A single day of constant light (L/L) provides immunity to behavioral despair in female rats maintained on an L/D cycle

2004 ◽  
Vol 28 (8) ◽  
pp. 1261-1265 ◽  
Author(s):  
Ajda Yilmaz ◽  
Ayla Aksoy ◽  
Resit Canbeyli
Keyword(s):  
Female Rats ◽  
Constant Light ◽  
Behavioral Despair

INTERACTIONS OF THE PINEAL AND EXPOSURE TO CONTINUOUS LIGHT ON ORGAN WEIGHTS OF FEMALE RATS

1961 ◽  
Vol 36 (4) ◽  
pp. 617-624 ◽  
Author(s):  
Richard Jay Wurtman ◽  
Willard Roth ◽  
Mark D. Altschule ◽  
Judith J. Wurtman
Keyword(s):  
Light Exposure ◽  
Continuous Light ◽  
Female Rats ◽  
Constant Light ◽  
Ovarian Weight ◽  
Organ Weights ◽  
Bovine Pineal Extracts ◽  
Pineal Extracts ◽  
Effect Of Light

ABSTRACT Either exposure to constant light for 80 days or pinealectomy produced similar changes in the weights of the ovaries and adrenals of female rats. These were not additive when both procedures were employed. Pinealectomy did not share with light-exposure the capacity to induce uterine hypertrophy. Rats exposed to constant light for 56 days had lighter pineals than animals kept in darkness; this decrease was not affected by administration of bovine pineal extracts. The increase in ovarian weight produced in rats by exposure to light for 56 days was prevented by bovine pineal extracts, but these extracts were without effect on the uterine hypertrophy produced under the same conditions. These data suggest that the effect of light upon the weight of the ovary is mediated via the pineal.

EFFECTS OF PINEALECTOMY AND CONSTANT LIGHT AND DARKNESS ON PROLACTIN LEVELS IN THE PITUITARY AND PLASMA AND ON PITUITARY ULTRASTRUCTURE OF THE RAT

1972 ◽  
Vol 54 (2) ◽  
pp. 263-NP ◽  
Author(s):  
R. RELKIN ◽  
M. ADACHI ◽  
S. A. KAHAN
Keyword(s):  
Plasma Concentrations ◽  
Virgin Female ◽  
Female Rats ◽  
Constant Light ◽  
Constant Darkness ◽  
Plasma Prolactin ◽  
Continuous Darkness ◽  
Prolactin Content ◽  
Intermediate Degree ◽  
Pituitary Prolactin

SUMMARY The effects of constant light, constant darkness and diurnal lighting, in combination with pinealectomy or sham-pinealectomy, on pituitary and plasma concentrations of radioimmunoassayable prolactin were investigated in 8-week-old male and virgin female rats. Two to three days after operation random groups of pinealectomized and sham-pinealectomized animals of the same sex were placed together in either continous light, continuous darkness or diurnal light, and killed 21 days later. Compared with sham-operated diurnally-illuminated controls, constant darkness caused a decrease in pituitary prolactin content and a rise in plasma prolactin levels. Pinealectomy or constant illumination reversed the effect of constant darkness, resulting in an increase in pituitary prolactin content and a fall in plasma prolactin levels when compared with sham-operated diurnally-illuminated controls. Electron microscopy of lactotrophic cells of the sham-pinealectomized animals exposed to constant darkness revealed few cytoplasmic granules, whereas these cells in the sham-pinealectomized animals exposed to constant light contained abundant granules; compared with the former groups, lactotrophic cells of sham-pinealectomized rats exposed to diurnal lighting revealed an intermediate degree of granulation.

Brief Communication: SEASONAL VARIABILITY IN BEHAVIORAL DESPAIR IN FEMALE RATS

2004 ◽  
Vol 114 (12) ◽  
pp. 1513-1520 ◽  
Author(s):  
A. AKSOY ◽  
D. SCHULZ ◽  
A. YILMAZ ◽  
R. CANBEYLI
Keyword(s):  
Seasonal Variability ◽  
Female Rats ◽  
Behavioral Despair

Ultrastructure of the Surface Epithelium of the Polycystic Ovary in Constant Light Rats

1982 ◽  
Vol 40 ◽  
pp. 240-241
Author(s):  
K. B. Singh ◽  
F. K. Khosho
Keyword(s):  
Electron Microscopy ◽  
Polycystic Ovary ◽  
Continuous Light ◽  
Female Rats ◽  
Constant Light ◽  
Surface Epithelium ◽  
Transmission Electron ◽  
Persistent Estrus ◽  
Microscopic Studies ◽  
Pco Syndrome

It is now well established that exposure of cyclic female rats to continuous light induces persistent estrus (PE), a syndrome which in many respects resembles the human polycystic ovary (PCO) syndrome. As in the human PCO, light microscopic studies of cystic ovaries of the constant light rat show numerous atretic follicles, and the surface epithelium grossly appears smooth and white. In the present study, we have utilized scanning (SEM) and transmission electron microscopy (TEM) to study changes on the surface epithelium of PCO in the constant light rat model.

Scanning Electron Microscopy of the Polycystic Ovary in Constant Light Rats

1981 ◽  
Vol 39 ◽  
pp. 538-539
Author(s):  
K. B. Singh ◽  
F. K. Khosho
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Polycystic Ovary ◽  
Three Dimensional ◽  
Continuous Light ◽  
Female Rats ◽  
Constant Light ◽  
Sprague Dawley ◽  
Polycystic Ovaries ◽  
Scanning Electron

Exposure of female rats to continuous light eventually induces persistent estrus (PE), a syndrome which in many respects resembles the human polycystic ovary syndrome. Light microscopic studies on the polycystic ovaries of constant light PE rats have been previously reported. In the present study, we have utilized scanning electron microscopy (SEM) to provide information regarding three-dimensional changes occurring on the surface of the polycystic ovary.Following exposure to continuous light for 50 days, PE was induced in a group of Sprague-Dawley female rats according to the procedure described elsewhere (2). Polycystic ovaries from constant light PE rats and ovaries from controls were fixed in 2.5% glutaraldehyde in 0.1M Na cacodylate buffer, pH 7.3 at room temperature for 24 hours. They were then cut into two equal halves along their long axis and fixed for an additional 3-4 hours. The specimens were processed for SEM studies by a modified OTOTO technique, dehydrated and critical point dried with CO2.

Ultrastructural Characteristics of Vaginal Epithelium of Persistent Estrous Rats

1985 ◽  
Vol 43 ◽  
pp. 658-659
Author(s):  
Khosho Francis K. ◽  
Kaufmann Robert C. ◽  
Amankwah Kofi S.
Keyword(s):  
Osmium Tetroxide ◽  
Uranyl Acetate ◽  
Ruthenium Red ◽  
Female Rats ◽  
Constant Light ◽  
Ultrastructural Changes ◽  
Vaginal Smears ◽  
Thin Sections ◽  
Cacodylate Buffer ◽  
Ultrastructural Characteristics

Adult female rats exposed to constant light will develop anovulatory acyclicity characterized by persistent vaginal cornification (PE) and formation of multiple large cystic follicles on the ovaries. The purpose of the present communication is to describe the ultrastructural changes in vaginal epithelia in PE rats as compared to that in normal estrous rats.Persistent vaginal estrous with PCO was induced in a group of Sprague-Dawely rats by exposure to constant light for 50-150 days. Rats in normal estrous, as determined by vaginal smears, were used as controls. Nembutal- anethesized rats were perfused through the aorta with 2.5% gluteraldehyde in 1M sodium cacodylate buffer (pH 7.3). The mucosa of the vaginal folds just inferior to the cervix were dissected by microsurgery, postfixed, stained with 0.5% ruthenium red in 1% osmium tetroxide, dehydrated, and embedded in polybed. Thick sections (1μ) were stained with toludine blue for light microscopy studies. Thin sections were stained with uranyl acetate and lead citrate.

Surface Changes in Vaginal Epithelial Cells During Persistent Estrous Rats

1985 ◽  
Vol 43 ◽  
pp. 656-657
Author(s):  
Khosho Francis K. ◽  
Kaufmann Robert C. ◽  
Amankwah Kofi S.
Keyword(s):  
Polycystic Ovary ◽  
Female Rats ◽  
Constant Light ◽  
Major Influence ◽  
Surface Epithelium ◽  
Female Rat ◽  
Vaginal Epithelial Cells ◽  
Cacodylate Buffer ◽  
And Control ◽  
Scanning Electron

Light exerts a major influence on the reproductive functions of the female rat, and the presence of constant light results in an aberrant vaginal cycle, leading to infertility associated with polycystic ovary (PCO) syndrome. In the present communication, we have utilized scanning electron microscopy (SEM) to study changes on the surface epithelium of persistent estrous (PE) rats with PCO.Sprague-Dawely female rats were exposed to constant light for 50-150 days according to protocol that has been previously described. Rats in normal estrous, as determined by vaginal smears, were used as controls. Nembutal- anesthesized rats were perfused through the aorta with 2.5% gluteraldehyde in 0.1M sodium cacodylate buffer (pH 7.3). The mucosa of the upper third of the vagina from PE and control rats were microdissected, processed for SEM studies by a modified 0T0T0 technique, dehydrated, and critical point dried with C02- The specimens were examined in a Hitachi scanning electron microscope Model S-500.

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