Disease relevance of Hydroxyestrin benzoate

• Hemipituitary glands obtained from animals primed with a single dose of oestradiol benzoate (OB; 20 microgram/100 g body weight) released significantly more LH when pulsed with GnRH (4 nmol/1) than did control hemipituitary glands [1].
• Neither the amount nor the Spinnbarkeit of mucus varied with the dose of OB in ewes with permanent infertility caused by grazing oestrogenic pasture (clover-affected ewes) [2].
• When administered to ovariectomized females, primed with oestradiol benzoate (OB) and progesterone, alpha-MSH increased lordosis behaviour in those rats that showed a low level of receptivity but in rats that were receptive it had an inhibitory effect. alpha-Melanocyte stimulating hormone also inhibited proceptive behaviour in these females [3].
• A simultaneous LH and FSH surge was observed in the serum of half of the OeB-treated females killed by decapitation of dioestrus II at 17.30 [4].

High impact information on Hydroxyestrin benzoate

• However, a single progesterone injection (5 mg, sc) 24 h after EB had no significant effect on either cytoplasmic or nuclear estrogen receptor levels [5].
• Likewise, injection of defective viral vector into the hypothalamus followed by treatment with EB resulted in a approximately eightfold increase in cells demonstrating beta-galactosidase activity including the very cell groups responsible for EB-dependent reproductive behavior [6].
• A significant increase in serum PRL at 13:00 and 18:00 h was induced by OB treatment [7].
• To analyse the hypothalamus and/or pituitary involvement in this inhibition, pituitary responsiveness to acute stimulation with LH-releasing hormone (LHRH) was studied in vivo and in vitro in Wistar male rats injected on day 1 of age with oestradiol benzoate (OB) or olive oil [8].
• These data suggest that GnRH pulses are important in the generation of the OB-induced LH surge, but that a baseline secretory component can prime the pituitary to some extent [9].

Biological context of Hydroxyestrin benzoate

• Treatment with the same dose of OB at 60 days of rats injected with 10 microgram testosterone propionate on Day 4 of postnatal life resulted in an increased incidence of failure of ovulation at 120 though not at 150 days of age but did not further impair the already reduced gonadotrophin response to progesterone at 160-180 days of age [10].
• The effects of daily injections of oestradiol benzoate (OB) between days 9 and 11 of lactation, and/or grafting with three isologous anterior pituitary glands on day 1, on the growth of the litter and the development and function of mammary glands were studied on day 12 of lactation in C3H/He mice [11].
• On Day 18 OB injection (5 micrograms) advanced the mean time of parturition by 5-6 h (P less than 0.001) whereas injection on Days 19 or 20 delayed delivery by more than 6.5 and 8.5 h respectively (P less than 0.05) [12].
• The gonadotrophic response to a single injection of oestradiol benzoate (OB) was studied in acutely ovariectomized adult rats during the different stages of a 4-day ovarian cycle [13].
• It was concluded that i) OeB caused a synergistic release of LH and FSH ii) bleeding by cardiac puncture as such may constitute a source of inhibition of OeB-induced luteinization [4].

Anatomical context of Hydroxyestrin benzoate

• Thus, hemipituitary glands were obtained from animals given two injections of OB, an injection of pregnant mare serum gonadotrophin (PMSG) or a unilateral brain lesion placed in the basal hypothalamus [1].
• Ovariectomized ewes treated with oestradiol benzoate (OB) had a reduced cervical mucus response to subsequent treatment with OB [14].
• We have concluded that large doses of oestrogen significantly decrease oestrogen receptor content in the rat uterus, especially when OB is used [15].
• In-situ hybridization carried out with a 30 mer, 32P-labelled, oligonucleotide probe complementary to LHRH mRNA showed that the concentrations of LHRH mRNA in perikarya in the medial preoptic area, diagonal band and medial septum were significantly greater in OB-compared with oil-treated rats [16].
• At each interval of time and for each region of the cervix, fewer spermatozoa were recovered from the ewes treated with 30 mug OB than from those treated with 90 mug (P less than 0-05) [17].

Associations of Hydroxyestrin benzoate with other chemical compounds

• Furthermore, the increase in Spinnbarkeit of cervical mucus seen in normal ewes treated over a 3-day period with OB or with implants containing oestradiol did not occur in affected ewes [2].
• Removal of pups from lactating rats and subsequent maintenance of high prolactin levels by daily treatment with the dopamine receptor antagonist domperidone (2.5 mg/day) maintained the state of refractoriness to the behavioural effects of OB and progesterone provided that the ovaries remained in situ [18].
• Injection of 2.5 mg of the dopamine receptor antagonist domperidone raised serum prolactin concentrations within 3 h and high prolactin levels were maintained for 12 h in ovariectomized rats pretreated with 2 micrograms oestradiol benzoate (OB) [19].

Gene context of Hydroxyestrin benzoate

• The effect of chronic administration of a high dose of oestradiol benzoate (OB) on growth and prolactin receptor content of the N-nitrosomethylurea (NMU)-induced rat mammary tumour was investigated [20].
• The pituitary responsiveness to TRH was also determined in these two groups, challenged and unchallenged with oestradiol-benzoate [21].
• We found that chronic administration of oestradiol-benzoate significantly attenuated serum levels of leptin, in the dependence on the duration of its administration, and simultaneously decreased body weight [22].
• We have previously reported that oestrogens (oestradiol-benzoate) significantly decrease the body weight in male rats, increase anterior pituitary and serum levels of the intracellular messenger cAMP, which activates cAMP-dependent protein kinase A, their targets include hormone-sensitive lipase and they influence the brain sympathetic system [22].
• Administration OB produced a greater absolute increase in serum prolactin in old than in young female rats [23].

Analytical, diagnostic and therapeutic context of Hydroxyestrin benzoate

• To study this desensitization process in 5-day cyclic rats, females exhibiting regular 5-day vaginal cyclicity were ovariectomized on consecutive days of the cycle, injected with oestradiol benzoate (OB) or oil on the day of ovariectomy and autopsied 24 h after the injection [24].
• Then, intravenous injection of 100 microgram of ODB induced a rapid increase in MUA [25].
• Six of seven women in the control group and eight of eleven women treated with neuroleptic agents had LH surges to OB challenge [26].
• The LH/FSH responses to an intramuscular injection of age- and body weight-related doses of oestradiol benzoate (OB) were compared in intact gilts at 60 days of age with or without oestradiol-17 beta pretreatment from 30 to 52 days of age [27].
• All cows were treated with 1 mg ODB 1 day after intravaginal device removal (Day 9) [28].

References