FURTHER STUDIES ON THE NATURE OF THE IMMUNOREACTIVE LUTEINIZING HORMONE-RELEASING HORMONE (LH-RH)-LIKE PEPTIDE IN HUMAN URINE

1975 ◽  
Vol 78 (1) ◽  
pp. 232-238 ◽  
Author(s):  
S. L. Jeffcoate ◽  
Diane T. Holland
Keyword(s):  
Luteinizing Hormone ◽  
Ion Exchange ◽  
Human Urine ◽  
Chemical Nature ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Urine Samples ◽  
Luteinizing Hormone Releasing Hormone ◽  
Releasing Hormone ◽  
Lh Rh

ABSTRACT The chemical nature of the immunoreactive LH-RH-like peptide found in human urine has been investigated using ion-exchange chromatography on carboxymethyl (CM)-cellulose and a radioimmunoassay for LH-RH. A single immunoreactive substance was found in urine after LH-RH administration and in urine samples from untreated subjects. This substance did not have the mobility of either the synthetic decapeptide nor the 3–10 octapeptide on CM-cellulose and the evidence suggests that it may be the 2–10 nonapeptide of LH-RH.

CHROMATOGRAPHIC HETEROGENEITY OF IMMUNOREACTIVE LUTEINIZING HORMONE RELEASING HORMONE IN BLOOD FROM THE RABBIT, SHEEP AND RAT

1974 ◽  
Vol 62 (2) ◽  
pp. 333-340 ◽  
Author(s):  
S. L. JEFFCOATE ◽  
D. T. HOLLAND
Keyword(s):  
Luteinizing Hormone ◽  
Ion Exchange ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Serum Samples ◽  
Blood Samples ◽  
Luteinizing Hormone Releasing Hormone ◽  
Releasing Hormone ◽  
Lh Rh

SUMMARY Serum samples from rabbits, sheep and rats containing immunoreactive luteinizing hormone releasing hormone (LH-RH) have been extracted and fractionated by ion exchange chromatography on carboxymethylcellulose followed by radioimmunoassay of the fractions. Control experiments showed that the extraction and chromatographic procedures did not alter the mobility of synthetic LH-RH. Four immunoreactive components of circulating LH-RH in blood samples from various species at various times were identified on CM-cellulose columns. One of these had a mobility identical with that of synthetic LH-RH; of the others, two were eluted before and one after synthetic LH-RH. The nature, site of formation and possible significance of the extra components are discussed.

IMMUNOCHEMICAL AND CHROMATOGRAPHIC SIMILARITY OF RAT, RABBIT, CHICKEN AND SYNTHETIC LUTEINIZING HORMONE RELEASING HORMONES

1974 ◽  
Vol 62 (1) ◽  
pp. 85-91 ◽  
Author(s):  
S. L. JEFFCOATE ◽  
P. J. SHARP ◽  
H. M. FRASER ◽  
D. T. HOLLAND ◽  
A. GUNN
Keyword(s):  
Luteinizing Hormone ◽  
Ion Exchange ◽  
Thin Layer ◽  
Gel Filtration ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Active Fraction ◽  
Luteinizing Hormone Releasing Hormone ◽  
Lh Rh ◽  
Layer Chromatography

SUMMARY Luteinizing hormone releasing hormone (LH-RH) was detected in hypothalamic extracts of rats, rabbits and chickens using a radioimmunoassay for synthetic LH-RH decapeptide. The mobilities of the immunologically active fraction and of synthetic LH-RH were the same in various chromatographic systems (gel filtration on Sephadex, thin-layer chromatography on silica gel and ion-exchange chromatography on carboxymethylcellulose) suggesting that mammalian, avian and synthetic LH-RH's are closely related.

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.

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.

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.

Determination and Speciation of Arsenic in Human Urine by Ion-Exchange Chromatography/Flow Injection Analysis with Hydride Generation/Atomic Absorption Spectroscopy

1994 ◽  
Vol 77 (2) ◽  
pp. 441-445 ◽  
Author(s):  
O Jimenez de Blas ◽  
S Vicente Gonzalez ◽  
R Seisdedos Rodriguez ◽  
J Hernandez Mendez
Keyword(s):  
Ion Exchange ◽  
Atomic Absorption ◽  
Flow Injection ◽  
Hydride Generation ◽  
Inorganic Arsenic ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Urine Samples ◽  
Dimethylarsinic Acid ◽  
Total Arsenic

Abstract A flow injection–hydride generation/atomic absorption spectroscopic method for the measurement of total urinary arsenic and for the selective determination of inorganic arsenic, monomethylarsonic acid (MMAA), and dimethylarsinic acid (DMAA) was developed. Destruction of the organic matrix is necessary to measure total arsenic content of urine samples. Digestion of this matrix with HNO3–H2SO4–H2O2 is described. The separation of inorganic, monomethylated, and dimethylated arsenic compounds in urine was performed with ion-exchange chromatography on AG 50 W-X8 resin. Detection limits of 2 ppb for each arsenic form and of 3 ppb for total arsenic in urine analyzed after mineralization were found. Recoveries in triplicate urine samples spiked with 10 ppb inorganic arsenic, 20 ppb MMAA, and 40 ppb DMAA were 93, 91, and 85%, respectively. The precision (relative standard deviation) of the method obtained in 10 replicate analyses of urine samples spiked with arsenic metabolites varied from 3.2 to 4.6%. This method is applicable to urine samples in studies relating to arsenic exposure and its monitoring.

Sign in / Sign up

Export Citation Format

Share Document