The menopause
Michael J. O’Dowd in The History of Medications for Women, 2020
In a brief look at the hormonal therapy for the ‘change of life’ Wilson wrote that ‘Investigation of the therapeutic uses of estrogens followed close upon Doisy’s historic discovery of these hormones in 1923. Curiously, the initial research was carried out largely in agricultural colleges with a hopeful view towards encouraging the sex life of chickens’. Wilson’s own initial experiments, in the late 1920s, were carried out with a crude extract made from dried sheep ovaries. Estrogen became available in the early 1930s and the German preparation, estradiol benzoate, that was relatively side-effect free, allowed patients to enjoy the benefits of estrogen therapy without discomfort. Some clinicians nicknamed it the ‘cadillac of hormones’, but unfortunately the preparation had to be given on an on-going basis by intramuscular injections. Natural conjugated estrogens became available shortly after the outbreak of World War Two. They were prepared from mares’ urine and soon the conjugated estrogens became available in convenient tablet form.
Reproductive Neuroendocrine Effects of Neuropeptide Y and Related Peptides
Craig A. Johnston, Charles D. Barnes in Brain-Gut Peptides and Reproductive Function, 2020
Alterations in plasma levels of gonadal steroids also affect the concentration of NPY in the hypothalamus. Crowley et al. (1985) examined the effects of bilateral OVX followed by treatment with estrogen alone or the combination of estrogen and progesterone on NPY levels in several brain regions. Injection of 50 μg of estradiol benzoate significantly decreased NPY levels in the ME 48 h later. Injection of a single dose of progesterone (2.5 mg) at 10:00 AM into OVX and estrogen-treated animals induced a significant increase in NPY levels in the ME 1 h later followed by a gradual decline. The pattern of NPY alterations in the ME after progesterone administration was similar to that for LHRH. These changes in the levels of both peptides preceded the afternoon rise in plasma LH. A significant decline in NPY concentration was detected in the interstitial nucleus of the stria terminalis and in the arcuate nucleus following estrogen treatment, while no changes were observed in the preoptic, periventricular and ventromedial nuclei. Progesterone treatment further decreased NPY levels in the interstitial nucleus of the stria terminalis and in the ventromedial nucleus while transient declines were seen in the preoptic and arcuate nuclei (Crowley et al., 1985).
ExperimentaL Oral Medicine
Samuel Dreizen, Barnet M. Levy in Handbook of Experimental Stomatology, 2020
The effect of estrogens on the gingiva and alveolar bone of rats and mice was reported by Nutlay et al.22 In this study, 16 newborn rats were divided into eight controls and eight recipients of 0.05 to 1.30 mg a-estradiol benzoate by injection. All were sacrificed 5 to 42 days later. Of a group of newborn mice, 22 were segregated into eight controls; 6 were given 0.05 to 0.80 mg diethylstilbestrol by weekly injections and sacrificed at 5 to 30 days of age, and 8 were given a total of 0.05 to 1.30 mg α-estradiol benzoate and killed at 5 to 40 days of age. A group of 23 mice, 1 year of age, were distributed among six controls; 9 received a s.c. pellet of about 2 mg crystalline α-estradiol benzoate and sacrificed after 1 to 13 study weeks, and 8 were given a total of 1.5 to 6.0 mg α-estradiol benzoate in 0.50 mg weekly injections and terminated 3 to 12 weeks later.
Long-term reproductive effects of benzo(a)pyrene at environmentally relevant dose on juvenile female rats
Published in Drug and Chemical Toxicology, 2023
Ana Carolina Casali Reis, Bárbara Campos Jorge, Beatriz Rizzo Paschoalini, Jéssica Nogueira Bueno, Julia Stein, Suyane da Silva Moreira, Beatriz de Matos Manoel, Glaura Scantamburlo Alves Fernandes, Hamilton Hisano, Arielle Cristina Arena
To evaluate a possible estrogenic activity of BaP, immature female rats on PND 21 (Odum et al.1997, Arena et al.2008) received 0.1 µg/kg/day of BaP for 3 consecutive days, by oral gavage. The vehicle was administered as a negative control, while estradiol benzoate (β-Estradiol 3-Benzoate, Sigma; 0.4 mg/kg/day) was used as a positive control for estrogenicity (Figure 1). Twenty-four hours after the final dose, the females were weighted and anesthetized with sodium pentobarbital (40 mg/kg, i.p.). Uteri were excised, trimmed free of fat, pierced, and blotted to remove fluid. The body of the uterus was cut just above its junction with the cervix and the junction of the uterine horns with the ovaries (Odum et al.1997). Wet uterus weights were determined and expressed as relative weights (wet uterus weight/body weight × 100).
Pharmacodynamics of combined estrogen-progestin oral contraceptives 3. Inhibition of ovulation
Published in Expert Review of Clinical Pharmacology, 2018
Carlo Bastianelli, Manuela Farris, Elena Rosato, Ivo Brosens, Giuseppe Benagiano
The idea of blocking ovulation through the administration of estrogens is more than 80 years old: in 1937, Kurzrok [2] stressed that any hormonal contraceptive method acts by producing temporary sterility and that hormonal sterilization deals with methods that render the woman sterile for the duration of at least one menstrual cycle. He reported that in mice and rabbits, estrone has a depressant effect on ovarian response to FSH and that large doses of estradiol benzoate used to treat dysmenorrhea altered menstrual rhythm. A few years later, Sturgis and Albright [3] confirmed that ‘estrin’, when used to treat severe dysmenorrhea, blocked ovulation. In 1943, Lyon [64] proved that the daily administration of 50 µg EE was indeed capable of blocking ovulation, as determined by the presence of a monophasic basal body temperature recording. Initially, there was skepticism over the ability of estrogens to constantly inhibit fertility, because of what was coined at the time as ‘pituitary escape’, a concept criticized by Rudel et al. as unproven [24]. The same group presented data showing that MSN is able to inhibit ovulation at the daily dose of 80 µg, but failed to do so when given at the dose of 40 µg [65].
Stress and steroid interaction modulates expression of estrogen receptor alpha in the brain, pituitary, and testes of immature Gallus gallus domesticus
Published in Stress, 2021
Kalpana Baghel, Rashmi Srivastava
One-day old chicks were taken and reared for 2 months under laboratory conditions, then randomly assigned into four groups (n = 8 each). First group served as a control (C) in which 0.9% saline was administered intraperitoneally for 12 days, food and water was provided ad libitum. The second group was food restricted (FR) for 9 h/day from sixth day till the last day of experiment. The third and fourth groups were administered with estradiol benzoate (EB) (Sigma-Aldrich, St. Louis, MO) at a dose (0.5 mg/100g body weight/day) intraperitoneally for 12 days continuously. But, the fourth group was treated with EB followed by food restriction (EB + FR) of 9 h/day from sixth day till last day of experiment. After 12 days of experimental duration, the body weights of all birds were measured and blood samples were collected from the wing vein in a heparinized syringe. Plasma was isolated and kept in −20 °C for further hormonal analysis of corticosterone and estradiol. Four chicks from each group were anesthetized using sodium phenobarbital and perfused with 0.02 M phosphate-buffered saline (PBS) followed by Zamboni’s fixative through left ventricle of the heart. Brain, pituitary and testes were excised and post fixed in Zamboni’s fixative for 24–48 h for histology and immuno-fluorescent localization.
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- Estrogen
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