Treatment With Estradiol (treatment + with_estradiol)

Distribution by Scientific Domains


Selected Abstracts


Maintenance of pregnancy in ovariectomized Mongolian gerbils (Meriones unguiculatus)

ANIMAL SCIENCE JOURNAL, Issue 5 2002
Osamu KAI
ABSTRACT Bilateral ovariectomy (Ovx) was carried out on day 20 of pregnancy in Mongolian gerbils (Meriones unguiculatus). The body weights of all groups tended to decrease on the day after the operation, and the decrease was significant in the group that was ovariectomized and given vehicle (Ovx + vehicle group). The body weight in this group never recovered until autopsy on day 24, which is normally 1 day before parturition. No fetuses survived to the time of autopsy in any of the animals of the Ovx + vehicle group. Daily administration of 4 mg of progesterone (P4) prevented the termination of pregnancy in Ovx animals, but 1 mg did not. Treatment with estradiol 17, (E2) in addition to 4 mg of P4 tended to result in a lower rate of fetal survival than that of the Ovx group treated with 4 mg of P4 alone. With regard to fetal weight, treatment with 4 mg of P4 resulted in the same weight as in the sham-operated controls, but the addition of 0.2 or 1 ,g of E2 to the 4 mg of P4 resulted in a significantly lower weight than that of fetuses in the 4 mg of P4 group. The present study suggests that adequate maintenance of pregnancy in ovariectomized gerbils can be achieved by daily treatment with 4 mg of P4 alone. Moreover, treatment with 0.2 or 1 ,g of E2 in addition to 4 mg of P4 caused a deterioration in the maintenance of gestation, in contrast to the effects in rats, mice and hamsters. [source]


Protection of estrogens against the progression of chronic liver disease

HEPATOLOGY RESEARCH, Issue 4 2007
Ichiro Shimizu
Hepatitis C virus infections are recognized as a major causative factor of chronic liver disease. A characteristic feature of chronic hepatitis C, alcoholic liver disease and non-alcoholic fatty liver disease is hepatic steatosis. Hepatic steatosis leads to an increase in lipid peroxidation in hepatocytes, which, in turn, activates hepatic stellate cells (HSCs). HSCs are also thought to be the primary target cells for inflammatory and oxidative stimuli, and to produce extracellular matrix components. Based on available clinical information, chronic hepatitis C appears to progress more rapidly in men than in women, and cirrhosis is predominately a disease of men and postmenopausal women. Estradiol is a potent endogenous antioxidant. Hepatic steatosis was reported to become evident in an aromatase-deficient mouse and was diminished in animals after treatment with estradiol. Our previous studies showed that estradiol suppressed hepatic fibrosis in animal models, and attenuated HSC activation by suppressing the generation of reactive oxygen species in primary cultures. Variant estrogen receptors were found to be expressed to a greater extent in male patients with chronic liver disease than in female subjects. A better understanding of the basic mechanisms underlying the gender-associated differences observed in the progression of chronic liver disease would provide valuable information relative to the search for effective antifibrogenic therapies. [source]


Remodeling of extracellular matrix at ovulation of the bovine ovarian follicle

MOLECULAR REPRODUCTION & DEVELOPMENT, Issue 10 2006
H.F. Irving-Rodgers
Abstract Using immunohistochemistry and RNA analyses we examined the fate of components of a newly identified matrix that develops between granulosa cells (focimatrix, abbreviated from focal intraepithelial matrix) and of the follicular basal lamina in ovulating bovine ovarian follicles. Pre- and postovulatory follicles were generated by treatment with estradiol (Day 1), progesterone (Days 1,10), and prostaglandin analogue (Day 9) with either no further treatment (Group 1, n,=,6) and or with 25 mg porcine LH (Day 11, Group 2, n,=,8 or Day 10, Group 3, n,=,8) and ovariectomy on Day 12 (12,14 hr post LH in Group 2, 38,40.5 hr in Group 3). In the time frame examined no loss of follicular basal lamina laminin chains ,2 and ,1 or nidogen 1 was observed. In the follicular basal lamina collagen type IV ,1 and perlecan were present prior to ovulation; after ovulation collagen type IV ,1 was discontinuously distributed and perlecan was absent. Versican in the theca interna adjacent to the follicular basal lamina in preovulatory follicles was not observed post ovulation, however, the granulosa cells then showed strong cytoplasmic staining for versican. Expression of versican isoforms V0, V1, and V3 was detected at all stages. Focimatrix was observed in preovulatory follicles. It contained collagen type IV ,1, laminins ,2 and ,1, nidogen 1 and perlecan and underwent changes in composition similar to that of the follicular basal lamina. In conclusion focimatrix and the follicular basal lamina are degraded at ovulation. Individual components are lost at different times. Mol. Reprod. Dev. © 2006 Wiley-Liss, Inc. [source]


Inhibition of aggression by progesterone and its metabolites in female Syrian hamsters

AGGRESSIVE BEHAVIOR, Issue 5 2001
Jess G. Kohlert
Abstract The sequence of estradiol and progesterone is known to inhibit the expression of aggression in female hamsters. Despite the key importance of progesterone in the inhibition of aggression, little is known of the mechanisms through which progesterone may exert this effect. Three experiments were performed to assess the degree to which metabolites of progesterone can affect aggression in female Syrian hamsters. Systemic estradiol treatment followed by injections of either progesterone (300 ,g IP) or 4-pregnen-21-ol-3,20-dione (DOC, 300 ,g IP) reliably inhibited aggression. Systemic injection (75, 150, or 300 ,g IP) of either 5,-pregnan-3,,21-diol-20-one (THDOC) or 5,-pregnan-3,-ol-20-one (3,,5,-THP) did not affect aggression. Intracerebroventricular infusion of 3,,5,-THP following systemic estradiol treatment also did not affect aggression. In a third experiment, female hamsters were given systemic treatments with estradiol and progesterone that were subthreshold with respect to inhibition of aggression. In these females, intracerebroventricular infusion of THDOC inhibited aggression. These results indicate that metabolites of progesterone can inhibit aggression, most notably in synergy with progesterone itself. Aggr. Behav. 27:372,381, 2001. © 2001 Wiley-Liss, Inc. [source]