Cell-attached recording method showed that both NKB and senktide have a
Cell-attached recording method showed that both NKB and senktide have a potent stimulatory buy LY2510924 action on the firing of kisspeptin neurons derived from the ARC region of the mouse hypothalamus [14]. In ovariectomized goats, GnRH pulse generator activity at the ARC kisspeptin neurons, which was monitored by recording the multiple-unit activity in the hypothalamus, was stimulated after the intravenous injection of senktide [10]. It is suggested that small-amplitude release of LH (pulsatile LH secretion) is induced by the stimulatory action of NKB on the hypothalamic GnRH pulse generating system. The present study is the first trial to evaluate the use of NKB for the treatment of anestrus in goats. The obtained findings are limited because there was no untreated control group. In addition, the exact reasons for anestrus remain unclear, but it is likely that insufficient nutrition intake or other related factors such as stress might be attributed to the incidence of anestrus, as has been experimentally demonstrated in feed-restricted animals [15,16]. Consequently, most cases showed a therapeutic outcome; there was a gradual increase in E2 secretion followed by ovulation after the repetitive injections of senktide, at 4-h intervals for 24 h. However, the treatment was insufficientEndo and Tanaka BMC Research Notes 2014, 7:773 http://www.biomedcentral.com/1756-0500/7/Page 4 offor one goat (no.12) to stimulate follicular development, in spite of the increased LH stimulation caused by senktide treatment. One possible explanation for this is that the failure of follicular development and/or ovulation might be associated with the status of ovarian follicles during senktide treatment. According to ultrasonographic observation of ovaries during the estrous cycle in this species [17], ovulatory follicles appear from 5 days before ovulation and then grow to about 5 to 6 mm in diameter in parallel with the increase in the plasma E2 concentration. In addition to the fact that the anovulated goat (no.12) had only one follicle sized 2.7 mm in diameter on the day of treatment, the constantly low level of E2 (<5 pg/ml) also indicates the absence of steroidogenically active follicle(s) that can respond to LH stimulation. For optimal treatment of inactive ovary, the timing, duration and route of treatment seem to require adaptation according to the follicular and endocrine conditions. In one goat (no.9), a prominent increase in LH concentration close to those observed during the preovulatory PubMed ID:https://www.ncbi.nlm.nih.gov/pubmed/27663262 LH surge was observed following the first injection of senktide. A similar observation was reported from a study by Billings et al. [5], in which a surge-like increase in LH occurred after the treatment of senktide into the third ventricle in ewes during the follicular phase but not during the luteal phase. Although there may be limits to this pilot study as it is based one case, it seems likely that intravenous injection of senktide in a steroid milieu PubMed ID:https://www.ncbi.nlm.nih.gov/pubmed/27385778 similar to that present during the follicular phase of the cycle can generate a preovulatory GnRH/LH surge, as a trigger of ovulation. In conclusion, the present pilot study showed that intravenous treatment with senktide can stimulate LH secretion in anestrous goats, suggesting the potential value of NKB application in the treatment of reproductive disorders. The increased release of LH resulted in ovulation in most cases, except for one goat. This different outcome might be associated with the developmental and steroidogeni.