ALTERATION IN THE OESTROUS CYCLE LENGTH AFTER PITUITARY HOMOTRANSPLANTATION IN THE GUINEA-PIG

1970 ◽  
Vol 48 (2) ◽  
pp. 277-283
Author(s):  
R. M. DAS ◽  
G. K. BENSON
Keyword(s):  
Guinea Pig ◽  
Adult Female ◽  
Guinea Pigs ◽  
Cycle Length ◽  
Oestrous Cycle ◽  
Kidney Capsule ◽  
Graft Tissue

SUMMARY Pituitaries from adult or young guinea-pigs were implanted under the kidney capsule of intact adult female guinea-pigs between the 3rd and 5th days of the oestrous cycle. The oestrous cycles in the recipients of adult pituitaries were mostly normal in length. Seven out of nine animals engrafted with pituitaries from their own litters had a prolonged dioestrus, ranging from 8 to 16 days longer than normal, at the end of which oestrus and ovulation occurred. When the grafts contained pituitaries from one male and one female pup the cycle extension was more pronounced than when they were composed of pituitaries from two or three female pups. The occurrence of prolonged dioestrus accompanied by a delayed ovulation in the graft-bearing animals is suggested to be associated with the production of luteotrophic hormone by the graft tissue, possibly deriving from basophil cells.

PRODUCTION OF PROSTAGLANDINS BY THE GUINEA-PIG UTERUS

1972 ◽  
Vol 54 (1) ◽  
pp. 147-159 ◽  
Author(s):  
N. L. POYSER
Keyword(s):  
Guinea Pig ◽  
Guinea Pigs ◽  
Oestrous Cycle ◽  
Prostaglandin E ◽  
Prostaglandin F

SUMMARY The production of prostaglandins by the uterus and the resting levels of prostaglandins in the uterus on selected days of the oestrous cycle were determined in guinea-pigs. Prostaglandin F2α was detectable in the guinea-pig uterus in small amounts on days 13, 14 and 15 of the cycle. Prostaglandin E2 was present in even smaller amounts on days 14 and 15. The homogenized guinea-pig uterus had the ability to biosynthesize prostaglandins, from endogenous precursors, during incubation on every day of the cycle studied. Four to six times more prostaglandin F2α than E2 was produced on any one day with the amounts of prostaglandins formed increasing towards the end of the oestrous cycle. Indomethacin inhibited the biosynthesis of prostaglandins by the guinea-pig uterus. The implications of these findings are discussed.

HYSTERECTOMY OF THE NEWBORN GUINEA-PIG, SUBSEQUENT EFFECTS ON THE OESTROUS CYCLE AND LIFE SPAN OF THE CORPORA LUTEA

1975 ◽  
Vol 66 (2) ◽  
pp. 233-237 ◽  
Author(s):  
W. BUÑO ◽  
E. CARLEVARO ◽  
L. RIBONI ◽  
H. D'ALBORA ◽  
L. DE LOS REYES ◽  
...  
Keyword(s):  
Guinea Pig ◽  
Life Span ◽  
Guinea Pigs ◽  
Adult Life ◽  
Oestrous Cycle ◽  
Corpora Lutea ◽  
Long Cycles

SUMMARY Longer oestrous cycles result from neonatal hysterectomy than from hysterectomy in adult life. Section and cauterization of the utero-vaginal union also prolonged the vaginal closure period up to an average of 55 days. The destruction of the mesometrium did not lengthen the oestrous cycle. Uterine autografts in hysterectomized newborn guinea-pigs did not prevent the long cycles.

THE EFFECT OF AUTOTRANSPLANTATION OF THE OVARIES TO THE KIDNEYS OR UTERUS ON THE OESTROUS CYCLE OF THE GUINEA-PIG

1968 ◽  
Vol 41 (1) ◽  
pp. 95-103 ◽  
Author(s):  
K. P. BLAND ◽  
B. T. DONOVAN
Keyword(s):  
Guinea Pig ◽  
Functional State ◽  
Guinea Pigs ◽  
Follicular Development ◽  
Oestrous Cycle ◽  
Corpora Lutea ◽  
Primordial Follicles ◽  
Local Nature

SUMMARY Autotransplantation of the ovaries of guinea-pigs to either the uterus or the kidneys caused the degeneration of all luteal and follicular tissue with the exception of the primordial follicles situated in the periphery of the graft. Follicular development then took place and oestrus and ovulation occurred 10–11 days after transplantation. The corpora lutea formed at this ovulation were maintained in a functional state for more than 35 days when the ovaries were transferred to the kidneys but when ovarian grafts were made to the uterus a series of shortened vaginal cycles was observed. These results substantiate the local nature of the luteolytic abilities of the uterus in this species and imply the existence of a uterine luteolytic substance.

THE EFFECT OF HYPOPHYSIAL STALK-SECTION ON THE CORPUS LUTEUM OF THE GUINEA-PIG

1971 ◽  
Vol 50 (4) ◽  
pp. 625-635 ◽  
Author(s):  
DOREEN V. ILLINGWORTH ◽  
J. S. PERRY
Keyword(s):  
Growth Rate ◽  
Guinea Pig ◽  
Corpus Luteum ◽  
Guinea Pigs ◽  
Oestrous Cycle ◽  
Corpora Lutea ◽  
Normal Cycle ◽  
Luteal Regression ◽  
Normal Regression ◽  
And Function

SUMMARY The effects of hypophysial stalk-section on the growth and function of the corpus luteum of the non-pregnant guinea-pig have been compared with the effects of hypophysectomy (as previously described) and with the effects of prolactin administered to hypophysectomized animals. Stalk-section soon after ovulation did not impair the growth of the corpora lutea nor their ability to secrete progesterone. Stalk-section before day 9 of the oestrous cycle prevented the normal regression of the corpora lutea; they continued to grow and 3 weeks after ovulation were as large as those of pregnant animals, or of non-pregnant hysterectomized guinea-pigs. The corpora lutea regressed irregularly during the following 2 weeks. When performed on, or later than day 9, stalk-section did not prevent luteal regression at the normal time. Administration of prolactin (10 i.u./day) to hypophysectomized guinea-pigs restored the growth-rate of the corpora lutea, which reached sizes comparable to those of the normal cycle, and those of stalk-sectioned animals, by 10 days after ovulation. Our results indicate that prolactin can have substantial luteotrophic activity in the guinea-pig.

Mast cells and Kurloff cells - Their detection throughout the oestrous cycle in normal guinea pig ovaries and in guinea pigs with cystic rete ovarii

2021 ◽  
Vol 136 ◽  
pp. 512-518
Author(s):  
Pavla Hamouzova ◽  
Petr Cizek ◽  
Vladimir Jekl ◽  
Karolina Gozdziewska-Harlajczuk ◽  
Joanna Kleckowska-Nawrot
Keyword(s):  
Mast Cells ◽  
Guinea Pig ◽  
Guinea Pigs ◽  
Oestrous Cycle

OESTROGEN AND PROGESTERONE AND THE FUNCTION OF THE CORPORA LUTEA IN THE GUINEA-PIG

1970 ◽  
Vol 47 (2) ◽  
pp. 225-230 ◽  
Author(s):  
K. P. BLAND ◽  
B. T. DONOVAN
Keyword(s):  
Guinea Pig ◽  
Guinea Pigs ◽  
Single Injection ◽  
Glass Beads ◽  
Oestrous Cycle ◽  
Corpora Lutea ◽  
Luteal Regression ◽  
Oestradiol Benzoate

SUMMARY Regression of the corpora lutea in the guinea-pig could be accelerated by treatment with 10 μg. oestradiol benzoate daily over days 3–11 of the oestrous cycle. A single injection of 10 μg. oestradiol benzoate on day 3 was also effective. The luteolytic effect of oestrogen was abolished by hysterectomy, indicating that the uterus is involved in the mediation of the response. Progesterone (5 mg. daily over days 3–11) enhanced the luteal regression brought about by the presence of two glass beads in one horn of the uterus, but did not affect luteal size in otherwise intact females. Treatment of guinea-pigs with 5 mg. progesterone daily over days 2–5 or 4–7 failed to alter the length of the oestrous cycle.

INFLUENCE OF SEX AND AGE ON THE CORTISOL CONTENT OF PERIPHERAL TISSUES AND ADRENAL GLANDS IN THE GUINEA-PIG

1974 ◽  
Vol 61 (2) ◽  
pp. 273-276 ◽  
Author(s):  
A. T. A. FAZEKAS ◽  
J. HOMOKI ◽  
W. M. TELLER
Keyword(s):  
Guinea Pig ◽  
Brain Stem ◽  
Adult Female ◽  
Cortisol Level ◽  
Guinea Pigs ◽  
Adrenal Glands ◽  
Peripheral Tissues ◽  
Significant Difference ◽  
Different Tissues ◽  
Age And Sex

SUMMARY The influence of age and sex on the cortisol content of adrenals, liver, kidney, lung, heart, spleen, muscle, cerebrum, brain stem and blood was studied in white guinea-pigs. In prepuberal animals no significant difference between sexes was found in the cortisol content of different tissues. In adult female animals, the blood cortisol level was significantly higher than in the male animals. Significantly more cortisol was found in kidneys of adult male than of female animals. In adult guinea-pigs, the cortisol content was lower in every tissue examined, except liver, compared with young animals. These differences were highly significant. In female guinea-pigs the decrease in tissue cortisol content with age was more pronounced than in male animals.

SOME OBSERVATIONS ON THE EXCRETION OF 17-KETOSTEROIDS AND 17-KETOGENIC STEROIDS BY GUINEA-PIGS

1960 ◽  
Vol 20 (1) ◽  
pp. 24-35 ◽  
Author(s):  
R. V. BROOKS ◽  
BARBARA E. CLAYTON ◽  
JOYCE E. HAMMANT
Keyword(s):  
Guinea Pig ◽  
Urinary Excretion ◽  
Guinea Pigs ◽  
Oestrous Cycle ◽  
Pregnant Mother ◽  
Cyclical Change ◽  
Urinary Steroids ◽  
Adrenalectomized Animal ◽  
Consistent Trend

SUMMARY 1. 17-Ketosteroids (KS) and 17-ketogenic steroids (KG) may be determined in guinea-pig urine by the method of Norymberski, Stubbs & West [1953]. Studies on the fractionation of urinary steroids showed the method was applicable to the urine of pregnant guinea-pigs. 2. So little material in the faeces of guinea-pigs behaved as KS that excretion by this route may be ignored. 3. Daily vaginal lavages shortened the oestrous cycle in the guinea-pig and abolished the peak of KS excretion seen at oestrus in normal cycles. No consistent trend in the excretion of KG was seen during normal oestrous cycles. No cyclical change in KS excretion was seen after ovariectomy. 4. During pregnancy in the guinea-pig, there was a rise in the excretion of KG and KS. The increase was not abolished by ovariectomy. The rise did not occur in one adrenalectomized animal which went to term, though it continued to excrete significant amounts of KS. The contribution of the foetal adrenals to the excretion of steroids by the pregnant mother was probably small. 5. Non-specific adrenal stimulation caused a rise in the urinary excretion of KS and KG. 6. Fractionation of the KS released from the urine of an intact non-pregnant guinea-pig by a mild hydrolytic procedure gave five major compounds, one in the 11-deoxy and four in the 11-oxy fraction. All five compounds were excreted in increased amounts by a pregnant intact and by a pregnant adrenalectomized guinea-pig.

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