Effects of cholecystokinin on luteinizing hormone release from perifused hypothalamus-pituitary in the castrated bulls.

Kanematsu, Shigeto; Sato, Narichika; Hashizume, Takumi

doi:10.1262/jrd1977.36.54

Cited by 14 publications

(12 citation statements)

References 6 publications

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“…Plasma LH concentrations were measured by a doubleantibody radioimmunoassay procedure with slight modifications (Kanematsu et al 1990;Hashizume et al 1999). The standard preparation and the hormone for iodination were USDA-bLH-B-6 for LH.…”

Section: Hormone Assaymentioning

confidence: 99%

Kisspeptin‐10 stimulates the release of luteinizing hormone and testosterone in pre‐ and post‐pubertal male goats

Saito¹,

Sawada²,

Yaegashi³

et al. 2011

Animal Science Journal

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The aims of the present study were to clarify the effect of kisspeptin-10 (Kp10) on the secretion of luteinizing hormone (LH) and testosterone (T) in pre-pubertal and post-pubertal male ruminants. Four male goats (Shiba goats) were given an intravenous (i.v.) injection of Kp10 (5 µg/kg body weight (b.w.)), gonadotoropin-releasing hormone (GnRH, 1 µg/kg b.w.), or 2 mL of saline as a control at the ages of 3 (pre-pubertal) and 6 (post-pubertal) months. A single i.v. injection of Kp10 significantly stimulated the release of LH and T in both groups. The area under the response curve (AUC) of LH for a 60-min period after the i.v. injection of Kp10 was significantly greater in the pre-pubertal goats (P < 0.05). The AUC of T for a 120 min period post-injection did not differ between the two age groups. A single i.v. injection of GnRH also significantly stimulated the release of LH and T in both groups (P < 0.05). The secretory pattern of LH and T in response to GnRH resembled that in response to Kp10. These results show that the LH-releasing response to Kp10 is greater in pre-pubertal than post-pubertal male goats. They also show that Kp10, as well as GnRH, is able to stimulate the release of T in male goats.

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Section: Hormone Assaymentioning

confidence: 99%

Kisspeptin‐10 stimulates the release of luteinizing hormone and testosterone in pre‐ and post‐pubertal male goats

Saito¹,

Sawada²,

Yaegashi³

et al. 2011

Animal Science Journal

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“…LH was measured by a double-antibody radioimmunoassay as described elsewhere [15]. The LH standard preparation and hormone for iodination was USDA-ｂ LH-B-6 (USDA Animal Hormone Program, Beltsville, MD, USA).…”

Section: Hormone Assaysmentioning

confidence: 99%

Basal Levels and GnRH-induced Responses of Peripheral Testosterone and Estrogen in Holstein Bulls with Poor Semen Quality

Devkota

Takahashi²,

Matsuzaki³

et al. 2011

Journal of Reproduction and Development

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Abstract. The present study investigated the basal levels and GnRH-induced responses of peripheral testosterone and estrogen in Holstein bulls with poor semen quality. On the basis of semen parameters, bulls (n=5) having poor semen quality were selected as experimental bulls, and good semen quality bulls (n=4) were used as control bulls. Both groups were treated intramuscularly once with GnRH (250 μg of fertirelin acetate). Blood samples were collected at -1 day (d),-30 min and 0 h (treatment) followed by every 30 min for 5 h and 1, 3 and 5 d post-GnRH treatment (PGT), and LH, testosterone and estradiol-17β (E2) concentrations were measured. The pretreatment concentrations were used as basal levels. The percentage increments based on the 0-h levels were calculated per bull for each sampling time until 5 h PGT, and differences were compared between the experimental and control groups. The PGT concentrations of testosterone and basal and PGT concentrations of E2 were significantly lower in the experimental group. The testosterone increment in the experimental group was delayed and significantly lower from 1 to 5 h PGT than those in the control group. It can be suggested that bulls with poor semen quality have delayed and lower GnRH-induced testosterone response and may also have lower estrogen levels. Key words: Bull, Estrogen, GnRH-induced response, Poor semen quality, Testosterone (J. Reprod. Dev. 57: [373][374][375][376][377][378] 2011) ull fertility is very important because one bull may serve around twenty females under natural service conditions or hundreds of thousands under an artificial insemination program. Some bulls produce less or substandard quality spermatozoa, which results in a smaller number of inseminates and may also impair fertility postinsemination or postservice. The testes of such bulls are primarily characterized by mixed atrophied lesions, with abundant Sertoli cell-only tubules, in which the reversion of Sertoli cell maturity is possible [1]. However, it is difficult to understand their testicular physiology precisely and determine their future utilization.Different types of spermatogenic arrests leading to impaired fertility and their relationships with gonadotropic and gonadal steroid hormones have been described in men [2-4], rats [5] and bulls [6,7]. Although moderately predictable for the absolute fertility level, semen quality parameters of motility, sperm number and sperm morphology are valuable in identifying bulls of very low fertility [8]. The peripheral level of gonadotropins and testicular steroids may not be related to the testicular pathology in bulls, which points towards other abnormalities, including impaired gonadal responses to those hormones or secretion of intratesticular factors [7]. Some early studies have shown that the pituitary and testicular response with exogenous GnRH has no relation with semen production [9], sperm parameters [10] and libido [11] of bulls, while one study considered the testosterone response to GnRH to be a more reliable predictor of bull...

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“…Plasma LH, FSH and GH concentrations were measured by a double-antibody RIA procedure with slight modifications [24,25].…”

Section: Radioimmunoassay (Ria)mentioning

confidence: 99%

Characteristics of the Stimulatory Effect of Kisspeptin-10 on the Secretion of Luteinizing Hormone, Follicle-Stimulating Hormone and Growth Hormone in Prepubertal Male and Female Cattle

Ahmed

Saito

Sawada

et al. 2009

Journal of Reproduction and Development

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Abstract. The aims of the present study were to clarify the effect of kisspeptin-10 (Kp10) on the secretion of luteinizing hormone (LH), follicle-stimulating hormone (FSH) and growth hormone (GH) in prepubertal male and female cattle. The experiments were performed from May to June using five male (4-6 months old) and five female (5-6 months old) Japanese Black calves. A single intravenous (iv) injection of Kp10 (5 μg/kg body weight (b.w.): 3.85 nmol/ kg b.w.)significantly stimulated the release of LH and FSH in male and female calves (P<0.05). A single intramuscular injection of Kp10 (5 μg/kg b.w.) also significantly stimulated the release of LH and FSH in male calves (P<0.05), though the response was smaller than that to the iv injection. The injection of Kp10 did not alter the basal plasma concentration of GH in male or female calves. The area under the curve (AUC) of both LH and FSH for a 120-min period after the iv injection of Kp10 was significantly greater in the males than females (P<0.05). These results show that Kp10 can stimulate the release of LH and FSH in calves of both sexes and that the response to the peptide is greater in males at this age. They also show that Kp10 has no effect on the release of GH in male and female calves and that the LH-and FSHreleasing effect of Kp10 is greater after an iv injection than after an im injection in calves. Key words: Cattle, Follicle-stimulating hormone (FSH), Growth hormone (GH), Kisspeptin-10, Luteinizing hormone (LH) (J. Reprod. Dev. 55: 650-654, 2009) he pituitary's release of gonadotropins, luteinizing hormone (LH) and follicle-stimulating hormone (FSH), is essential to normal gonadal development and function [1], such as ovulation in females and spermatogenesis in males [2]. The brain-pituitarygonadal axis is operated by the decapeptide gonadotropin-releasing hormone (GnRH) in the mammalian brain. However, recently, the KiSS-1/GPR54 system in the hypothalamus was implicated in the regulation of this axis [3][4][5].Kisspeptin is the product of the KiSS-1 gene, which encodes a 145-amino acid peptide that is further processed to generate biologically active peptides of various lengths (10-54 amino acids) termed kisspeptins [5,6]. Kisspeptin neurons are found in the hypothalamus [7][8][9], and kisspeptins strongly stimulate the secretion of gonadotropin through a G protein-coupled receptor known as GPR54 [3][4][5]. The actions of these peptides are thought to involve mainly stimulating GnRH's neuronal activity through GPR54 [3][4][5].An administration of kisspeptin, either centrally or peripherally, has been shown to elicit the release of gonadotropins in ruminants [10][11][12][13][14][15] as well as in rats [16,17], pigs [18], monkeys [19] and humans [20,21]. However, in cattle, only two in vivo studies have been conducted [13,14], and the precise effects of kisspeptin on the secretion of pituitary hormones under physiological conditions are unknown.Puberty as a successful reproductive event is closely related to interactions between the gonadotropic axis ...

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Effects of cholecystokinin on luteinizing hormone release from perifused hypothalamus-pituitary in the castrated bulls.

Cited by 14 publications

References 6 publications

Kisspeptin‐10 stimulates the release of luteinizing hormone and testosterone in pre‐ and post‐pubertal male goats

Kisspeptin‐10 stimulates the release of luteinizing hormone and testosterone in pre‐ and post‐pubertal male goats

Basal Levels and GnRH-induced Responses of Peripheral Testosterone and Estrogen in Holstein Bulls with Poor Semen Quality

Characteristics of the Stimulatory Effect of Kisspeptin-10 on the Secretion of Luteinizing Hormone, Follicle-Stimulating Hormone and Growth Hormone in Prepubertal Male and Female Cattle

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