Effects of Neonatally-Administered DDT Homologs on Reproductive Function in Male and Female Rats

1974 ◽  
Vol 16 (2) ◽  
pp. 84-94 ◽  
Author(s):  
R.J. Gellert ◽  
W.L. Heinrichs ◽  
R. Swerdloff
1967 ◽  
Vol 54 (1) ◽  
pp. 189-192 ◽  
Author(s):  
Fred A. Kind ◽  
G. Benagiano

ABSTRACT One and five day old male and female rats were pinealectomized and their reproductive function studied when they matured. In females the fertility index was similar to untreated or sham operated groups. However, the females matured 8 to 9 days earlier as evidenced by the opening of the vaginal membrane. In males pinealectomy had no influence on testes development and accessory sex tissue weights. It is concluded that the regulatory function of the pineal gland with respect to gonadal function is a minor one.


1978 ◽  
Vol 56 (5) ◽  
pp. 747-753 ◽  
Author(s):  
Edwin A. Knecht ◽  
Gary L. Wright ◽  
Mark A. Toraason

Reproductive function of male and female rats was examined in relation to periodic, short-term heat treatment. Daily exposure to an environmental temperature of 38.2 °C for 55 min elevated rectal temperatures to 39.9 and 41.2 °C in male and female rats, respectively. Heat exposure tended to decrease copulation in males cohabitated with unhealed females. The rate of conception was affected similarly, and fetal survival tended to be reduced by paternal heat treatment. Estrous cycles were disrupted initially in heat-exposed females, but the rate of copulation and conception of females cohabitated with unheated males was unaltered by heat treatment. However, maternal heat exposure impaired prenatal survival and growth. During lactation, a high incidence of maternal and pup deaths was observed at approximately 14 days postpartum. Maternal deaths were coincident with a decrease in thermoregulatory ability and rectal temperatures exceeding 42 °C.


2000 ◽  
Vol 19 (5) ◽  
pp. 284-296 ◽  
Author(s):  
T Nagao ◽  
Y Saito ◽  
K Usumi ◽  
M Nakagomi ◽  
S Yoshimura ◽  
...  

A number of alkylphenolic compounds are used in a variety of commercial products and have been shown in in vitro studies to be weakly estrogenic, but few in vivo data are available addressing this issue in mammals. Human ex-posure to alkylphenols may occur not only from these environmental contaminants but also through contact with manufactured and metabolic breakdown products. The reproductive function of rats treated subcutaneously with nonylphenol (NP, 500 mg/kg/day) or 17Q3-estradiol (E2, 2 mg/kg/day) as a positive control, from postnatal days 1 to 5 was examined after puberty. In addition, masculine sexual behavior, sperm motion, plasma testosterone concentration and histopathological changes in the reproductive organs of the rats were examined. Furthermore, male rats were subjected to an open field test and wheel cage test to evaluate locomotor activity, and the estrous cycle was examined in female rats. All male and female rats exposed neonatally to NP or E2 showed macroscopic and/or microscopic altera-tions of the gonads. Females treated with NP or E2 showed an altered estrous cycle and abnormal reproductive function, while males treated with NP or E2 showed normal reproduc-tion. In males exposed neonatally to NP or E2, no abnorm-alities were observed in locomotor activity, sperm motion or plasma testosterone concentration. The results of this study indicate that early neonatal exposure to NP causes dysfunc-tion of postpubertal reproductive function in female rats, as well as disrupted development of gonads in male and female rats. More detailed studies are warranted to assess the possible risks to human and wildlife reproduction from exposure to NP and other environmental chemicals with estrogenic activity.


1961 ◽  
Vol 38 (1) ◽  
pp. 50-58 ◽  
Author(s):  
N. E. Borglin ◽  
L. Bjersing

ABSTRACT Oestriol (oestra-1,3,5(10)-triene-3,16α,17β-triol) is a weakly oestrogenic substance which, however, in contrast to what was formerly believed, is of physiological significance. Its effect is localized largely to the uterine cervix and vagina. Clinical experience argues both for and against an effect on the pituitary gland. This investigation is concerned with the morphological changes in the pituitary gland and adrenal cortex of gonadectomized male and female rats after the injection of oestriol. It was found that oestriol has the same type of action on these glands as other oestrogens, but under the experimental conditions used, this effect proved much weaker than that produced by oestradiol (oestra-1,3,5(10)-triene-3,17β-diol).


1973 ◽  
Vol 74 (1) ◽  
pp. 88-104 ◽  
Author(s):  
T. Jolín ◽  
M. J. Tarin ◽  
M. D. Garcia

ABSTRACT Male and female rats of varying ages were placad on a low iodine diet (LID) plus KClO4 or 6-propyl-2-thiouracil (PTU) or on the same diet supplemented with I (control rats). Goitrogenesis was also induced with LID plus PTU in gonadectomized animals of both sexes. The weight of the control and goitrogen treated animals, and the weight and iodine content of their thyroids were determined, as well as the plasma PBI, TSH, insulin and glucose levels. The pituitary GH-like protein content was assessed by disc electrophoresis on polyacrylamide gels. If goitrogenesis was induced in young rats of both sexes starting with rats of the same age, body weight (B.W.) and pituitary growth hormone (GH) content, it was found that both the males and females developed goitres of the same size. On the contrary, when goitrogenesis was induced in adult animals, it was found that male rats, that had larger B.W. and pituitary GH content than age-paired females, developed larger goitres. However, both male and female rats were in a hypothyroid condition of comparable degree as judged by the thyroidal iodine content and the plasma PBI and TSH levels. When all the data on the PTU or KClO4-treated male and female rats of varying age and B.W. were considered together, it was observed that the weights of the thyroids increased proportionally to B.W. However, a difference in the slope of the regression of the thyroid weight over B.W. was found between male and female rats, due to the fact that adult male rats develop larger goitres than female animals. In addition, in the male rats treated with PTU, gonadectomy decreased the B.W., pituitary content of GH-like protein and, concomitantly, the size of the goitre decreased; an opposite effect was induced by ovariectomy on the female animals. However, when goitrogenesis was induced in weight-paired adult rats of both sexes, the male animals still developed larger goitres than the females. Among all the parameters studied here, the only ones which appeared to bear a consistent relationship with the size of the goitres in rats of different sexes, treated with a given goitrogen, were the rate of body growth and the amount of a pituitary GH-like protein found before the onset of the goitrogen treatment. Moreover, though the pituitary content of the GH-like protein decreased as a consequence of goitrogen treatment, it was still somewhat higher in male that in female animals. The present results suggest that GH may somehow be involved in the mechanism by which male and female rats on goitrogens develop goitres of different sizes, despite equally high plasma TSH levels.


1968 ◽  
Vol 58 (4) ◽  
pp. 600-612 ◽  
Author(s):  
Robert Boyd ◽  
Donald C. Johnson

ABSTRACT The effects of various doses of testosterone propionate (TP) upon the release of luteinizing hormone (LH or ICSH) from the hypophysis of a gonadectomized male or female rat were compared. Prostate weight in hypophysectomized male parabiotic partners was used to evaluate the quantity of circulating LH. Hypophyseal LH was measured by the ovarian ascorbic acid depletion method. Males castrated when 45 days old secreted significantly more LH and had three times the amount of pituitary LH as ovariectomized females. Administration of 25 μg TP daily reduced the amount of LH in the plasma, and increased the amount in the pituitary gland, in both sexes. Treatment with 50 μg caused a further reduction in plasma LH in males, but not in females, while pituitary levels in both were equal to that of their respective controls. LH fell to the same low level in partners of males or females receiving 100 μg TP. When gonadectomized at 39 days, males and females had the same amount of plasma LH, but males had more stored hormone. Pituitary levels were unchanged from controls following treatment with 12.5, 25 or 50 μg TP daily, but plasma values dropped an equal amount in both sexes with the latter two doses. Androgenized males or females, gonadectomized when 39 days old, were very sensitive to the effects of TP and plasma LH was significantly reduced with 12.5 μg daily. Pituitary LH in androgenized males was higher than that of normal males but was reduced to normal by small amounts of TP. The amount of stored LH in androgenized females was not different from that of normal females and it was unchanged by any dose of TP tested. Results are consistent with the conclusion that the male hypothalamic-hypophyseal axis is at least as sensitive as the female axis to the negative feedback effects of TP. Androgenization increases the sensitivity to TP in both males and females.


1988 ◽  
Vol 117 (4_Suppl) ◽  
pp. S191-S192
Author(s):  
M. STOPPOK ◽  
H. SCHRIEFERS ◽  
E. R. LAX

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