scholarly journals The relationship between ovulation and the changes in thyroid gland activity that occur during the oestrous cycle in rats, mice and hamsters

1966 ◽  
Vol 184 (2) ◽  
pp. 402-417 ◽  
Author(s):  
K. Brown-Grant
Keyword(s):  
Thyroid Gland ◽  
Oestrous Cycle ◽  
The Relationship ◽  
Thyroid Gland Activity

THE INDUCTION OF OVULATION DURING PREGNANCY IN THE RAT

1969 ◽  
Vol 43 (4) ◽  
pp. 529-538 ◽  
Author(s):  
K. BROWN-GRANT
Keyword(s):  
Thyroid Gland ◽  
Early Pregnancy ◽  
Concentration Ratio ◽  
Ovarian Follicles ◽  
Follicle Development ◽  
Induction Of Ovulation ◽  
Oestradiol Benzoate ◽  
The Relationship ◽  
Thyroid Gland Activity

SUMMARY Ovarian follicles develop to the stage where they are competent to ovulate in response to exogenous gonadotrophin at the same rate during early pregnancy as in a normal 4-day cycle in the rat. The length of time during which this competency is retained appears to be shorter than after the blockade of ovulation by pentobarbitone administered at pro-oestrus in rats that are not pregnant. Evidence from oviduct:plasma (O:P) and uterus:plasma (U:P) 131I ratio measurements indicating high progesterone and low oestrogen levels at this stage of pregnancy may be relevant to this finding. Some evidence for a 3-day cycle of follicle development after day 6 of pregnancy was obtained but the high O:P ratios suggest that little oestrogen secretion is associated with this. Oestradiol benzoate (6·25–100 μg.) administered after day 3 of pregnancy will induce ovulation when competent follicles are present. The thyroid:plasma (T:P) concentration ratio for 131I does not rise in association with ovulation induced by exogenous gonadotrophin. After oestrogen administration, the T:P ratio may increase regardless of whether ovulation is induced or not. The results are discussed in relation to the studies of other workers on the induction of ovulation during pregnancy and to earlier work on the relationship between ovulation and changes in thyroid gland activity.

Taste sensitivity in various strains of mice

1962 ◽  
Vol 202 (6) ◽  
pp. 1200-1204 ◽  
Author(s):  
Keiichiro Hoshishima ◽  
Sadasuke Yokoyama ◽  
Katsuo Seto
Keyword(s):  
Acetic Acid ◽  
Sodium Chloride ◽  
Thyroid Gland ◽  
Taste Sensitivity ◽  
The Relationship ◽  
Taste Thresholds

The present study was designed to elucidate the differences in taste sensitivity in various strains of mice, and to study the relationship between taste sensitivity and color of the fur. Taste thresholds for four kinds of taste substance, i.e., sodium chloride, saccharine, acetic acid, and phenylthiocarbamide (PTC), were measured with three black and three white strains of mice. Taste sensitivity in mice with hypofunction of the suprarenal body, thyroid gland, and liver was also studied to clarify the bearing of the functions of those organs on the sense of taste. The taste sensitivity of mice differed according to strain. A white strain (aa) showed the lowest taste thresholds for all substances tested, whereas a black strain (0–61) showed the highest. Other strains showed intermediate thresholds, the white strains showing lower ones except in the case of saccharine. Hypofunction of the suprarenal body, thyroid gland, and liver caused a rise in the taste thresholds: a) after cauterization of the suprarenal body, the threshold for acetic acid was raised, whereas those for other taste substances were unchanged; b) reduction of thyroid and hepatic functions resulted in a rise of the taste thresholds for saccharine, acetic acid, and PTC.

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