Dynamics of ovarian inhibin secretion during the oestrous cycle of the rat

1990 ◽  
Vol 126 (1) ◽  
pp. 151-157 ◽  
Author(s):  
G. Watanabe ◽  
K. Taya ◽  
S. Sasamoto
Keyword(s):  
Plasma Levels ◽  
Inverse Relationship ◽  
Plasma Concentrations ◽  
Oestrous Cycle ◽  
Significant Inverse Relationship ◽  
Follicular Maturation ◽  
Final Maturation ◽  
Ovarian Inhibin ◽  
Selection Of

ABSTRACT Plasma and ovarian concentrations of inhibin were determined at 3-h intervals throughout the 4-day oestrous cycle of rats by a radioimmunoassay (RIA) based on a bovine RIA. Plasma concentrations of LH, FSH, progesterone, testosterone, oestradiol-17β, and pituitary contents of FSH and LH were also determined during the cycle. Plasma levels of inhibin showed a marked increase on the morning of oestrus and the afternoon of metoestrus, and a further increase was noted on the morning of pro-oestrus. These increases in plasma levels of inhibin were probably due to the following three events in the ovary, follicular recruitment on the morning of oestrus, selection of follicles on the day of metoestrus, and final maturation of follicles for ovulation on the morning of pro-oestrus with an increase in oestradiol-17β secretion. A striking decrease in inhibin secretion occurred during the process of ovulation after the preovulatory gonadotrophin surge on the afternoon of pro-oestrus. Basal levels of plasma FSH gradually decreased from metoestrus to pro-oestrus as plasma levels of inhibin increased. There was a significant inverse relationship between plasma levels of FSH and inhibin throughout the oestrous cycle (r = −0·51). The present findings suggest that changes in the plasma levels of inhibin during the oestrous cycle provide a precise indicator for follicular recruitment, selection and ovulation, and that changes in concentrations of oestradiol-17β in the plasma are associated with follicular maturation. Journal of Endocrinology (1990) 126, 151–157

Follicular dynamics and secretion of inhibin and oestradiol-17β during the oestrous cycle of the hamster

1995 ◽  
Vol 146 (1) ◽  
pp. 169-176 ◽  
Author(s):  
H Kishi ◽  
K Taya ◽  
G Watanabe ◽  
S Sasamoto
Keyword(s):  
Plasma Levels ◽  
Marked Decrease ◽  
Plasma Concentrations ◽  
Follicular Development ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Oestrous Cycle ◽  
Antral Follicles ◽  
Follicular Maturation ◽  
Follicular Dynamics

Abstract Plasma and ovarian levels of inhibin were determined by a radioimmunoassay (RIA) at 3-h intervals throughout the 4-day oestrous cycle of hamsters. Plasma concentrations of FSH, LH, progesterone, testosterone and oestradiol-17β were also determined by RIAs. In addition, hamsters were injected at various times with human chorionic gonadotrophin (hCG) to determine the follicular development. The changes in plasma concentrations of FSH after injection of antisera to oestradiol-17β (oestradiol-AS) and inhibin (inhibin-AS) on the morning of day 2 (day 1=day of ovulation) were also determined. Plasma concentrations of inhibin showed a marked increase on the afternoon of day 1, remained at plateau levels until the morning of day 4, then increased abruptly on the afternoon of day 4 when preovulatory LH and FSH surges were initiated. A marked decrease in plasma concentrations of inhibin occurred during the process of ovulation after the preovulatory gonadotrophin surges. An inverse relationship between plasma levels of FSH and inhibin was observed when the secondary surge of FSH was in progress during the periovulatory period. Plasma concentrations of oestradiol-17β showed three increase phases and these changes differed from those of inhibin. Changes in plasma concentrations of oestradiol-17β correlated well with the maturation and regression of large antral follicles. Follicles capable of ovulating following hCG administration were first noted at 2300 h on day 1. The number of follicles capable of ovulating reached a maximum on the morning of day 3 (24·8± 0·6), and decreased by 0500 h on day 4 (15·0 ± 1·1), corresponding to the number of normal spontaneous ovulations. Plasma concentrations of FSH were dramatically increased within 6 h after inhibin-AS, though no increase in FSH levels was observed after oestradiol-AS. These findings suggest that changes in the plasma levels of inhibin during the oestrous cycle provide a precise indicator of follicular recruitment, and that the changes in plasma concentrations of oestradiol-17β are associated with follicular maturation. These findings also suggest that inhibin may play a major role in the inhibition of FSH secretion during the oestrous cycle of the hamster. Journal of Endocrinology (1995) 146, 169–176

PROLONGED RELEASE BY DIOESTROUS RATS OF FOLLICLE-STIMULATING HORMONE DURING THE PERIOD OF OVULATION INDUCED BY LUTEINIZING HORMONE RELEASING HORMONE

1979 ◽  
Vol 81 (1) ◽  
pp. 109-118 ◽  
Author(s):  
SHUJI SASAMOTO ◽  
SHIGEO HARADA ◽  
KAZUYOSHI TAYA
Keyword(s):  
Luteinizing Hormone ◽  
Plasma Concentrations ◽  
High Plasma ◽  
Oestrous Cycle ◽  
Prolonged Release ◽  
Luteinizing Hormone Releasing Hormone ◽  
Releasing Hormone ◽  
Follicular Maturation ◽  
Lh Rh ◽  
Premature Ovulation

When 1·0 μg luteinizing hormone releasing hormone (LH-RH) was given i.v. three times at 1 h intervals from 17.00 to 19.00 h on the day of dioestrus (day 0) to regular 4 day cyclic rats, premature ovulation was induced the next morning (day 1) with the number of ova present comparable to normal spontaneous ovulation. The next spontaneous ovulation occurred on the morning of day 5, 4 days after premature ovulation induced by LH-RH. Plasma concentrations of FSH and LH showed transient rises and falls within 1 h of administration of LH-RH; concentrations of FSH in the plasma decreased from 20.00 h on day 0 but markedly increased again from 23.00 h on day 0 to 02.00 h on day 1 and these high levels persisted until 14.00 h on day 1, with only a small increase of plasma LH during this period. The duration of increased FSH release during premature ovulation induced by LH-RH treatment was 6 h longer than the FSH surge occurring after administration of HCG on day 0. Surges of gonadotrophin were absent on the afternoon of day 1 (the expected day of pro-oestrus) and the surges characteristic of pro-oestrus occurred on the afternoon of day 4 and ovulation followed the next morning. The pituitary content of FSH did not decrease despite persisting high plasma levels of FSH during premature ovulation induced by either LH-RH or HCG on day 0. The changes in uterine weight indicated that the pattern of oestrogen secretion from the day of premature ovulation induced by LH-RH to the day of the next spontaneous ovulation was similar to that of the normal 4 day oestrous cycle. When 10 i.u. HCG were given on day 0, an increase in oestrogen secretion occurred on day 2, 1 day earlier than in the group given LH-RH on day 0. This advancement of oestrogen secretion was assumed to be responsible for the gonadotrophin surges on day 3. Similar numbers of fully developed follicles were found by 17.00 h on day 2 after premature ovulation induced by either LH-RH or HCG, suggesting that the shorter surge of FSH during premature ovulation induced by HCG had no serious consequences on the initiation of follicular maturation for the succeeding oestrous cycle in these rats. Administration of LH-RH on day 0 had no direct effect on the FSH surge during premature ovulation. Secretory changes in the ovary during ovulation may be responsible for this prolonged selective release of FSH.

INITIATION OF FOLLICULAR MATURATION AND OVULATION AFTER REMOVAL OF THE LITTER FROM THE LACTATING RAT

1980 ◽  
Vol 87 (3) ◽  
pp. 393-400 ◽  
Author(s):  
KAZUYOSHI TAYA ◽  
SHUJI SASAMOTO
Keyword(s):  
Plasma Levels ◽  
Plasma Concentrations ◽  
Follicular Development ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Moderate Increase ◽  
Normal Cycle ◽  
Antral Follicles ◽  
Follicular Maturation ◽  
Follicular Activity

In order to elucidate the mechanism of the resumption of follicular activity and ovulation in rats, levels of FSH, LH and prolactin in plasma and pituitary gland and ovarian follicular development were quantified after removal of the litter on day 3 of lactation (day of parturition = day 0 of lactation). Such removal resulted in ovulation of 13 oocytes 4 days later, a number comparable with that found in normal cyclic rats. Plasma levels of prolactin were high during lactation but markedly decreased after removal of the litter. Although plasma concentrations of FSH and LH did not change during days 3–7 of lactation, there was an FSH surge between 24 and 30 h after removal of the litter. Plasma concentrations of LH also increased slightly but significantly by 24 h after removal of the litter and this value persisted during the following 2 days. Surges of FSH, LH and prolactin occurred at 17.00 h 3 days after pups were removed. Removal of the litter did not increase pituitary contents of FSH, LH and prolactin and a marked reduction in pituitary levels of FSH and LH, but not of prolactin, occurred at 17 00 h 3 days after removal of the litter. A quantitative study of follicular development indicated that follicles larger than 401 μm in diameter were absent during days 3–7 of lactation. However, the number and size of antral follicles increased by 30 h after removal of the litter, probably due to the increases in plasma levels of FSH and LH, and follicles larger than 601 μm in diameter appeared 3 days after the young were removed. Although ovulation could not be induced by human chorionic gonadotrophin from days 3 to 5 of lactation, its administration 30 h after removal of the litter produced ovulation in all rats by the following morning. These results indicated that a moderate increase in FSH, although below the amounts released at the preovulatory surge, together with basal levels of LH which were within the range observed on the day of dioestrus during the normal cycle were responsible for the initiation of follicular maturation after removal of the litter.

Changes in the plasma concentrations of inhibin throughout the normal sheep oestrous cycle and after the infusion of FSH

1989 ◽  
Vol 120 (2) ◽  
pp. 295-305 ◽  
Author(s):  
A. S. McNeilly ◽  
I. A. Swanston ◽  
W. Crow ◽  
C. G. Tsonis ◽  
D. T. Baird
Keyword(s):  
Follicular Fluid ◽  
Plasma Concentrations ◽  
Follicular Phase ◽  
Oestrous Cycle ◽  
Secretion Rate ◽  
Metabolic Clearance ◽  
Α Subunit ◽  
Sephadex Column ◽  
Luteal Regression ◽  
Ovarian Inhibin

ABSTRACT A radioimmunoassay for inhibin was developed using a peptide containing the 1–26 amino acid sequence of the N-terminus of the α-chain of 32 kDa porcine inhibin as immunogen, and 125I-labelled tracer. Evaluation of this assay using Sephadex column chromatography, chromatoelectrophoresis and immunoblotting confirmed that it measured all forms of inhibin present in sheep follicular fluid and was suitable for measurement of inhibin in sheep plasma. There was no evidence of the presence of free α-subunit in either sheep follicular fluid or ovarian vein plasma. The concentration of inhibin in jugular plasma throughout the follicular and luteal phases of four ewes with ovarian autotransplants was measured. The ovarian secretion of inhibin and oestradiol were also measured simultaneously throughout the follicular phase in a spontaneous cycle and after infusion of NIH-oFSH-S14 at 10 μg/h for 48 h following premature luteal regression induced by prostaglandin. The results showed: (1) no change in the peripheral concentration of inhibin throughout the cycle except an increase related to the periovulatory increase in FSH and LH. (2) Following luteal regression, the concentration of FSH fell as the secretion rate of oestradiol increased. During this time there was no significant change in the peripheral concentration of inhibin or ovarian inhibin secretion rate. (3) Following the infusion of FSH there was a marked increase in the concentration of inhibin in both ovarian and peripheral plasma and an increase in ovarian inhibin secretion rate. (4) The calculated metabolic clearance rate of inhibin, 20·3 ml/min, is similar to that of FSH. We conclude that in the ewe the ovarian inhibin secretion rate is stimulated by FSH and, although inhibin may modulate the basal secretion of FSH, a change in its secretion does not account for the fall in FSH which occurs during the follicular phase of the sheep oestrous cycle. Journal of Endocrinology (1989) 120, 295–305

Parallel Reduction of Plasma Levels of High and Low Molecular Weight Kininogen in Patients with Cirrhosis

1999 ◽  
Vol 82 (11) ◽  
pp. 1428-1432 ◽  
Author(s):  
Cheryl Scott ◽  
Francesco Salerno ◽  
Elettra Lorenzano ◽  
Werner Müller-Esterl ◽  
Angelo Agostoni ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Liver Disease ◽  
Liver Function ◽  
Plasma Levels ◽  
Plasma Concentrations ◽  
Normal Subjects ◽  
Low Molecular Weight ◽  
Major Band ◽  
Sds Page ◽  
Normal Controls

SummaryLittle is known about the regulation of high-molecular-weight-kininogen (HK) and low-molecular-weight-kininogen (LK) or the relationship of each to the degree of liver function impairment in patients with cirrhosis. In this study, we evaluated HK and LK quantitatively by a recently described particle concentration fluorescence immunoassay (PCFIA) and qualitatively by SDS PAGE and immunoblotting analyses in plasma from 33 patients with cirrhosis presenting various degrees of impairment of liver function. Thirty-three healthy subjects served as normal controls. Patients with cirrhosis had significantly lower plasma levels of HK (median 49 μg/ml [range 22-99 μg/ml]) and LK (58 μg/ml [15-100 μg/ml]) than normal subjects (HK 83 μg/ml [65-115 μg/ml]; LK 80 μg/ml [45-120 μg/ml]) (p < 0.0001). The plasma concentrations of HK and LK were directly related to plasma levels of cholinesterase (P < 0.0001) and albumin (P < 0.0001 and P < 0.001) and inversely to the Child-Pugh score (P < 0.0001) and to prothrombin time ratio (P < 0.0001) (reflecting the clinical and laboratory abnormalities in liver disease). Similar to normal individuals, in patients with cirrhosis, plasma HK and LK levels paralleled one another, suggesting that a coordinate regulation of those proteins persists in liver disease. SDS PAGE and immunoblotting analyses of kininogens in cirrhotic plasma showed a pattern similar to that observed in normal controls for LK (a single band at 66 kDa) with some lower molecular weight forms noted in cirrhotic plasma. A slight increase of cleavage of HK (a major band at 130 kDa and a faint but increased band at 107 kDa) was evident. The increased cleavage of HK was confirmed by the lower cleaved kininogen index (CKI), as compared to normal controls. These data suggest a defect in hepatic synthesis as well as increased destructive cleavage of both kininogens in plasma from patients with cirrhosis. The decrease of important regulatory proteins like kininogens may contribute to the imbalance in coagulation and fibrinolytic systems, which frequently occurs in cirrhotic patients.

Plasma Thrombospondin as an Indicator of Intravascular Platelet Activation in Patients with Vasculitis

1987 ◽  
Vol 58 (03) ◽  
pp. 850-852 ◽  
Author(s):  
M B McCrohan ◽  
S W Huang ◽  
J W Sleasman ◽  
P A Klein ◽  
K J Kao
Keyword(s):  
Platelet Activation ◽  
Plasma Levels ◽  
Half Life ◽  
Degradation Products ◽  
Plasma Concentrations ◽  
Primary Source ◽  
Positive Correlation ◽  
Activation Marker ◽  
Fibrin Degradation Products ◽  
The Mean

SummaryThe use of plasma thrombospondin (TSP) concentration was investigated as an indicator of intravascular platelet activation. Patients (n = 20) with diseases that have known vasculitis were included in the study. The range and the mean of plasma TSP concentrations of patients with vasculitis were 117 ng/ml to 6500 ng/ml and 791±1412 ng/ml (mean ± SD); the range and the mean of plasma TSP concentrations of control individuals (n = 33) were 13 ng/ml to 137 ng/ml and 59±29 ng/ml. When plasma TSP concentrations were correlated with plasma concentrations of another platelet activation marker, β-thromboglobulin (P-TG), it was found that the TSP concentration inei eased exponentially as the plasma β-TG level rose. A positive correlation between plasma levels of plasma TSP and serum fibrin degradation products was also observed. The results suggest that platelets are the primary source of plasma TSP in patients with various vasculitis and that plasma TSP can be a better indicator than β-TG to assess intravascular platelet activation due to its longer circulation half life.

Elevated Circulating P-Selectin in Insulin Dependent Diabetes Mellitus

1996 ◽  
Vol 76 (03) ◽  
pp. 328-332 ◽  
Author(s):  
Bernd Jilma ◽  
Peter Fasching ◽  
Christine Ruthner ◽  
Anna Rumplmayr ◽  
Sabine Ruzicka ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Plasma Levels ◽  
Plasma Concentrations ◽  
Insulin Dependent Diabetes Mellitus ◽  
Interquartile Range ◽  
Insulin Dependent Diabetes ◽  
Dependent Diabetes Mellitus ◽  
Intergroup Comparison ◽  
Median Plasma ◽  
Insulin Dependent

SummaryBased on findings that showed increased P-selectin expression on platelets and on choroidal microvessels of patients with insulin dependent diabetes mellitus (IDDM), we hypothesized that also plasma concentrations of circulating (c)P-selectin would be increased in these patients.The aim of this study was to compare the plasma levels of cP-selec-tin between non-smoking patients with IDDM, treated with an intensified insulin therapy, and healthy controls. The study design was prospective, cross-sectional and analyst-blinded. Subjects were matched individually for sex, age and body mass index. Plasma levels of cP-selectin and of von Willebrand antigen (vWF-Ag) were determined by enzyme linked immunoassays.Forty-two pairs were available for intergroup comparison. Median plasma concentrations of cP-selectin in patients with IDDM (285 ng/ml; interquartile range: 233-372) were on average 21% higher than those of controls (236 ng/ml; interquartile range: 175-296; p = 0.004). Also, median plasma levels of vWF-Ag were 10% higher in patients (96 U/dl; interquartile range: 82-127) than controls (87 U/dl; interquartile range: 70-104; p = 0.025). There was no correlation between plasma concentrations of cP-selectin and vWF-Ag levels in either group (p ώ0.05).In conclusion, our results of increased cP-selectin levels are in line with increased P-selectin expression on platelets and on choroidal microvessels found in patients with IDDM. In view of the currently developed small molecule inhibitors of cell adhesion molecules, these independent observations together may provide a sound rationale to select P-selectin as a target for treating or preventing IDDM-associated micro- or macrovascular complications.

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.

Studies of the oestrous cycle, oestrus and pregnancy in the koala (Phascolarctos cinereus)

Reproduction ◽  
2000 ◽  
pp. 49-57 ◽  
Author(s):  
SD Johnston ◽  
MR McGowan ◽  
P O'Callaghan ◽  
R Cox ◽  
V Nicolson
Keyword(s):  
Luteal Phase ◽  
Post Partum ◽  
Plasma Concentrations ◽  
External Genitalia ◽  
Oestrous Cycle ◽  
Phascolarctos Cinereus ◽  
Pregnant Females ◽  
Peripheral Plasma ◽  
The Mean ◽  
High Concentrations

As an integral part of the development of an artificial insemination programme in the captive koala, female reproductive physiology and behaviour were studied. The oestrous cycle in non-mated and mated koalas was characterized by means of behavioural oestrus, morphology of external genitalia and changes in the peripheral plasma concentrations of oestradiol and progestogen. The mean (+/- SEM) duration of the non-mated oestrous cycle and duration of oestrus in 12 koalas was 32.9 +/- 1.1 (n = 22) and 10.3 +/- 0.9 (n = 24) days, respectively. Although the commencement of oestrous behaviour was associated with increasing or high concentrations of oestradiol, there were no consistent changes in the morphology or appearance of the clitoris, pericloacal region, pouch or mammary teats that could be used to characterize the non-mated cycle. As progestogen concentrations remained at basal values throughout the interoestrous period, non-mated cycles were considered non-luteal and presumed anovulatory. After mating of the 12 koalas, six females gave birth with a mean (+/- SEM) gestation of 34.8 +/- 0.3 days, whereas the remaining six non-parturient females returned to oestrus 49.5 +/- 1. 0 days later. After mating, oestrous behaviour ceased and the progestogen profile showed a significant increase in both pregnant and non-parturient females, indicating that a luteal phase had been induced by the physical act of mating. Progestogen concentrations throughout the luteal phase of the pregnant females were significantly higher than those of non-parturient females. Parturition was associated with a decreasing concentration of progestogen, which was increased above that of basal concentrations until 7 days post partum.

scholarly journals Ileal transposition helps to regulate plasma hepatokine levels in obese Zucker (Crl:ZUC(ORL)-Leprfa) rats

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Dominika Stygar ◽  
Tomasz Sawczyn ◽  
Agnieszka Dulska ◽  
Elżbieta Chełmecka ◽  
Łukasz Mielańczyk ◽  
...  
Keyword(s):  
Body Weight ◽  
Plasma Levels ◽  
Plasma Concentrations ◽  
The Body ◽  
Retinol Binding Protein ◽  
Fibroblast Growth Factor 21 ◽  
Adult Males ◽  
Total Lipids ◽  
Ileal Transposition ◽  
Sham Surgery

AbstractWe studied the long-term effect of ileal transposition (IT) metabolic surgery on the hepatokines: retinol-binding protein-4 (RBP4), α-2-HS-glycoprotein (aHSG/fetuin-A), and fibroblast growth factor 21 (FGF21), C-reactive protein (CRP) plasma levels, glucose metabolism, body weight, liver histology, as well as total lipids concentration in muscle, liver, and fat tissue of obese Zucker (Crl:ZUC(ORL)-Leprfa) rats. 14 adult males were randomly submitted either to IT or SHAM (control) surgery. Pre-operative hepatokines plasma levels were not significantly different in rats submitted to IT or SHAM protocol. Three months after the procedures the plasma levels of RBP4, aHSG, FGF21, and CRP were significantly lower in IT-operated animals when compared to SHAM-operated group. Three and 12 weeks after the IT and SHAM surgery, the AUCOGTT were significantly lower than AUCOGTT before the surgery. HOMA-IR was lower in rats after IT surgery in comparison to the SHAM-operated rats. Muscle and liver total lipids concentration was reduced after the IT procedure when compared to pre-IT conditions. IT had a significant reductive impact on the body weight in comparison to SHAM surgery in the 4th, 6th, 8th, and 10th week after the surgery. We conclude that IT reduces hepatokines’ plasma concentrations, muscle and liver total lipids concentration but not the inflammatory processes in the liver of Zucker (Crl:ZUC(ORL)-Leprfa) rats.

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