Plasma Testosterone Concentration Predicts the Ovulatory Response of Coho Salmon (Oncorhynchus kisutch) to Gonadotropin-Releasing Hormone Analog

1987 ◽  
Vol 44 (7) ◽  
pp. 1351-1357 ◽  
Author(s):  
Martin S. Fitzpatrick ◽  
J. Michael Redding ◽  
Frank D. Ratti ◽  
Carl B. Schreck
Keyword(s):  
Coho Salmon ◽  
Plasma Concentrations ◽  
Oncorhynchus Kisutch ◽  
Gonadotropin Releasing Hormone ◽  
Plasma Testosterone ◽  
Releasing Hormone ◽  
Hormone Analog ◽  
Before And After ◽  
The Mean ◽  
Estradiol 17Β

Plasma concentrations of testosterone, 17α-hydroxy-20β-dihydroprogesterone (DHP), and estradiol-17β were determined in hatchery populations of adult female coho salmon (Oncorhynchus kisutch) before and after the fish were injected with gonadotropin-releasing hormone analog (GnRHa) to accelerate ovulation. Treatment with GnRHa significantly accelerated maturation over that observed in saline-injected controls; however, a number of females that received GnRHa did not ovulate for as long as 8 wk after treatment. Before treatment, the mean plasma levels of DHP did not differ between early- and late-ovulating females; estradiol differed sometimes, but not always; and testosterone was always higher in the early-ovulating fish. Thus, plasma concentrations of testosterone appear to be useful for predicting the sensitivity of coho salmon to GnRHa treatment for induced ovulation.

Effects of Mammalian and Salmon Gonadotropin-Releaslng Hormones and Analogues on Plasma Gonadotropin Levels and Ovulation in Coho Salmon (Oncorhynchus kisutch)

1987 ◽  
Vol 44 (11) ◽  
pp. 1930-1935 ◽  
Author(s):  
G. Van Der Kraak ◽  
E. M. Donaldson ◽  
H. M. Dye ◽  
G. A. Hunter ◽  
J. E. Rivier ◽  
...  
Keyword(s):  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Gonadotropin Releasing Hormone ◽  
High Rate ◽  
Agonist Activity ◽  
Releasing Hormone ◽  
Gonadotropin Release ◽  
Native Peptides ◽  
Derivatives Of

The effects of intraperitoneal injections of mammalian gonadotropin-releasing hormone (mGnRH) and salmon gonadotropin-releasing hormone (sGnRH; [Trp7, Leu8]-mGnRH) as well as analogues of each peptide on plasma gonadotropin levels and ovulation in coho salmon (Oncorhynchus kisutch) were investigated. The native peptides had similar potencies in terms of the magnitude and duration of the gonadotropin release response. Analogues including the D-Ala6 and (imbz1) D-His6 derivatives of [Pro9-NEt]-mGnRH and the D-Arg6 and D-Ala6 derivatives of [Pro9-NEt]-sGnRH stimulate a more prolonged increase in plasma gonadotropin levels than native forms of these peptides. Each of the analogue peptides at a dosage of 0.2 mg/kg body wt induced a high rate of ovulation; the native salmon peptide at the same dosage was also effective although the time of ovulation was delayed compared with the response to analogue peptides. A higher dosage of the native salmon peptide (1.0 mg/kg body wt) was less effective in stimulating gonadotropin release and failed to induce a high rate of ovulation. Our studies demonstrate that several analogues of mGnRH and sGnRH have superactive agonist activity in coho salmon and are effective in inducing ovulation in this species.

Short-term effects of gonadotropin-releasing hormone analogue treatment on leptin, ghrelin and peptide YY in girls with central precocious puberty

2021 ◽  
Vol 34 (4) ◽  
pp. 479-484
Author(s):  
Piyathida Wijarn ◽  
Preamrudee Poomthavorn ◽  
Patcharin Khlairit ◽  
Sarunyu Pongratanakul ◽  
Laor Chailurkit ◽  
...  
Keyword(s):  
Precocious Puberty ◽  
Peptide Yy ◽  
Central Precocious Puberty ◽  
Gonadotropin Releasing Hormone ◽  
Hormone Analogue ◽  
Short Term ◽  
Serum Leptin ◽  
Releasing Hormone ◽  
Gonadotropin Releasing Hormone Analogue ◽  
Before And After

Abstract Objectives To determine appetite-regulating hormone levels in girls with central precocious puberty (CPP) before and after 20 weeks of gonadotropin-releasing hormone analogue (GnRH-A) treatment. Methods Eighteen newly diagnosed CPP girls were enrolled. Body composition measured by bioelectrical impedance analysis and GnRH-A test were performed with fasting serum leptin, ghrelin and peptide YY (PYY) measurements at baseline (before) and after 20 weeks of GnRH-A treatment. Results Following GnRH-A treatment, all patients had prepubertal gonadotropin and estradiol levels. Mean (SD) fat mass index (FMI) was significantly increased from 4.5 (1.7) to 5.0 (1.8) kg/m2 after treatment. Also, median (IQR) serum leptin level was significantly increased from 6.9 (4.2–8.6) to 7.4 (5.3–13.1) ng/mL. FMI had a positive correlation with serum leptin level (r=0.64, p=0.004). In contrast, no significant changes of serum ghrelin and PYY levels were observed. Conclusions Decreased estrogen following short-term GnRH-A treatment in CPP girls may cause an increase in appetite and consequently an elevation of FMI. Increased serum leptin may be a result of having increased FMI secondary to an increase in appetite.

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