Differential regulation of the secretion of luteinizing hormone and follicle-stimulating hormone around the time of ovulation in the bitch

Gier, J. De; Kooistra, H.S.; Djajadiningrat-Laanen, S.C.; Dieleman, S.J.; Okkens, A.C.

doi:10.1016/j.theriogenology.2006.02.001

Cited by 9 publications

(9 citation statements)

References 19 publications

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“…The concentration of oestradiol, which is mainly synthesized and secreted by granulosa cells in developing ovarian follicles, rises during this phase and reaches peak levels around the pre‐ovulatory luteinizing hormone (LH) surge (Olson et al. 1982; Schaefers‐Okkens 2005; De Gier et al. 2006).…”

Section: Introductionmentioning

confidence: 99%

Effects of Gonadotrophin Releasing Hormone Administration on the Pituitary‐Ovarian Axis in Anoestrous vs Ovariectomized Bitches

Buijtels¹,

Beijerink²,

Kooistra³

et al. 2006

Reprod Domestic Animals

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ContentsThe aim of this study was to determine the effects of gonadotrophin releasing hormone (GnRH) administration on the plasma concentrations of reproductive hormones in intact and ovariectomized (OVX) bitches. Therefore, blood samples were collected at multiple times before and after the administration of 10 lg/kg GnRH (FertagylÒ) for the determination of the plasma concentrations of luteinizing hormone (LH), oestradiol, progesterone and testosterone in six anoestrus and in six OVX bitches. The mean plasma LH concentrations before and 60 min after GnRH administration were significantly lower in the anoestrous bitches than in the OVX bitches. In both groups GnRH administration resulted in a significant increase in the plasma LH concentration. The highest plasma LH concentrations were found at 10 min after GnRH administration and these values did not differ significantly between the two groups. Only in the anoestrous bitches a significant increase in plasma oestradiol concentrations was found after GnRH administration and these values were significantly higher than those in the OVX bitches. The plasma concentrations of progesterone and testosterone were low (close to or below the limit of quantitation) both before and after GnRH administration and the differences between anoestrous and OVX bitches were not significant. It can be concluded that (i) basal plasma LH concentration is significantly higher in OVX bitches than in anoestrous bitches, (ii) plasma LH concentration increases after GnRH administration in both anoestrous and OVX bitches, (iii) GnRH administration causes a significant rise in plasma oestradiol concentration only if ovarian tissue is present and (iv) measurement of plasma progesterone and testosterone concentrations before and after GnRH administration does not aid in distinguishing between anoestrous and OVX bitches. The results of this study may provide a basis for the diagnosis of remnant ovarian tissue and verification of neuter status in the bitch.

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Section: Introductionmentioning

confidence: 99%

Effects of Gonadotrophin Releasing Hormone Administration on the Pituitary‐Ovarian Axis in Anoestrous vs Ovariectomized Bitches

Buijtels¹,

Beijerink²,

Kooistra³

et al. 2006

Reprod Domestic Animals

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“…In the dog, FSH pulses appear to occur concomitantly with LH pulses in all stages of the oestrous cycle and anoestrus (Kooistra et al 1999a). Yet, differential regulation of FSH and LH has also been reported in this species, both during anoestrus and during the follicular phase and the period of ovulation and fertilization (Kooistra et al 1999a;De Gier et al 2006). Differential regulation of FSH and LH secretion can at least partly be explained by the frequency and amplitude of GnRH pulses (Haisenleder et al 1991;Vizcarra et al 1997).…”

Section: Hypothalamic-pituitary-ovarian Axismentioning

confidence: 83%

“…Yet, differential regulation of FSH and LH has also been reported in this species, both during anoestrus and during the follicular phase and the period of ovulation and fertilization (Kooistra et al. 1999a; De Gier et al. 2006).…”

Section: Introductionmentioning

confidence: 82%

Anoestrus in the Dog: a Fascinating Story

Okkens

Kooistra

2006

Reprod Domestic Animals

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In the bitch, progression from early to late anoestrus is characterized by a higher amplitude and a larger number of gonadotrophin-releasing hormone (GnRH) pulses generated by the hypothalamus, an increase in the sensitivity of the pituitary to GnRH, and an increase in ovarian responsiveness to gonadotrophins. An increase in basal plasma follicle-stimulating hormone (FSH) concentration is a critical event required for initiation of folliculogenesis. A period of increased luteinizing hormone pulsatility has been reported shortly before the onset of pro-oestrus. Apart from these changes in the hypothalamic-pituitary-ovarian axis, there is also involvement of dopaminergic influences in the initiation of a new follicular phase in the bitch. Administration of the dopamine-agonists bromocriptine and cabergoline shortens the anoestrus and is associated with a decrease in the plasma prolactin concentration, suggesting that the shortened anoestrus is the result of suppression of prolactin secretion. Yet, the anoestrus is not shortened in bitches treated with metergoline, a drug, which in a low dosage lowers the plasma prolactin concentration via a serotonin-antagonistic pathway. In addition, under physiological conditions low plasma prolactin concentrations are found during the entire anoestrus. Furthermore, a low dosage of bromocriptine, insufficient to cause a decrease in the plasma prolactin concentration, prematurely induces folliculogenesis. These observations indicate that not the decrease in the plasma prolactin concentration, but another dopamine-agonistic influence plays a critical role in the transition to a new follicular phase. The dopamine-agonist induced shortening of the anoestrus is associated with a rapid rise in the basal plasma FSH concentration, similar to what is observed during the physiological late anoestrus. This observation underlines the importance of an increase in the circulating plasma FSH concentration in the initiation of folliculogenesis in the bitch.

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“…Therefore, a combined use of these methods is recommended. The multiple method, vaginal cytology + P4 testing + LH hormone concentration and USG if necessary, is regarded the current gold standard for accuracy in predicting the time of ovulation (1,5,8,11). When quick results in the field are demanded, a one-alone method such as VEI can be used.…”

Section: Praca Oryginalnamentioning

confidence: 99%

“…al. (5). The analyses were performed with the electrochemiluminescence immunoassay (ECLIA) method by using a Roche E170 modular device (5).…”

Section: Animalsmentioning

confidence: 99%

Efficiency of vaginal electrical impedance to determine the stage of the reproductive cycle in bitches

Gürler¹,

Koldaş²,

Önyay³

et al. 2018

Medycyna Weterynaryjna

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SummaryA study was carried out to compare the efficiency of vaginal electrical impedance with serum progesterone profile, cytological examination and clinical findings. Vaginal electrical impedance values varied at the different stages of the estrous cycle, with the highest value during the transition into estrous and the lowest in diestrus (P < 0.05). There was a negative statistical correlation between serum progesterone values and the impedance values (36%) (P < 0.001). Vaginal electrical impedance was a faster and cheaper method than progesterone assessment. It was more reliable than vaginal cytology and clinical evaluation. In conclusion, a combination of vaginal electrical impedance measurements and progesterone evaluation was a more useful method for determination of the optimal breeding time in bitches.

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Differential regulation of the secretion of luteinizing hormone and follicle-stimulating hormone around the time of ovulation in the bitch

Cited by 9 publications

References 19 publications

Effects of Gonadotrophin Releasing Hormone Administration on the Pituitary‐Ovarian Axis in Anoestrous vs Ovariectomized Bitches

Effects of Gonadotrophin Releasing Hormone Administration on the Pituitary‐Ovarian Axis in Anoestrous vs Ovariectomized Bitches

Anoestrus in the Dog: a Fascinating Story

Efficiency of vaginal electrical impedance to determine the stage of the reproductive cycle in bitches

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