The Affinity of Catechol Estrogens for Estrogen Receptors the Pituitary and Anterior Hypothalamus of the i n Rat

ABSTRACT Electrolytic lesions were placed in the anterior hypothalamus of 3–4 day-old female rats; vaginal opening was hastened in comparison with blank-operated littermates in 12 of 17 rats bearing a lesion in the basal supra-and post-chiasmatic area. In the animals with the earliest vaginal opening, lesions reached upward towards the region of the anterior commissure and the paraventricular nuclei. The degree of advancement of puberty in rats operated at the age of 3 or 4 days was similar to that caused by lesions made at 10, 14 or 15 days. This finding suggests that the effect of a lesion upon gonadotrophin secretion does not begin to take place until after the age of at least two weeks.

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THE HYPOTHALAMUS AND PROPYLTHIOURACIL-INDUCED GOITRE IN THE RAT

Acta Endocrinologica ◽

10.1530/acta.0.0420254 ◽

1963 ◽

Vol 42 (2) ◽

pp. 254-262 ◽

Cited By ~ 2

Author(s):

J. J. van der Werff ten Bosch ◽

H. E. Swanson

Keyword(s):

Steady State ◽

Thyroid Hormone ◽

Adult Female ◽

Normal Diet ◽

Anterior Hypothalamus ◽

Female Rats ◽

Intact Rats

ABSTRACT Adult female rats were given a normal diet, or a diet which contained 0.15% propylthiouracil. At the beginning of the experiment one half of the rats were left intact, whilst the others received an electrolytic basal midline lesion in the anterior hypothalamus. Of each of the four groups of rats, one half was killed after 14 days, the others after 28 days. It was found (both after 14 and after 28 days) that the presence of a lesion reduced the thyroid weight to approximately 75% of the value in intact rats on the same diet, which might be normal or contain propylthiouracil. Propylthiouracil caused thyroid enlargement (to 278% after 14 days and 352–360% after 28 days) in intact rats as compared with intact rats on a normal diet, and in lesioned rats as compared with lesioned rats on a normal diet. It is concluded that lesions cause a lowered steady state of the thyroid-pituitary feed-back system, but that this system responds normally to the alteration of the steady state caused by the propylthiouracil-induced block in thyroid hormone output.

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IN VITRO UPTAKE OF TRITIATED OESTRADIOL BY THE ANTERIOR HYPOTHALAMUS AND HYPOPHYSIS OF THE RAT

Acta Endocrinologica ◽

10.1530/acta.0.0640687 ◽

1970 ◽

Vol 64 (4) ◽

pp. 687-695 ◽

Cited By ~ 10

Author(s):

Junzo Kato

Keyword(s):

Incubation Medium ◽

Posterior Hypothalamus ◽

Anterior Hypothalamus ◽

Ovariectomized Rats ◽

Free Medium ◽

Cortex Cerebri ◽

Anterior Hypophysis ◽

In Vitro Uptake

ABSTRACT The anterior, middle, and posterior hypothalamus, the cortex cerebri, the anterior hypophysis as well as the diaphragm of adult ovariectomized rats were incubated in vitro with tritiated 17β-oestradiol. The uptake of tritiated oestradiol was differentially distributed intracerebrally with higher accumulation in the anterior hypothalamus and the hypophysis. Lowering the temperature of the incubation medium caused a reduction in the uptake of radioactivity by the anterior hypothalamus as compared to that found in other brain tissues. Tritiated oestradiol taken up in vitro by the anterior hypothalamus and the hypophysis tended to be retained after further incubation in a steroid-free medium. The addition of non-radioactive 17β-oestradiol to the medium inhibited the uptake of tritiated oestradiol by these tissues. Moreover, pretreatment with non-radioactive 17β-oestradiol in vivo prevented the preferential accumulation of tritiated oestradiol in vitro in the anterior hypothalamus and the hypophysis. These results indicate that oestradiol is preferentially taken up in vitro by the anterior hypothalamus and the hypophysis of the rat.

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