Separation of Follicle-Stimulating Hormone-Releasing Factor from Luteinizing Hormone-Releasing Factor

Dhariwal, A. P. S.; Nallar, R; Batt, Margaret; McCann, Samuel M.

doi:10.1210/endo-76-2-290

Cited by 68 publications

(18 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Experimental evidence to support this theory has included the identification of separate fractions of FSH-RH and LH-releasing hormone activity in sheep hypothalamic extracts (Dhariwal et al 1965), as well as selectively impaired release of FSH after lesioning of the dorsal anterior hypothalamic area (Lumpkin & McCann 1984) and posterior/-mid infundibulum (Marubayashi et al 1999). Moreover, GnRH-independent pulses of FSH have been detected by determining concentrations of FSH in the hypothalamichypophyseal portal circulation (Padmanabhan et al 2003).…”

Section: Introductionmentioning

confidence: 99%

Evidence that lamprey GnRH-III does not release FSH selectively in cattle

Amstalden¹,

Zieba²,

Garcia³

et al. 2004

Reproduction

View full text Add to dashboard Cite

Experiments were performed to test the hypothesis that lamprey GnRH-III (lGnRH-III) selectively releases FSH. Primary cultures of bovine adenohypophyseal cells were treated with mammalian GnRH (mGnRH) and lGnRH-III (10 29 , 10 28, 10 27and 10 26 M) or control media in Experiment 1. All doses of mGnRH and the two highest doses of lGnRH-III stimulated (P < 0.001) a non-selective release of LH and FSH. In Experiments 2 -4, Latin Square designs were utilized in vivo to examine whether physiological and hormonal milieu regulate putative selective effects of lGnRH-III. In Experiments 2 and 3, ovariectomized cows with basal levels of estradiol only (Experiment 2) or in combination with luteal phase levels of progesterone (Experiment 3) were injected with mGnRH and lGnRH-III (0.055, 0.11, 0.165 and 1.1 mg/kg body weight (BW) and saline. All doses of mGnRH released (P < 0.001) LH and FSH, but only the highest dose of lGnRH-III stimulated (P < 0.001) a non-selective release of both LH and FSH (Experiment 3). For Experiments 4A and 4B, intact, mid-luteal phase cows were injected with mGnRH and lGnRH-III (1.1 mg/kg BW; Experiment 4A), lGnRH-III (1.1 and 4.4 mg/kg BW; Experiment 4B) and saline. As before, mGnRH released (P < 0.001) both LH and FSH at all doses. In contrast, lGnRH-III at the highest dose released (P < 0.001) LH but not FSH. These findings suggest that lGnRH-III may act as a weak competitor for the mGnRH receptor and do not support the hypothesis that it selectively releases FSH in cattle.

show abstract

Section: Introductionmentioning

confidence: 99%

Evidence that lamprey GnRH-III does not release FSH selectively in cattle

Amstalden¹,

Zieba²,

Garcia³

et al. 2004

Reproduction

View full text Add to dashboard Cite

show abstract

“…Although the evidence from physiological studies for a separate hypothalamic control of follicle-stimulating hormone (FSH) release distinct from that of luteinizing hormone (LH) is compelling (1)(2)(3)(4)(5), proof of the separate hypothalamic control of FSH rests on the identification of an FSH-releasing factor (FSHRF). Crude extracts of the organum vasculosum lamina terminalis contained much more FSH-releasing activity than accounted for by the content of LH-releasing hormone (LHRH), and the slope of the dose-response curve in the in vitro bioassay for FSH release was much steeper than that obtained with LHRH (6).…”

mentioning

confidence: 99%

“…FSHRF was purified originally from sheep hypothalami by gel filtration on Sephadex G-25 followed by carboxymethyl cellulose chromatography (2,3). The release of FSH was measured by bioassay using either in vivo or in vitro assays of FSH-releasing activity (2,3).…”

mentioning

confidence: 99%

“…The release of FSH was measured by bioassay using either in vivo or in vitro assays of FSH-releasing activity (2,3). Because LHRH has intrinsic FSH-releasing activity (8) and because Schally et al could not separate FSH-from LH-releasing activity by fractionation on Sephadex G-25 using in vitro assays and measurement of FSH by immunoassay, they concluded that there was only one gonadotropin-releasing hormone (9).…”

mentioning

confidence: 99%

“…Lumpkin et al (10) separated the FSH-from the LHreleasing activity on the same column of Sephadex G-25 used originally (2) with bioassay of the activity in vivo in the ovariectomized (OVX), estrogen-progesterone-blocked rat, the original assay used to detect and separate the FSHRF from LHRH (2). The only difference was that plasma FSH and LH were measured by immunoassay rather than by bioassay.…”

mentioning

confidence: 99%

See 2 more Smart Citations

A hypothalamic follicle-stimulating hormone-releasing decapeptide in the rat

Karanth

Walczewska

et al. 1997

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

Previous studies indicated that there is a separate hypothalamic control of follicle-stimulating hormone (FSH) release distinct from that of luteinizing hormone (LH). An FSH-releasing factor (FSHRF) was purified from rat and sheep hypothalami, but has not been isolated. We hypothesized that FSHRF might be an analogue of mammalian luteinizing hormone-releasing hormone (m-LHRH) and evaluated the activity of many analogues of m-LHRH and of the known LHRHs found in lower forms. Here we demonstrate that lamprey (l) LHRH-III has a potent, dose-related FSH-but not LH-releasing action on incubated hemipituitaries of male rats. l-LHRH-I on the other hand, had little activity to release either FSH or LH. m-LHRH was equipotent to l-LHRH-III to release FSH, but also had a high potency to release LH in contrast to l-LHRH-III that selectively released FSH. Chicken LHRH-II had considerable potency to release both LH and FSH, but no selectivity in its action. Salmon LHRH had much less potency than the others tested, except for l-LHRH-I, and no selectivity in its action. Because ovariectomized, estrogen, progesterone-treated rats are a sensitive in vivo assay for FSHand LH-releasing activity, we evaluated l-LHRH-III in this assay and found that it had a completely selective stimulatory effect on FSH release at the two doses tested (10 and 100 pmols). Therefore, l-LHRH-III is a highly potent and specific FSH-releasing peptide that may enhance fertility in animals and humans. It may be the long sought after m-FSHRF.Although the evidence from physiological studies for a separate hypothalamic control of follicle-stimulating hormone (FSH) release distinct from that of luteinizing hormone (LH) is compelling (1-5), proof of the separate hypothalamic control of FSH rests on the identification of an FSH-releasing factor (FSHRF). Crude extracts of the organum vasculosum lamina terminalis contained much more FSH-releasing activity than accounted for by the content of LH-releasing hormone (LHRH), and the slope of the dose-response curve in the in vitro bioassay for FSH release was much steeper than that obtained with LHRH (6). Extracts of the posterior median eminence similarly contained more FSH-releasing activity than could be accounted for by the content of LHRH (7).FSHRF was purified originally from sheep hypothalami by gel filtration on Sephadex G-25 followed by carboxymethyl cellulose chromatography (2, 3). The release of FSH was measured by bioassay using either in vivo or in vitro assays of FSH-releasing activity (2, 3). Because LHRH has intrinsic FSH-releasing activity (8) and because Schally et al. could not separate FSH-from LH-releasing activity by fractionation on Sephadex G-25 using in vitro assays and measurement of FSH by immunoassay, they concluded that there was only one gonadotropin-releasing hormone (9).Lumpkin et al. (10) separated the FSH-from the LHreleasing activity on the same column of Sephadex G-25 used originally (2) with bioassay of the activity in vivo in the ovariectomized (OVX), estrogen-progesterone-...

show abstract

Neuroendocrine Control of Estrus and Ovulation

Amstalden

Williams

2014

Bovine Reproduction

View full text Add to dashboard Cite

Separation of Follicle-Stimulating Hormone-Releasing Factor from Luteinizing Hormone-Releasing Factor

Cited by 68 publications

References 0 publications

Evidence that lamprey GnRH-III does not release FSH selectively in cattle

Evidence that lamprey GnRH-III does not release FSH selectively in cattle

A hypothalamic follicle-stimulating hormone-releasing decapeptide in the rat

Neuroendocrine Control of Estrus and Ovulation

Contact Info

Product

Resources

About