Abstract:Ovaries of immature mice were painted with 9:IO-dimethyl-l:2-benzanthracene ( D M B A ) , and the effect of the carcinogen on the number of oocytes as well as
“…This finding of the present study conforms with the observations of Krarup (1970a) and Krarup and Loff (1971). Depletion of the oocytes by DMBA treatment is followed by ovarian tumorigenesis (Krarup, 1967(Krarup, , 1970b.…”
The influence of pregnant mare serum gonadotropin (PSGM) on the induction of ovarian tumors by carcinogen(DMBA) and/or mutagens (EMS and BMS) has been studied in Swiss albino mice. Priming of the ovaries of 6-week-old mice with PMSG (50 IU/mouse) 24 h before intragastric intubation of DMBA (5 mg/mouse) resulted in a significant increase in ovarian tumors when harvested 6 months after the treatment. A similar experiment done on 8-week-old mice yielded confirmatory results. Mutagens (EMS and BMS) failed, at given dose levels (200 mg/kg and 300 mg/kg body weight), to induce tumors in normal as well as PMSG-primed ovaries. Pretreatment of animals with PMSG-enhanced DMBA-induced oocyte depletion and also increased the DMBA-3H activity in the ovaries. The augmentation of DMBA-induced tumors in PMSG-primed ovaries could be due to increased uptake of DMBA and increased depletion of oocytes. It is also possible that PMSG-primed ovaries provided more proliferating granulosa cells (and macromolecules) for the interaction of DMBA (or its metabolites) and thereby increased the chances of cell transformation in the ovaries.
“…This finding of the present study conforms with the observations of Krarup (1970a) and Krarup and Loff (1971). Depletion of the oocytes by DMBA treatment is followed by ovarian tumorigenesis (Krarup, 1967(Krarup, , 1970b.…”
The influence of pregnant mare serum gonadotropin (PSGM) on the induction of ovarian tumors by carcinogen(DMBA) and/or mutagens (EMS and BMS) has been studied in Swiss albino mice. Priming of the ovaries of 6-week-old mice with PMSG (50 IU/mouse) 24 h before intragastric intubation of DMBA (5 mg/mouse) resulted in a significant increase in ovarian tumors when harvested 6 months after the treatment. A similar experiment done on 8-week-old mice yielded confirmatory results. Mutagens (EMS and BMS) failed, at given dose levels (200 mg/kg and 300 mg/kg body weight), to induce tumors in normal as well as PMSG-primed ovaries. Pretreatment of animals with PMSG-enhanced DMBA-induced oocyte depletion and also increased the DMBA-3H activity in the ovaries. The augmentation of DMBA-induced tumors in PMSG-primed ovaries could be due to increased uptake of DMBA and increased depletion of oocytes. It is also possible that PMSG-primed ovaries provided more proliferating granulosa cells (and macromolecules) for the interaction of DMBA (or its metabolites) and thereby increased the chances of cell transformation in the ovaries.
“…Ongoing apoptosis or necrosis and decreases in the reserve pool of small follicles usually are detectable by qualitative microscopic examination. Degeneration of oogonia in utero or in the immediate postnatal period may cause significant depletion of primordial follicles that would likely be further exacerbated in adults due to continued recruitment for growth from the already depleted primordial pool (Mandl and Zuckerman, 1952;Krarup, 1969;Murphy and Beamer, 1973;Hirshfield, 1994). These changes are discernible to a pathologist conducting a focused qualitative examination of the ovary.…”
Section: Qualitative Assessment Of the Ovarymentioning
“…A number of studies have shown that exposure to ovarian toxicants can lead to oocyte destruction Krarup et al, 1967;1969;1970;Maronpot, 1987;Melnick et al, 1990). How these effects are produced is becoming better understood and detailed for a number of chemical classes discussed herein.…”
Section: Impact Of Environmental Chemical Exposures On Follicular Atrmentioning
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