Induction of Luteinizing Hormone (LH) Release and Ovulation in Rats, Hamsters, and Rabbits by Synthetic Luteinizing Hormone—Releasing Factor (LRF)

Humphrey, Ronald R.; Dermody, W. C.; Brink, H. O.; Bousley, Ferris G.; Schottin, N. H.; Sakowski, R.; Vaitkus, J W; Veloso, H. T.; Reel, Jerry R.

doi:10.1210/endo-92-5-1515

Cited by 51 publications

(18 citation statements)

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“…These results thus confirm that GtH release can be induced in oestradiol-primed coho salmon parr. Moreover, the observed increases in plasma GtH following LHRHa intubation are in accord with other reports of GtH release following LHRHa administration per os to steroid-blocked rats (Amoss et al, 1972;Humphrey et al, 1973). However, GtH elevations in mammals were transient (less than 120 min) unlike those in the present study in which elevated levels were observed at the termination of the experiment at 24h.…”

Section: Discussionsupporting

confidence: 93%

Gonadotropin release following oral delivery of luteinizing hormone‐releasing hormone and its superactive analogue (des‐Gly¹⁰ [D‐Ala⁶] LHRH ethylamide) to 17β‐oestradiol‐primed coho salmon, Oncorhynchus kisutch (Walbaum)

McLean

Parker

Warby

et al. 1991

Journal of Fish Biology

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The permeability of the coho salmon, Oncorhynchus kisutch (Walbaum), gut to orally administered LHRH and LHRHa (des-Gly'" [D-Ala6] LHRH ethylamide) was examined over a 360 min time-course. Both forms of LHRH were detected in the blood plasma oftreated fish within 30min of delivery. Retained biological activity of the absorbed LHRH was also assessed. Oral delivery of LHRH or LHRHa to 1761-oestradiol-primed coho resulted in a significant (PiO.Ol) release of gonadotropin (GtH) when compared to saline intubated, 17/l-oestradiol-primed animals. The dose response of I7/7-oestradiol-primed coho salmon to orally delivered LHRHa revealed that maximal G t H release occurred at doses between 2.0 and 20 pg LHRHa per g body weight.

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Section: Discussionsupporting

confidence: 93%

Gonadotropin release following oral delivery of luteinizing hormone‐releasing hormone and its superactive analogue (des‐Gly¹⁰ [D‐Ala⁶] LHRH ethylamide) to 17β‐oestradiol‐primed coho salmon, Oncorhynchus kisutch (Walbaum)

McLean

Parker

Warby

et al. 1991

Journal of Fish Biology

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“…Good examples are provided by luteinizing hormone releasing factor (L.H.R.F.) (Amoss et al, 1972;Humphrey et al, 1973;Nishi et al, 1975) and thyrotropin releasing factor (Bowers et al, 1970;Hellier, 1972;Ormiston, 1972) both of which are active when administered orally. The former is a decapeptide with blocked termini, i.e.…”

Section: Evidence For Absorption Of Intact Peptidesmentioning

confidence: 99%

Entry of Peptides of Dietary Origin into the Circulation

Gardner

1983

Nutr Health

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Current theories of protein digestion and absorption state that free amino acids are the only significant form in which amino-N crosses the intestine and enters the systemic circulation. Nevertheless, there is now abundant evidence that intact peptides escaping digestion (or undergoing only partial digestion) and even whole protein molecules can enter the circulation in health and disease. Since peptides are now believed to play a major role in neural and endocrine regulation and in view of the fact that intestinal digestive activity can be reduced and intestinal 'permeability' increased in a variety of pathological conditions, the possibility that absorbed intact peptides can exert biological activities in peripheral tissues and can elicit symptoms in susceptible individuals now requires critical evaluation. These considerations may provide a physiological rationale for changing the source(s) of dietary protein in cases where food allergies/dietary sensitivities are suspected.

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“…Ovarian follicles capable of ovulating may not be present at certain times of the year, and LH or its releasing hormone (gonadorelin) will not induce ovulation. The variability observed by Humphrey et al (15) may be due to seasonality and/or may be due to variability of the bioassay. • LH Release.…”

Section: Discussionmentioning

confidence: 98%

“…• Hamster Ovulation. This bioassay involves the administration of phenobarbital to golden hamsters exhibiting estrous cycles (15). The ovulation block induced by phenobarbital may be overcome by gonadorelin treatment.…”

Section: Discussionmentioning

confidence: 99%

Gonadorelin-Induced Testosterone Release: A Biological Assay for Quality Assurance of Gonadorelin in Veterinary Medicine

Kesler

Summers

Peterson

et al. 1999

Drug Development and Industrial Pharmacy

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Two experiments were conducted with bulls administered norgestomet and gonadorelin to determine if the gonadorelin-induced release of testosterone could be developed into a biological assay for quality assurance of gonadorelin. Implants containing norgestomet (0 to 36 mg) reduced the episodic release (r = -.81; P < .05) and mean concentrations of testosterone (r = -.82; P < .05). Gonadoreline-induced testosterone release increased (r = .99; P < .05) with increasing dosage of gonadorelin (up to 5 micrograms) in norgestomet-implanted bulls (36 mg). Maximal testosterone was released (> sixfold increase) with 5 to 40 micrograms of gonadorelin. In summary, the gonadorelin-induced testosterone release in bulls administered a synthetic progestin is a sensitive (0.008 microgram per kg body weight for 5 micrograms of gonadorelin) biological assay with a rapid turnaround time for the confirmation of gonadorelin potency. Based on a per-kg-body-weight basis, the norgestomet-treated bull is the most sensitive biological assay model.

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Induction of Luteinizing Hormone (LH) Release and Ovulation in Rats, Hamsters, and Rabbits by Synthetic Luteinizing Hormone—Releasing Factor (LRF)

Cited by 51 publications

References 0 publications

Gonadotropin release following oral delivery of luteinizing hormone‐releasing hormone and its superactive analogue (des‐Gly¹⁰ [D‐Ala⁶] LHRH ethylamide) to 17β‐oestradiol‐primed coho salmon, Oncorhynchus kisutch (Walbaum)

Gonadotropin release following oral delivery of luteinizing hormone‐releasing hormone and its superactive analogue (des‐Gly¹⁰ [D‐Ala⁶] LHRH ethylamide) to 17β‐oestradiol‐primed coho salmon, Oncorhynchus kisutch (Walbaum)

Entry of Peptides of Dietary Origin into the Circulation

Gonadorelin-Induced Testosterone Release: A Biological Assay for Quality Assurance of Gonadorelin in Veterinary Medicine

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Induction of Luteinizing Hormone (LH) Release and Ovulation in Rats, Hamsters, and Rabbits by Synthetic Luteinizing Hormone—Releasing Factor (LRF)

Cited by 51 publications

References 0 publications

Gonadotropin release following oral delivery of luteinizing hormone‐releasing hormone and its superactive analogue (des‐Gly10 [D‐Ala6] LHRH ethylamide) to 17β‐oestradiol‐primed coho salmon, Oncorhynchus kisutch (Walbaum)

Gonadotropin release following oral delivery of luteinizing hormone‐releasing hormone and its superactive analogue (des‐Gly10 [D‐Ala6] LHRH ethylamide) to 17β‐oestradiol‐primed coho salmon, Oncorhynchus kisutch (Walbaum)

Entry of Peptides of Dietary Origin into the Circulation

Gonadorelin-Induced Testosterone Release: A Biological Assay for Quality Assurance of Gonadorelin in Veterinary Medicine

Contact Info

Product

Resources

About

Gonadotropin release following oral delivery of luteinizing hormone‐releasing hormone and its superactive analogue (des‐Gly¹⁰ [D‐Ala⁶] LHRH ethylamide) to 17β‐oestradiol‐primed coho salmon, Oncorhynchus kisutch (Walbaum)

Gonadotropin release following oral delivery of luteinizing hormone‐releasing hormone and its superactive analogue (des‐Gly¹⁰ [D‐Ala⁶] LHRH ethylamide) to 17β‐oestradiol‐primed coho salmon, Oncorhynchus kisutch (Walbaum)