◽  
Long Term Effects

Short-term and long-term effects of osteoporosis on incisor teeth and femoral bones evaluated by Raman spectroscopy and energy dispersive X-ray analysis in ovariectomized rats

2018 ◽  
Vol 37 (1) ◽  
pp. 18-27 ◽  
Author(s):  
Fernanda Rossi Paolillo ◽  
Renan Arnon Romano ◽  
Luciana de Matos ◽  
Airton Abrahão Martin ◽  
Francisco Eduardo Gontijo Guimarães ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Energy Dispersive ◽  
Ovariectomized Rats ◽  
Long Term Effects ◽  
Short Term ◽  
X Ray

Ovarian Dysfunction in Fetally Irradiated Beagles

1977 ◽  
Vol 35 ◽  
pp. 658-659
Author(s):  
T. M. Seed ◽  
M. H. Sanderson ◽  
D. L. Gutzeit ◽  
T. E. Fritz ◽  
D. V. Tolle ◽  
...  
Keyword(s):  
Gamma Rays ◽  
Low Dose ◽  
Long Term Effects ◽  
Ovarian Dysfunction ◽  
Dose Rates ◽  
Highly Sensitive ◽  
Microscopic Evaluation ◽  
Ovarian Pathology ◽  
Normal Offspring

The developing mammalian fetus is thought to be highly sensitive to ionizing radiation. However, dose, dose-rate relationships are not well established, especially the long term effects of protracted, low-dose exposure. A previous report (1) has indicated that bred beagle bitches exposed to daily doses of 5 to 35 R 60Co gamma rays throughout gestation can produce viable, seemingly normal offspring. Puppies irradiated in utero are distinguishable from controls only by their smaller size, dental abnormalities, and, in adulthood, by their inability to bear young.We report here our preliminary microscopic evaluation of ovarian pathology in young pups continuously irradiated throughout gestation at daily (22 h/day) dose rates of either 0.4, 1.0, 2.5, or 5.0 R/day of gamma rays from an attenuated 60Co source. Pups from non-irradiated bitches served as controls. Experimental animals were evaluated clinically and hematologically (control + 5.0 R/day pups) at regular intervals.

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