PROGESTERONE IN THE EXPERIMENTAL CONTROL OF THE BEHAVIOURAL SEX CYCLE IN THE FEMALE RAT

1967 ◽  
Vol 38 (3) ◽  
pp. 269-277 ◽  
Author(s):  
I. ZUCKER
Keyword(s):  
Oestrous Cycle ◽  
Female Rat ◽  
Experimental Control ◽  
Biphasic Effect ◽  
Sex Cycle

SUMMARY The effect of injections of progesterone on the length of the behavioural oestrous cycle in rats is described. Administration of the hormone was shown to act differently in rats known to have a 4-day cycle as compared with animals with a 5-day cycle. In the 4-day rat injection of 2 mg. progesterone on the first, second or third day of the cycle retarded the next occurrence of behavioural oestrus by 1–2 days; treatment on day 4 of the cycle was without effect. In 5-day rats treatment with progesterone before day 3 of the cycle delayed the occurrence of behavioural heat in only 35% of animals; treatment on day 3 retarded the occurrence of heat by 1–3 days in all rats. Injections on day 4 advanced heat by 1 day and treatment on day 5 was without effect. Additional experiments compared the responsiveness to progesterone of 'artificial' and natural 5-day rats. The results suggest a biphasic effect of progesterone on induction of behavioural receptivity with time characteristics similar to those observed earlier for ovulation and vaginal cyclicity.

Role of the subcommissural organ in the control of gonadotrophin secretion in the female rat

1982 ◽  
Vol 95 (2) ◽  
pp. 207-213 ◽  
Author(s):  
Patrizia Limonta ◽  
Roberto Maggi ◽  
Luciano Martini ◽  
Flavio Piva
Keyword(s):  
Subcommissural Organ ◽  
Oestrous Cycle ◽  
Female Rats ◽  
Ovariectomized Rats ◽  
Normal Female ◽  
Female Rat ◽  
Thermal Lesions ◽  
Gonadotrophin Secretion

Thermal lesions were placed in the subcommissural organ (SCO) of female rats with normal cycles and long-term ovariectomized rats. In normal female rats SCO lesions disrupted the oestrous cycle in more than half of the animals, the majority of which entered a state of prolonged dioestrus. In these animals, serum gonadotrophin levels were similar to those of rats with regular cycles on day 2 of dioestrus. In animals in which the oestrous cycle was maintained, a delayed LH surge occurred on the day of pro-oestrus and the pro-oestrous FSH surge was absent. The usual increase in FSH on the day of oestrus was present. Lesions in the SCO did not change the high gonadotrophin levels typical of ovariectomized animals. These results suggested that the SCO may play a role in the control of the cyclic but not the tonic release of the gonadotrophins. In particular, it appears that the SCO might be involved in the regulation of the hypersecretion of FSH during the day of pro-oestrus.

Pulsatile prolactin secretory patterns throughout the oestrous cycle in the rat

1993 ◽  
Vol 137 (1) ◽  
pp. 43-47 ◽  
Author(s):  
A. Lafuente ◽  
J. Marcó ◽  
A. I. Esquifino
Keyword(s):  
Adult Female ◽  
Prolactin Secretion ◽  
Oestrous Cycle ◽  
Relative Amplitude ◽  
Female Rat ◽  
Mean Values ◽  
Low Level ◽  
Absolute Amplitude ◽  
The Absolute

ABSTRACT Prolactin secretion throughout the oestrous cycle in the rat remains at a low level and fairly constant, with the exception of the surge at pro-oestrus. The present study was designed to characterize possible changes in pulsatile patterns of prolactin during the oestrous cycle of the adult female rat. Mean values of prolactin increased from dioestrus-2 to pro-oestrus and then decreased to the values found at dioestrus-1. The number of peaks remained fairly constant in any phase of the oestrous cycle. The absolute amplitude of the peaks increased numerically but was not statistically significant from dioestrus-2 to pro-oestrus then decreasing until dioestrus-1. No changes in the relative amplitude or duration of the peaks throughout the oestrous cycle were detected. The results indicated that there is a similar pulsatile pattern of prolactin at any stage of the oestrous cycle, when samples were obtained during the morning. Journal of Endocrinology (1993) 137, 43–47

P.5.097 Effect of lamictal on EEG paroxysmal activity of the female rat brain in different stages of the oestrous cycle

2005 ◽  
Vol 15 ◽  
pp. S256-S256
Author(s):  
F.K. Rider ◽  
T.A. Voronina ◽  
G.N. Avakian ◽  
S.G. Burd ◽  
L.N. Nerobkova ◽  
...  
Keyword(s):  
Rat Brain ◽  
Oestrous Cycle ◽  
Female Rat ◽  
Paroxysmal Activity

Localization of central nervous system structures mediating extracellular thirst in the female rat

1984 ◽  
Vol 100 (2) ◽  
pp. 183-NP ◽  
Author(s):  
J. Kucharczyk
Keyword(s):  
Angiotensin Ii ◽  
Water Intake ◽  
Extracellular Fluid ◽  
Oestrous Cycle ◽  
Female Rats ◽  
Female Rat ◽  
Adrenergic Agonist ◽  
Preoptic Region ◽  
Body Fluid Compartments ◽  
Fluid Compartments

ABSTRACT Water intake elicited by microinjection of the hormone angiotensin-II into the preoptic region of cyclic female rats was significantly less on days of vaginal oestrus than at dioestrus or metoestrus, whereas the drinking of 2·7% NaCl solution, to which rats also had access, did not vary with the cycle. Administration of the same dose of angiotensin-II to the subfornical organ and the lateral cerebral ventricles induced drinking at all stages of the oestrous cycle, but the volumes of water or 2·7% NaCl ingested did not vary with the cycle. Water intake after subcutaneous injection of isoprenaline, a β-adrenergic agonist which causes increased angiotensin biosynthesis, varied cyclically with the stage of the oestrous cycle. On the other hand, water and 2·7% NaCl intakes induced by intraperitoneal injection of hypertonic NaCl (a cellular stimulus of thirst) or by 24-h water deprivation (which dehydrates both the extracellular and cellular body fluid compartments) did not differ significantly at the various stages of the oestrous cycle. The finding that fluctuations in angiotensin- and isoprenaline-induced water intake parallel the changes in spontaneous 24-h drinking suggests that the preoptic region may play an important role in the maintenance of extracellular fluid balance in synchrony with the oestrous cycle. J. Endocr. (1984) 100, 183–188

CYCLIC VARIATIONS IN THE HYPOPHYSEAL FSH-CONTENT IN THE FEMALE RAT

1964 ◽  
Vol 45 (3) ◽  
pp. 335-339 ◽  
Author(s):  
E. Gans ◽  
S. E. de Jongh ◽  
G. P. van Rees ◽  
J. J. van der Werff ten Bosch ◽  
O. L. Wolthuis
Keyword(s):  
Anterior Pituitary ◽  
Oestrous Cycle ◽  
Experimental Series ◽  
Female Rat ◽  
Pituitary Glands ◽  
Cyclic Variations

ABSTRACT FSH-estimations were carried out on anterior pituitary glands obtained from rats in four stages of the oestrous cycle: early dioestrus, late dioestrus, pro-oestrus and oestrus. Autopsy was carried out in one experimental series in the morning, in a second one in the afternoon. The combined results suggested a sudden fall in hypophyseal FSH-content about noon on the day of pro-oestrus. This suggestion was confirmed by estimating the FSH-content of anterior pituitary glands removed from pro-oestrous rats either in the morning or in the afternoon.

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