Kisspeptin Modulates Luteinizing Hormone Release and Ovarian Follicular Dynamics in Pre-pubertal and Adult Murrah Buffaloes

Abstract

Kisspeptin is a neuropeptide that governs the reproductive axis upstream to GnRH. We wanted to study whether kisspeptin modulates plasma LH and FSH levels and ovarian follicular dynamics in buffaloes and whether kisspeptin can be used for fixed time artificial insemination (FTAI). We carried out these studies in comparison with buserelin, a potent GnRH agonist. Kisspeptin dose-dependently increased plasma LH levels. However, the kisspeptin-induced increase in LH was short-lived as the peak reached in 15–30 min returned to basal values by 1–2 h. The kisspeptin-induced increase in LH level was less compared to buserelin-induced increase in LH level which sustained over time. Kisspeptin did not enhance FSH release while buserelin resulted in a gradual increase over time. LH response to repeated injections of kisspeptin was greater than that induced by buserelin. While buserelin induced an increase in the number of follicles, kisspeptin induced an increase in the growth rate of the follicle. In adult cycling animals, while both the drugs increased plasma LH levels, the increase was greater in buserelin group compared to kisspeptin group. In contrast to the findings in pre-pubertal animals, kisspeptin induced an increase in both the number as well as the size of follicles compared to buserelin. Our studies on oestrus synchronization, using either kisspeptin-PGF2α-kisspeptin protocol or buserelin-PGF2α-buserelin Ovsynch protocol on day 0, 7, and 9, respectively, revealed that kisspeptin increased the number of follicles at wave emergence and the diameter of dominant follicle after 2nd dose of drug, the oestrus response rate and duration of oestrus, compared to buserelin. However, conception rate was not significantly different among the groups. From our studies, it appears that Kp and Buserelin differentially modulate follicular dynamics depending on the reproductive age of the animals.However, studies in a larger herd are required to confirm whether kisspeptin can be used for oestrous synchronization in buffaloes.

Kisspeptin regulates the development of caprine primordial follicles in vitro

“…Though most of the studies have emphasized the anti-angiogenic effect of kisspeptin, especially during tumour growth, a few studies have shown that kisspeptin increases migration and proliferation of endothelial cells, the components of angiogenesis (Golzar and Javanmard, 2015). Facilitation by kisspeptin of ovarian follicular growth has been observed in vivo in livestock species (Pottapenjera et al, 2018). The current study supports the in vivo observation and further suggests a direct action of kisspeptin on ovaries rather than indirect effects via release of gonadotropins.…”

Role of Kisspeptin on the reproductive system of livestock and pet animals

“…The LH surge is increased due to the administration of Kp but no longer sustains the peak and the Kp is enhance the follicular growth and a follicular number of the Murrah buffalos up on the age of animals (Pottapenjera et al, 2018) [17] . The Kp and Kp1r expression can change the follicular development stage of the estrous cycle and expression is higher in the case of cyclic compared to the acyclic buffaloes.…”

“…Exogenous injection of Kp in different modes can enhance the release of gonadotrophin of LH in a number of species. The kp neurons act on the GnRH and activate for secretion of gonadotrophin in Mice (Messager et al, 2005) [7] , Gilts (Lents et al, 2008) [8] , Mare (Wilborn et al, 2008) [10,34] , Cattle (Ezzat et al, 2010) [9,42] , Goats (SAITO et al, 2011) [11] , Men (George et al, 2011) [12] , Women (Dhillo et al, 2007; Jayasena et al, 2014) [14,15] , Ewes (Wang et al, 2012) [13] , Dogs (Albers-Wolthers et al, 2014) [16] , Buffalo (Pottapenjera et al, 2018) [17] . The kp and its receptor are expressed in the ovaries of many species (Roman et al, 2012;Hu et al, 2017;Terao et al, 2004;Iwata et al, 2017) [18,19,20,21] , mainly expressed in granulosa cells of rats and predominantly expressed in mice oocytes (Chakravarthi et al, 2018) [22] .…”

Peripheral action of kisspeptin at reproductive tissues—role in ovarian function and embryo implantation and relevance to assisted reproductive technology in livestock: a review

“…The latter finding led to the suggestion that KISS1 agonists may have potential in the management of puberty in livestock. In this regard, KISS-10 induced gonadotropin secretion and influenced ovarian function in prepubertal buffalo [ 183 ], cattle [ 180 ], sheep [ 186 , 187 ], and pigs [ 177 , 188 ]. KISS-10 also induced gonadotropin secretion and ovulation in seasonally anestrous ewes [ 189 , 190 ] and synchronized ovulation in goats [ 79 ].…”