THE EFFECT OF NEONATAL ADMINISTRATION OF SEX HORMONES ON THE TURNOVER OF HEPATIC MICROSOMAL PHOSPHOLIPID IN MALE AND FEMALE RATS

1971 ◽  
Vol 49 (4) ◽  
pp. 659-665 ◽  
Author(s):  
Y. C. TOH
Keyword(s):  
Testosterone Propionate ◽  
Liver Microsomes ◽  
Total Content ◽  
P Uptake ◽  
Female Rats ◽  
Radioactive Phosphorus ◽  
Male And Female ◽  
Male And Female Rats ◽  
Neonatal Administration ◽  
Microsomal Phospholipid

SUMMARY The effect of neonatal administration of testosterone propionate and oestradiol benzoate on the metabolism of microsomal phospholipid in the liver of male and female rats was studied. Males had a greater uptake of radioactive phosphorus than females. Gonadectomy at the age of 4 weeks reduced the incorporation of 32P into the microsomal phospholipid. Administration of testosterone significantly increased 32P uptake both in the intact and ovariectomized females as well as in the castrated males, whereas oestradiol produced no effect. A sex difference of total microsomal phospholipid phosphorus was also found in the gonadectomized rats. Oestrogen caused no change in the intact animals but restored the level of phospholipid in ovariectomized female rats. On the other hand, testosterone significantly increased the total content of the phospholipid in the liver microsomes of both intact and gonadectomized male and female rats.

GONADOTROPHIN PATTERNS IN MALE AND FEMALE RATS:

1968 ◽  
Vol 58 (4) ◽  
pp. 600-612 ◽  
Author(s):  
Robert Boyd ◽  
Donald C. Johnson
Keyword(s):  
Ascorbic Acid ◽  
Testosterone Propionate ◽  
Female Rats ◽  
Female Rat ◽  
Feedback Effects ◽  
Male And Female ◽  
Prostate Weight ◽  
Male And Female Rats ◽  
Males And Females ◽  
Normal Males

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.

Aspartic acid administered neonatally affects ventilation of male and female rats differently

1986 ◽  
Vol 61 (2) ◽  
pp. 780-784 ◽  
Author(s):  
E. H. Schlenker ◽  
M. Goldman
Keyword(s):  
Aspartic Acid ◽  
Ventilatory Response ◽  
Minute Ventilation ◽  
Female Rats ◽  
Male Rats ◽  
Metabolic Rates ◽  
Control Male ◽  
Male And Female ◽  
Male And Female Rats ◽  
Neonatal Administration

In this study ventilation was evaluated in 12-mo-old male and female rats who had received large doses of aspartic acid neonatally. Rats of both sexes treated with aspartic acid were obese, stunted, and exhibited hypogonadism. Although metabolic rates of the aspartic acid-treated rats were not different compared with sex-matched controls, ventilatory patterns were different. Aspartic acid-treated females breathed with a smaller tidal volume (VT), higher frequency (f), and similar minute ventilation (VE) compared with control females. This pattern is commonly observed in many patients who are obese. The aspartic acid-treated females responded to hypercapnic and hypoxic challenges by increasing f more than VT. Tissue pocket gases (PCO2 and PO2) of aspartic acid-treated females were normal. In contrast, aspartic acid-treated males hypoventilated compared with control males. Tissue pocket gas values suggested that aspartic acid-treated males were hypoxemic and hypercapnic. Moreover, the response of aspartic acid-treated males to hypercapnia was parallel to but was less than that of control male rats. The ventilatory response of aspartic acid-treated male rats to hypoxia was blunted. This study has shown that neonatal administration of aspartic acid causes a decreased ventilation and blunted response to hypoxia in adult male but not female rats.

INHIBITION OF SEXUAL DEVELOPMENT IN MALE AND FEMALE RATS TREATED WITH VARIOUS STEROIDS AT THE AGE OF FIVE DAYS

1965 ◽  
Vol 49 (2) ◽  
pp. 193-206 ◽  
Author(s):  
Fred A. Kind ◽  
A. Folch Pi ◽  
M. Maqueo ◽  
L. Herrera Lasso ◽  
A. Oriol ◽  
...  
Keyword(s):  
Sexual Development ◽  
Testosterone Propionate ◽  
Female Rats ◽  
Male And Female ◽  
Male And Female Rats

ABSTRACT The effect of various steroids injected into 5 day old male and female rats was evaluated at the age of 45 days. In the males the degree in which testes and accessory sex tissues were atrophied, and in the females the degree of inhibition of luteinization were the indices. Various synthetic oestrogens were potent inhibitors of sexual development in both sexes while androgens were less active. The activity of several oestrogens in this test does not correlate with oestrogenic potency as measured in the uterotrophic test. Testosterone propionate produced moderate atrophy of testes and accessory sex tissue but spermatogenesis was not impaired.

PREVENTION OF CENTRAL DEFEMINIZATION BUT NOT MASCULINIZATION IN MALE RATS BY INHIBITION NEONATALLY OF OESTROGEN BIOSYNTHESIS

1977 ◽  
Vol 74 (3) ◽  
pp. 375-382 ◽  
Author(s):  
J. T. M. VREEBURG ◽  
PAULA D. M. VAN DER VAART ◽  
P. VAN DER SCHOOT
Keyword(s):  
Sexual Function ◽  
Ovarian Function ◽  
Testosterone Propionate ◽  
Neonatal Period ◽  
Female Rats ◽  
Male Rats ◽  
Normal Male ◽  
Male And Female ◽  
Male And Female Rats ◽  
Copulatory Behaviour

SUMMARY An inhibitor of aromatization, androsta-1,4,6-triene-3,17-dione (ATD), was administered to newborn male and female rats and various parameters of gonadal and sexual function were examined in adulthood. Males injected with 1 mg ATD on the day of birth (day 1) and on days 3, 5, 10 and 15 postnatally, subsequently (day 55) showed normal male and female copulatory behaviour, but were not able to maintain cyclicity in ovarian transplants. When the ATD was administered by Silastic implants, however, cyclicity in ovarian transplants did occur. Neither form of treatment brought about significant changes in neonatal plasma or testicular testosterone concentrations. Female rats implanted on day 3 of life with Silastic capsules containing ATD and then given an injection of 0·25 mg testosterone propionate on day 5 subsequently showed normal ovarian function, whereas the controls receiving only testosterone propionate showed persistent vaginal cornification, anovulation and polyfollicular ovaries. The results support the view that the central conversion of testicular androgens to oestrogens during the neonatal period is necessary to abolish cyclic gonadotrophin release and to suppress female copulatory behaviour.

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