Evidence for a Free-Running Circadian Rhythm in Pituitary-Adrenal Function in Blinded Adult Female Rats

1976 ◽  
Vol 20 (4) ◽  
pp. 289-295 ◽  
Author(s):  
M.M. Wilson ◽  
R.W. Rice ◽  
V. Critchlow
Keyword(s):  
Circadian Rhythm ◽  
Adult Female ◽  
Adrenal Function ◽  
Female Rats ◽  
Free Running

CIRCADIAN RHYTHM OF PLASMA CORTICOSTEROID IN ADULT FEMALE RATS: CHRONOLOGICAL SHIFTS IN ABNORMAL LIGHTING REGIMENS AND CONNECTION WITH OESTROUS CYCLE

1975 ◽  
Vol 80 (3) ◽  
pp. 527-541 ◽  
Author(s):  
Yasuhiko Morimoto ◽  
Tatsuo Oishi ◽  
Kazutaka Arisue ◽  
Zensuke Ogawa ◽  
Fumiko Tanaka ◽  
...  
Keyword(s):  
Circadian Rhythm ◽  
Adult Female ◽  
Female Rats ◽  
Constant Light ◽  
Constant Darkness ◽  
Vaginal Smear ◽  
Free Running ◽  
Normal Light ◽  
Lighting Regimen ◽  
Day By Day

ABSTRACT The circadian rhythm of plasma corticosteroid (CS) levels in adult female rats was studied chronologically under the following conditions: normal light-dark (LD), inverted light-dark (DL), constant dark (DD) and constant light (LL). Animals were accustomed to LD condition for 7 days before exposure to each abnormal lighting regimen. Normal circadian rhythm established under LD condition was clearly inverted on the third day of DL regimen, and the inverted rhythm persisted thereafter under DL condition. The circadian CS rhythm persisted essentially unchanged throughout DD condition, but lost its regular periodicity showing "free running" and changed day by day under LL condition. The average CS levels over a 24 h period were higher under LL than under DD condition. Plasma CS levels in each lighting regimen exhibited diurnal variations regardless of the vaginal smear patterns of autopsied animals. Exposure of rats to LL for 21 days made the circadian CS rhythm flat, but induced persistent oestrus in only a few animals. The data suggest that (1) an unexpectedly rapid inversion of the circadian CS rhythm occurs if animals are exposed to inverted light-dark environment; (2) constant darkness seems to be a near-natural environment for rats, and changes little of the pre-established circadian CS rhythm; (3) constant light, on the contrary, is assumed to be a stress for rats, and disrupts the circadian CS rhythm and elevates CS levels; (4) the change in circadian CS rhythm in adult female rats is not mediated by a change in gonadal function and the two conditions may not be connected directly with each other.

DAILY RHYTHM IN SECRETION OF PROLACTIN IN ANDROGENIZED FEMALE RATS

1980 ◽  
Vol 87 (3) ◽  
pp. 327-332 ◽  
Author(s):  
LEAH YOGEV ◽  
JOSEPH TERKEL
Keyword(s):  
Circadian Rhythm ◽  
Adult Female ◽  
Testosterone Propionate ◽  
Prolactin Secretion ◽  
Daily Rhythm ◽  
Female Rats ◽  
Cervical Stimulation

Androgen-sterilized female rats were obtained by administering 10 μg testosterone propionate to pups on day 2 after birth. In contrast with ovariectomized adults, androgenized adult female rats are incapable of responding to cervical stimulation by secreting prolactin in the nocturnal surge pattern. In spite of the loss of this pattern the androgenized female rats still exhibited a daily circadian rhythm of prolactin secretion with afternoon levels three times higher than those after midnight.

CORTICOSTEROID-UMSATZ UND CORTICOSTEROID-PRODUKTION BEI RATTEN UNTER DER BEHANDLUNG MIT ANABOLEN STEROIDEN

1965 ◽  
Vol 48 (2) ◽  
pp. 263-271 ◽  
Author(s):  
Herbert Schriefers ◽  
Gerlinde Scharlau ◽  
Franzis Pohl
Keyword(s):  
Production Rate ◽  
Adult Female ◽  
Anabolic Steroids ◽  
Reduction Rate ◽  
Female Rats ◽  
Adrenal Weight ◽  
Hydrogenase Activity ◽  
Anabolic Effect ◽  
Liver Slices

ABSTRACT After the administration of anabolic steroids to adult female rats in daily doses of 1 mg per animal for 14 days, the following parameters were investigated: the rate of the Δ4-5α-hydrogenase-catalyzed cortisone reduction in liver slices and microsomal fractions, the adrenal weight and the in vitro corticosterone production rate. Among the steroids tested, only 17α-methyl-testosterone and 17α-ethyl-19-nor-testosterone were effective in lowering significantly cortisone reduction rate by liver slices with concomitant decreases in microsomal Δ4-5α-hydrogenase-activity. Testosterone, 19-nor-testosterone, 17α-ethinyl-19-nor-testosterone, 17α-methyl-17β-hydroxy-androsta-1,4-dien-3-one and 1-methyl-17β-hydroxy-androst-1-en-3-one were ineffective or only slightly effective. Adrenal weight and absolute corticosterone production rate (μg/60 min per animal) were decreased after treatment with 17α-methyl-testosterone, 17α-ethyl-19-nor-testosterone and 1-methyl-17β-hydroxy-androst-1-en-3-one. Corticosterone production was decreased with 17α-ethinyl-19-nor-testosterone in spite of an unchanged adrenal weight. The relative corticosterone production rate (μg/60 min · 100 mg adrenal) was in any cases unaffected. According to these results there exists – with the exception of 17α-ethinyl-19-nor-testosterone – a strict parallelism between corticosteroid turnover and corticosterone production rate: unchanged turnover is correlated with unchanged corticosterone production rate, while a decreased turnover is correlated with decreased adrenal activity. The protein-anabolic effect of certain anabolic steroids may be partly due to an anti-catabolic action of these compounds resulting from a decreased corticosteroid inactivation and production rate. Possible mechanisms by which anabolic steroids may affect corticosteroid-balance are discussed.

THE HYPOTHALAMUS AND PROPYLTHIOURACIL-INDUCED GOITRE IN THE RAT

1963 ◽  
Vol 42 (2) ◽  
pp. 254-262 ◽  
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.

BEFUNDE AM GENITALTRAKTUS DER RATTE NACH CORTICOTROPIN-INJECTION UND IHRE DEUTUNG UNTER BERÜCKSICHTIGUNG DES ZELLBILDES DER ADENOHYPOPHYSE

1959 ◽  
Vol XXXII (II) ◽  
pp. 167-176 ◽  
Author(s):  
Walter Schätzle
Keyword(s):  
Adult Female ◽  
Single Injection ◽  
Anterior Lobe ◽  
Vaginal Epithelium ◽  
Female Rats ◽  
Normal Adult ◽  
List Type

ABSTRACT In normal adult female rats a single injection of 5 IU corticotrophin was followed by a retention of glucoproteid material in the anterior lobe of the hypophysis and by impairment of the luteinization. In spayed adult female rats the same corticotrophin administration caused stratification and mucification of the vaginal epithelium.

Eugenol improves tissue damage and oxidative stress in adult female rats after ovarian torsion/detorsion

2021 ◽  
pp. 1-6
Author(s):  
Bita Barghi ◽  
Majid Shokoohi ◽  
Amir Afshin Khaki ◽  
Arash Khaki ◽  
Maryam Moghimian ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Adult Female ◽  
Tissue Damage ◽  
Ovarian Torsion ◽  
Female Rats ◽  
And Oxidative Stress

scholarly journals Adult female rats perinatally exposed to perfluorohexane sulfonate (PFHxS) and a mixture of endocrine disruptors display increased body/fat weights without a transcriptional footprint in fat cells

2021 ◽  
Vol 339 ◽  
pp. 78-87
Author(s):  
Cecilie Nethe Ramskov Tetzlaff ◽  
Louise Ramhøj ◽  
Aurélie Lardenois ◽  
Marta Axelstad ◽  
Bertrand Evrard ◽  
...  
Keyword(s):  
Endocrine Disruptors ◽  
Body Fat ◽  
Adult Female ◽  
Female Rats ◽  
Fat Cells
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