RADIOIMMUNOASSAY OF LUTEINIZING HORMONE-RELEASING HORMONE (LH-RH) IN SERUM FROM MAN, SHEEP AND RAT

1974 ◽  
Vol 75 (4) ◽  
pp. 625-635 ◽  
Author(s):  
S. L. Jeffcoate ◽  
H. M. Fraser ◽  
D. T. Holland ◽  
A. Gunn
Keyword(s):  
Luteinizing Hormone ◽  
Intravenous Injection ◽  
Jugular Vein ◽  
Extraction Procedure ◽  
Rabbit Antiserum ◽  
Luteinizing Hormone Releasing Hormone ◽  
Releasing Hormone ◽  
Methanol Extraction ◽  
Serum Assay ◽  
Lh Rh

ABSTRACT A radioimmunoassay for luteinizing hormone-releasing hormone (LH-RH) has been developed. Antisera were raised against the decapeptide conjugated to albumin in rabbits and against the 3-10 octapeptide conjugated to albumin in rats. LH-RH was iodinated with 125I and purified on Sephadex, the most immunoreactive fractions of the 125I-LH-RH being eluted after 125I. A serum assay was developed using a simple methanol extraction procedure. The rabbit antiserum could detect levels of LH-RH in the jugular vein of the sheep at various times and in the rat on the afternoon of pro-oestrus. The assay using the rat antiserum was 30 times more sensitive and could detect LH-RH in peripheral serum in man. 10-20 pg/ml in peripheral serum of man, but the RIA could be used to measure the disappearance and clearance of LH-RH after intravenous injection of large test doses (Jeffcoate et al. 1974a). In this study we describe the details of a RIA of LH-RH in serum from man, sheep and rat.

Acidic Aqueous Extraction of Hypothalamic Luteinizing Hormone Releasing Hormone to Study Biological Effects

1974 ◽  
Vol 52 (3) ◽  
pp. 754-758 ◽  
Author(s):  
S. H. Shin ◽  
C. J. Howitt
Keyword(s):  
Luteinizing Hormone ◽  
Biological Effects ◽  
Extraction Procedure ◽  
Extraction Methods ◽  
Water Soluble ◽  
Acid Extraction ◽  
Luteinizing Hormone Releasing Hormone ◽  
Releasing Hormone ◽  
Aqueous Solvent ◽  
Lh Rh

Several aqueous solvent systems were tested for their efficiency in extracting luteinizing hormone releasing hormone (LH-RH) from rat hypothalamus. Although LH-RH is a water-soluble decapeptide, neutral distilled water extracted only 10% of the LH-RH obtained using acid extraction methods. The efficiency of the acid extraction procedure suggests that in the hypothalamus the releasing hormone is bound to a relatively large molecular weight compound. Using the acidic extraction procedure, we found that hypothalamic LH-RH content is significantly lower in the castrated animal than in the normal rat.

EFFECTS OF LUTEINIZING HORMONE RELEASING HORMONE ON PLASMA FOLLICLE-STIMULATING HORMONE AND LUTEINIZING HORMONE LEVELS IN THE FERRET

1977 ◽  
Vol 73 (1) ◽  
pp. 37-52 ◽  
Author(s):  
B. T. DONOVAN ◽  
M. B. TER HAAR
Keyword(s):  
Luteinizing Hormone ◽  
Intravenous Injection ◽  
Follicle Stimulating Hormone ◽  
Luteinizing Hormone Releasing Hormone ◽  
Releasing Hormone ◽  
Hormone Levels ◽  
Oestradiol Treatment ◽  
Gonadotrophin Secretion ◽  
Lh Rh ◽  
Lh Secretion

SUMMARY Heterologous radioimmunoassays for FSH and LH were employed to examine the effect of synthetic LH-RH upon gonadotrophin secretion in the ferret. Intravenous injection of 4 μg LH-RH induced a surge of FSH and of LH secretion in male and in female animals. In intact and in castrated males, the rise of LH was much more marked than that of FSH. The gonadotrophin response to LH-RH was greater in anoestrous than in oestrous females; FSH secretion was not enhanced during oestrus. Ovariectomized females behaved as anoestrous females with respect to LH secretion, while FSH secretion remained unchanged. Treatment of ovariectomized females with progesterone did not alter the pattern of response to LH-RH, but oestradiol treatment depressed the reaction to match that seen in oestrous females. Repetitive injections of LH-RH induced repetitive surges of FSH and LH in anoestrous females, but only of LH during oestrus: slow i.v. infusion of LH-RH induced a sustained elevation of plasma LH levels both in oestrous and in anoestrous females; again FSH levels rose only in anoestrous females. Injection of synthetic TRH did not alter gonadotrophin secretion in corresponding groups of male or female ferrets.

DIFFERENTIAL CONTROL OF LUTEINIZING HORMONE AND FOLLICLE-STIMULATING HORMONE BY LUTEINIZING HORMONE RELEASING HORMONE IN THE RAM

1979 ◽  
Vol 80 (1) ◽  
pp. 133-140 ◽  
Author(s):  
G. A. LINCOLN
Keyword(s):  
Luteinizing Hormone ◽  
Jugular Vein ◽  
Repeated Treatment ◽  
Luteinizing Hormone Releasing Hormone ◽  
Releasing Hormone ◽  
Low Concentrations ◽  
Small Doses ◽  
High Level ◽  
Lh Rh ◽  
Differential Control

Adult Soay rams with low concentrations of gonadotrophins in the circulation as a result of 12 weeks of exposure to long daylengths (16 h light: 8 h darkness) were given small doses (100 ng) of synthetic luteinizing hormone releasing hormone (LH-RH) into the jugular vein two, four or seven times/day for 10 days. Each injection of LH-RH induced a transitory increase in the concentration of LH and testosterone in the plasma, whereas the concentration of FSH showed little immediate change, After repeated treatment with pulses of LH-RH, the responses of LH and testosterone became slightly enhanced and the plasma concentration of FSH became permanently raised; these changes were most conspicuous in the animals receiving the most frequent injections. At the end of the study when the injections of LH-RH were stopped, the concentrations of LH and testosterone remained low but the concentrations of FSH continued to be maintained at a high level for at least 24 h.

Plasma cortisol response to thyrotrophin releasing hormone and luteinizing hormone releasing hormone in healthy kennel dogs and in dogs with pituitary-dependent hyperadrenocorticism

1982 ◽  
Vol 93 (3) ◽  
pp. 365-369 ◽  
Author(s):  
R. Stolp ◽  
R. J. M. Croughs ◽  
J. C. Meijer ◽  
A. Rijnberk
Keyword(s):  
Plasma Concentration ◽  
Luteinizing Hormone ◽  
Intravenous Injection ◽  
Plasma Cortisol ◽  
Cortisol Response ◽  
Thyrotrophin Releasing Hormone ◽  
Luteinizing Hormone Releasing Hormone ◽  
Releasing Hormone ◽  
Lh Rh ◽  
Lh Releasing Hormone

The change in the plasma concentration of cortisol after the administration of thyrotrophin releasing hormone (TRH) and LH releasing hormone (LH-RH) was studied in normal dogs and in dogs with pituitary-dependent hyperadrenocorticism (PDH). The normal dogs showed a small but significant increase in the plasma concentration of cortisol 15 min after intravenous injection of TRH and LH-RH. In ten of the dogs with PDH the response to TRH was not significantly different from that in the normal dogs, but in 13 the response was significantly greater. In 15 of the dogs with PDH the response to LH-RH administration was within or below the range of responses in the normal dogs and in only one dog was the response to LH-RH greater than that in the normal dogs. These findings are discussed in relation to the pathogenesis of PDH.

EFFECT OF CORTISOL OR ADRENOCORTICOTROPHIN ON RELEASE OF LUTEINIZING HORMONE INDUCED BY LUTEINIZING HORMONE RELEASING HORMONE IN THE DAIRY HEIFER

1982 ◽  
Vol 92 (1) ◽  
pp. 141-146 ◽  
Author(s):  
R. L. MATTERI ◽  
G. P. MOBERG
Keyword(s):  
Luteinizing Hormone ◽  
Luteinizing Hormone Releasing Hormone ◽  
Releasing Hormone ◽  
Dairy Heifers ◽  
Significant Difference ◽  
Significant Depression ◽  
Lh Rh ◽  
Lh Releasing Hormone ◽  
And Control ◽  
Slight Depression

During treatment with cortisol or ACTH, dairy heifers were given two doses of LH releasing hormone (LH-RH) spaced 1·5 h apart. Serum concentrations of cortisol and LH were monitored during each treatment. Treatment with both ACTH and cortisol raised plasma cortisol levels above the respective saline controls (P<0·001). Neither treatment affected basal LH concentrations. A slight depression in LH response was seen in the cortisol-treated animals after the first LH-RH injection, as shown by a statistically significant depression at three of the sample times. There was no significant difference between treated and control LH values after the second LH-RH administration. Treatment with ACTH resulted in significantly reduced LH values at all sample times after both injections of LH-RH.

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.

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