Circulating levels of inhibin and FSH during the oestrous cycle in 4 genotypes of sheep with different reproductive performances

1998 ◽  
Vol 29 (2) ◽  
pp. 213-224
Author(s):  
D Vanmontfort ◽  
R Peeters ◽  
N Buys ◽  
L Rombauts ◽  
G Verhoeven ◽  
...  
Keyword(s):  
Oestrous Cycle ◽  
Circulating Levels

Odour recognition by male hamsters: discrimination of the hormonal state of females by odour from vaginal secretions

1985 ◽  
Vol 105 (2) ◽  
pp. 255-262 ◽  
Author(s):  
E. Steel
Keyword(s):  
Scent Marking ◽  
Oestrous Cycle ◽  
Vaginal Secretion ◽  
Vaginal Secretions ◽  
Marking Behaviour ◽  
Circulating Levels

ABSTRACT Male hamsters were tested for their interest in females on different days of the oestrous cycle. Behaviour of males towards novel females was measured and (after exposure to vaginal secretion) towards females that matched or did not match that vaginal odour. Because pro-oestrous (day 4) females lay trails of vaginal secretion and will become receptive within a few hours, it was predicted that males would show more interest in day 4 than in other dioestrous females. While males showed no preference for novel, pro-oestrous females over dioestrous females, after pre-exposure to odour, their response to females was determined by the cycle day of the vaginal secretion to which they had been exposed. Males pre-exposed to vaginal odour from females carrying large implants of oestrogen preferred to spend more time with females who matched that vaginal odour than mismatching females and to sniff them more. This preference was not seen if the females carried small oestrogen implants or had no replacement oestrogen. This suggests that pro-oestrous females (who are known to have high circulating levels of oestrogen) can, by means of their scent-marking behaviour, attract and keep males nearby until they become receptive. J. Endocr. (1985) 105, 255–262

scholarly journals Modulation of the renin–angiotensin–aldosterone system by steroid hormones during the oestrous cycle in mares

2020 ◽  
Vol 68 (1) ◽  
pp. 79-84
Author(s):  
Katy Satué ◽  
Paloma Montesinos ◽  
Ana MuÑoz
Keyword(s):  
Steroid Hormones ◽  
Oestrous Cycle ◽  
Laboratory Animals ◽  
Mineralocorticoid Receptors ◽  
Renin Angiotensin Aldosterone System ◽  
Renin Angiotensin ◽  
Positive Correlations ◽  
Relationship Of ◽  
The Relationship ◽  
Circulating Levels

AbstractIn women and females of different species of laboratory animals, oestrogens stimulate the renin–angiotensin–aldosterone system (RAAS) by increasing tissue and circulating levels of angiotensinogen and renin during the preovulatory period. Progesterone and cortisol compete with aldosterone for mineralocorticoid receptors, which results in increased Na+ reabsorption during the postovulatory period. The purpose of the current research was to analyse the relationship of oestradiol-17β, progesterone and cortisol with RAAS in 23 mares during an oestrous cycle. During the preovulatory period, significant positive correlations of oestradiol-17β with renin and aldosterone concentrations and negative correlations of progesterone with renin and aldosterone concentrations were found. In contrast, during the postovulatory period, oestradiol-17β concentrations were positively correlated with angiotensin concentrations and progesterone was negatively correlated with this component of the RAAS. Cortisol concentrations were not correlated with the hormones of the RAAS, neither before nor after ovulation. This research demonstrates that, as occurs in other species, changes in the RAAS during the periovulatory period in mares may be modulated by variations in the concentrations of steroid hormones.

PERIPHERAL PLASMA PROGESTERONE DURING PREGNANCY AND THE OESTROUS CYCLE IN THE TAMMAR WALLABY, MACROPUS EUGENII

1972 ◽  
Vol 55 (1) ◽  
pp. 63-71 ◽  
Author(s):  
MEREDITH LEMON
Keyword(s):  
Mammalian Species ◽  
Tammar Wallaby ◽  
Oestrous Cycle ◽  
Plasma Progesterone ◽  
Common Assumption ◽  
Macropus Eugenii ◽  
Peripheral Plasma ◽  
Competitive Protein Binding ◽  
The Common ◽  
Circulating Levels

SUMMARY Progesterone or progestin concentrations were measured in the peripheral plasma of the tammar wallaby (Macropus eugenii) during pregnancy and the oestrous cycle, using a competitive protein-binding method. In common with most other members of the marsupial family Macropodidae, the tammar has a gestation period slightly shorter than one oestrous cycle, and the occurrence of pregnancy does not affect the time of onset of the following oestrus. This study was an attempt to obtain direct evidence for the common assumption that most macropodid marsupials secrete the same amounts of ovarian hormones during pregnancy as they do during the oestrous cycle. The effect on progesterone levels of ovariectomy and removal of the corpus luteum was also studied to discover whether an extra-ovarian source of progesterone exists during pregnancy. Circulating levels of both total plasma progestins and progesterone are very low compared with other mammalian species—less than 1 ng/ml at all stages of the reproductive cycle. An increase in plasma progesterone concentration, apparently of ovarian origin, occurs before birth and/or oestrus, and this may possibly be associated with parturition. The plasma progestin concentration during pregnancy, and that of progesterone during the last 10 days of pregnancy, were significantly greater than during the oestrous cycle.

Direct ovarian - uterine transfer of progesterone increases embryo survival in gilts

2011 ◽  
Vol 23 (7) ◽  
pp. 921 ◽  
Author(s):  
R. Z. Athorn ◽  
P. Stott ◽  
E. G. Bouwman ◽  
R. Ashman ◽  
S. O'Leary ◽  
...  
Keyword(s):  
Uterine Horn ◽  
Oestrous Cycle ◽  
The Other ◽  
Embryo Survival ◽  
Unilateral Ovariectomy ◽  
Maintenance Requirement ◽  
Local Supply ◽  
The Difference ◽  
Circulating Levels ◽  
Post Implantation

This study employed a unilateral ovariectomy model to investigate the relevance of the local supply of progesterone (ovary) compared with the systemic supply of progesterone, in terms of embryo survival in the ipsilateral uterine horn as opposed to the contralateral uterine horn. Thirty gilts were unilaterally ovariectomised (ULO) during the luteal stage of their first oestrous cycle. Half of the ULO gilts were fed at 1.2 maintenance requirement (M), while the other half were fed at 2.4 M. Across ULO gilts 0.8 more embryos survived in the ipsilateral horn compared with the contralateral horn at Day 35 of gestation (P < 0.05). In ULO gilts on the 2.4 M feed level the difference (+1.3; P < 0.05) between the ipsi- and contralateral horn was more pronounced than on the 1.2 M feed level (+0.4; NS). The higher feed level reduced circulating levels of systemic progesterone on Day 5 of pregnancy but not embryo survival at Day 35. However, post-implantation embryo survival was lower on the low feed level. In conclusion, these data indicate that local progesterone supply from the ovaries to the uterus contributes to the probability of embryo survival.

Elevated Tissue Factor and Tissue Factor Pathway Inhibitor Circulating Levels in Ischaemic Heart Disease Patients

1998 ◽  
Vol 79 (03) ◽  
pp. 495-499 ◽  
Author(s):  
Anna Maria Gori ◽  
Sandra Fedi ◽  
Ludia Chiarugi ◽  
Ignazio Simonetti ◽  
Roberto Piero Dabizzi ◽  
...  
Keyword(s):  
Heart Disease ◽  
Ischaemic Heart Disease ◽  
Tissue Factor ◽  
Plasma Levels ◽  
Tissue Factor Pathway Inhibitor ◽  
Common Source ◽  
Previous Myocardial Infarction ◽  
Control Subjects ◽  
Tissue Factor Pathway ◽  
Circulating Levels

SummarySeveral studies have shown that thrombosis and inflammation play an important role in the pathogenesis of Ischaemic Heart Disease (IHD). In particular, Tissue Factor (TF) is responsible for the thrombogenicity of the atherosclerotic plaque and plays a key role in triggering thrombin generation. The aim of this study was to evaluate the TF/Tissue Factor Pathway Inhibitor (TFPI) system in patients with IHD.We have studied 55 patients with IHD and not on heparin [18 with unstable angina (UA), 24 with effort angina (EA) and 13 with previous myocardial infarction (MI)] and 48 sex- and age-matched healthy volunteers, by measuring plasma levels of TF, TFPI, Prothrombin Fragment 1-2 (F1+2), and Thrombin Antithrombin Complexes (TAT).TF plasma levels in IHD patients (median 215.4 pg/ml; range 72.6 to 834.3 pg/ml) were significantly (p<0.001) higher than those found in control subjects (median 142.5 pg/ml; range 28.0-255.3 pg/ml).Similarly, TFPI plasma levels in IHD patients were significantly higher (median 129.0 ng/ml; range 30.3-316.8 ng/ml; p <0.001) than those found in control subjects (median 60.4 ng/ml; range 20.8-151.3 ng/ml). UA patients showed higher amounts of TF and TFPI plasma levels (TF median 255.6 pg/ml; range 148.8-834.3 pg/ml; TFPI median 137.7 ng/ml; range 38.3-316.8 ng/ml) than patients with EA (TF median 182.0 pg/ml; range 72.6-380.0 pg/ml; TFPI median 115.2 ng/ml; range 47.0-196.8 ng/ml) and MI (TF median 213.9 pg/ml; range 125.0 to 341.9 pg/ml; TFPI median 130.5 ng/ml; range 94.0-207.8 ng/ml). Similar levels of TF and TFPI were found in patients with mono- or bivasal coronary lesions. A positive correlation was observed between TF and TFPI plasma levels (r = 0.57, p <0.001). Excess thrombin formation in patients with IHD was documented by TAT (median 5.2 μg/l; range 1.7-21.0 μg/l) and F1+2 levels (median 1.4 nmol/l; range 0.6 to 6.2 nmol/l) both significantly higher (p <0.001) than those found in control subjects (TAT median 2.3 μg/l; range 1.4-4.2 μg/l; F1+2 median 0.7 nmol/l; range 0.3-1.3 nmol/l).As in other conditions associated with cell-mediated clotting activation (cancer and DIC), also in IHD high levels of circulating TF are present. Endothelial cells and monocytes are the possible common source of TF and TFPI. The blood clotting activation observed in these patients may be related to elevated TF circulating levels not sufficiently inhibited by the elevated TFPI plasma levels present.

The Pathogenesis of Thrombotic Thrombocytopenic Purpura

1979 ◽  
Author(s):  
H. C. Kwaan
Keyword(s):  
Plasminogen Activator ◽  
Thrombotic Thrombocytopenic Purpura ◽  
Degradation Products ◽  
Vascular Lesions ◽  
Local Defect ◽  
Laboratory Findings ◽  
Thrombocytopenic Purpura ◽  
Fibrin Degradation Products ◽  
Severity Of The Disease ◽  
Circulating Levels

The vascular lesions with microthrombi were studied in 12 patients with thrombotic thrombocytopenic purpura (TTP), diagnosed by the characteristic clinical and laboratory findings and confirmed histologically in each case. While defibrination was not observed, and with only minimal changes in the circulating levels of fibrinogen, fibrin degradation products and plasminogen activator, the microthrombotic lesion was invariably present. Immunofluorescent and histochemical studies indicated that both platelet and fibrin were present in the microthrombi with the platelet components dominant in many cases. Using the fibrin slide method, plasminogen activator was demonstrated in the uninvolved blood vessels but totally absent in the vessels occluded by microthrombi. in contrast, fibrinolysis is always present in the vessels afflicted with other types of thrombosis, such as the microthrombi in disseminated intravascular coagulation. Since circulating fibrinolytic activity was normal in TTP, the absence of vascular fibrinolysis is a local defect due to either inhibition by the platelet deposits or by local vascular damage. The inability of thrombolysis may explain the absence of systemic defibrination and the severity of the disease.

NEW DATA CONCERNING THE ROLE PLAYED BY PROGESTERONE IN THE CONTROL OF FOLLICULAR GROWTH IN THE RAT

1974 ◽  
Vol 75 (3) ◽  
pp. 569-578 ◽  
Author(s):  
G. Buffler ◽  
S. Roser
Keyword(s):  
Wistar Rats ◽  
Venous Blood ◽  
Oestrous Cycle ◽  
Female Rats ◽  
Cycle Duration ◽  
Follicular Growth ◽  
The Third ◽  
Female Wistar Rats

ABSTRACT The mechanisms involved in the prolongation of the oestrous cycle following LH administration were studied in 4-day cyclic female Wistar rats. In females injected with LH on the morning of dioestrus I there was an increase in ovarian venous blood progesterone as compared with non-injected animals. In both LH-treated females, and those injected with progesterone on the morning of dioestrus I, a slowing up in follicular growth was observed from the afternoon of dioestrus I. The size of follicles greater than 400 urn present in LH or progesterone injected animals on the third day of cycle was similar to the size reached by the same range of follicles in non-injected animals on the second day of the cycle. Hence, the increase in endogenous ovarian progesterone elicited by LH was considered as the cause of the slowing up of follicular growth and therefore of the lengthening of the oestrous cycle duration in female rats injected with LH at the beginning of 4-day cycle.

FSH AND LH LEVELS IN THE INTACT AND UNILATERALLY OVARIECTOMIZED CYCLING RAT

1972 ◽  
Vol 69 (2) ◽  
pp. 267-280 ◽  
Author(s):  
Richard D. Peppler
Keyword(s):  
Plasma Concentrations ◽  
Follicular Development ◽  
Slight Modification ◽  
Oestrous Cycle ◽  
Successive Cycle ◽  
Unilateral Ovariectomy ◽  
Subsequent Cycle ◽  
Intact Rats

ABSTRACT Intact 5-day cycling rats were killed between 8–10 a. m. on each day of the oestrous cycle; experimental rats were unilaterally ovariectomized (ULO) at 9 a. m. on day 1 (oestrus) and killed between 8 and 10 a. m. on days 2, 3, 4 or 1 of the subsequent cycle. Pituitary and plasma concentrations of FSH and LH were measured in both groups of rats. Pituitary FSH concentration was measured by the Steelman-Pohley method with slight modification; plasma FSH by the Igarashi-McCann assay and pituitary and plasma LH concentration by the OAAD method. In intact rats, pituitary FSH values remained constant for the first three days of the cycle, increased on day 4 and reverted to early cycle values by day 5. Plasma FSH increased between days 2 and 3 and days 5 and 1. Pituitary LH concentration remained the same for days 1 and 2; increased two-fold on days 3 and 4, and increased further by day 5. Plasma LH increased between days 2 and 3; other differences between successive cycle days were not apparent. Following ULO on day 1, pituitary FSH increased steadily, but not significantly, for the remaining cycle. Plasma FSH did not change from day 2 through day 1 of the subsequent cycle. Pituitary LH remained low on day 2, increased sharply by day 3 and decreased (50 %) by day 4. Plasma LH also increased between days 2 and 3. Other differences between successive days following unilateral ovariectomy on day 1 were not apparent. Correlation of gonadotrophin activity with follicular development suggests that the mechanism of compensatory ovulation in the rat may be one of an increase in time of exposure to a constant gonadotrophic level for the duration of the oestrous cycle rather than to increased levels of the gonadotrophin.

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