Kisspeptin-10 shows new lung, pregnancy, and cattle fertility effects

Researchers used a mouse model that mimics a severe form of asthma, where two types of immune inflammation, Th2 and Th17, are both active. This mixed type often responds poorly to standard treatments. The mice received Kisspeptin-10 through the nose before airway testing. The study found that acute exposure reduced airway hyperresponsiveness, the tendency of airways to tighten too easily. American Physiological Society

The Kisspeptin-10 research summary does not list respiratory effects, so this study adds a new area. It is also separate from the peptide's known vascular effects, which involve blood vessel constriction ⁴. The asthma finding suggests a different direction, but the study was small and only in mice.

Hypothyroidism during pregnancy can slow fetal growth and disturb the mother's metabolism. The study authors used rats made hypothyroid and treated some with Kisspeptin-10. They found that Kisspeptin-10 restored a key cell growth pathway in the placenta called mTOR signaling, and improved several markers of glucose regulation ². The mTOR pathway is a set of signals that controls cell growth and energy use, and it is often disrupted in pregnancies with poor fetal growth.

This builds on earlier work showing that Kisspeptin-10 can improve fetal and placental development in hypothyroid rats, but the new study adds the mTOR pathway and glucose mediators as specific mechanisms ². The existing page notes that placental kisspeptin is reduced in fetal growth restriction and pre-eclampsia, and that Kisspeptin-10 inhibits trophoblast invasion, which controls implantation depth ⁵. The new study extends that to a model of maternal thyroid disease.

Researchers compared Kisspeptin-10 and GnRH (gonadotropin-releasing hormone, the standard hormone used to trigger ovulation/synchronization) protocols for estrus synchronization, a process that brings heifers into heat at the same time for breeding. In 18 Sahiwal heifers, the kisspeptin-based protocol produced a stronger estrus response and an earlier onset of estrus than the standard GnRH protocol and a control group, without changing how long estrus lasted. DOI

This adds to earlier livestock data. In rabbits, Kisspeptin-10 induced ovulation in most animals ⁷. In sows, it matched GnRH on pregnancy outcomes ⁸. In cattle, previous work found that Kisspeptin-10 raised LH but did not reliably trigger ovulation during the luteal phase (the post-ovulation phase when the corpus luteum is active) at the doses tested ⁹. The new study suggests that in synchronization protocols, Kisspeptin-10 may be more effective than GnRH for bringing animals into estrus, at least in this breed.

These three studies sit at the edge of a field that has mostly focused on reproductive hormone release in humans. In healthy men, infusions raised LH, FSH, and testosterone ¹⁰, and in two women with cabergoline-resistant prolactinoma amenorrhea, 12-hour IV kisspeptin-10 restored LH pulses and reproductive hormone rises, though resumption of menses was not reported ¹². The new animal work adds respiratory, pregnancy metabolism, and livestock synchronization data, but none of it can yet be translated to human use.

For short-term effects, the asthma study measured airway response soon after dosing. For mid-term effects, the cattle study recorded estrus onset over a few days. For long-term effects, the pregnancy study tracked placental signaling across gestation. Across these time frames, the results are consistent in showing that Kisspeptin-10 can act outside the hypothalamic-pituitary-gonadal axis (the brain-to-ovary/testis hormone chain), but the evidence is still limited to animals.

No human asthma studies with Kisspeptin-10 exist, so whether the airway effect appears in people is unknown. The pregnancy study used a rat model of hypothyroidism; human pregnancy trials are absent. The cattle synchronization results may not apply to other breeds or to human fertility treatment. The dose and delivery in the asthma study, intranasal, is different from the infusion protocols used in human reproductive studies, so the comparison is not direct. The studies were not designed to test long-term safety or human outcomes.