Table 1. Summary of the studies that investigated the interaction between prolactin and kisspeptin.

Reference	Species	Comments
Presence of prolactin receptors in Kiss1-expressing neurons
Kokay and cols., 2011	Rat	86% of Kiss1-expressing neurons in the AVPV co-express PRLRs mRNA in OVX+E2 treated females 79% and 45% of Kiss1-expressing neurons in the ARH of OVX or OVX+E treated animals, respectively, co-express PRLRs mRNA
Li and cols., 2011	Sheep	60% of ARH kisspeptin immunoreactive neurons co-express PRLRs in OVX females
	Human	Not described
Evidence of responsiveness to prolactin
Brown and cols., 2014	Mouse	65% of kisspeptin immunoreactive neurons in the AVPV and 35% of kisspeptin neurons in the PeN express prolactin-induced pSTAT5 in mice in diestrus
Araujo-Lopes and cols., 2014	Rat	70-80% of ARH kisspeptin immunoreactive neurons express pSTAT5 after prolactin icv infusion (0.5 µg/2 µL) in virgin OVX or lactating animals
Sjoeholm and cols., 2011	Rat	65-75% of ARH kisspeptin neurons of primiparous rats co-express pSTAT5 after icv prolactin infusion (2.5 or 100 ng/rat)
Li and cols., 2011	Sheep	No co-expression between Kiss1 mRNA and prolactin-induced pSTAT5 (icv, 20 µg/hr/1 week) in the ARH of OVX+E2 females
	Human	Not described
Effects of prolactin on Kiss1 expression
Sonigo and cols., 2012	Mouse	Chronic infusion of prolactin (7 μg/24 hr/28 days) significantly decreases hypothalamic Kiss1 mRNA and kisspeptin immunoreactivity in the AVPV and ARH
Brown and cols., 2014	Mouse	3 sc doses of prolactin (100 µg/200 µg) cause a suppression of Kiss1 mRNA in the ARH of OVX mice
Araujo-Lopes and cols., 2014	Rat	Icv (4 µg/µL) or sc (0.5 mg/0.2 mL) prolactin injection causes a significant reduction of Kiss1 mRNA in the ARH of OVX rats
Li and cols., 2011	Sheep	Icv prolactin infusion (20 µg/hr/1 week) does not significantly change Kiss1 mRNA expression in the ARH of OVX+E2 females
	Human	Not described
Effects of kisspeptin on prolactin secretion
Szawka and cols., 2010	Rat/cell culture	Kisspeptin-10 icv infusion (3 nmol) increases serum prolactin release in OVX+E2 and proestrus females, but had no effect in OVX females, diestrus females or males Kisspeptin-10 does not alter prolactin secretion in anterior pituitary cell culture
Hashizume and cols., 2010	Goat	Intravenous administration of kisspeptin-10 (5 mg/kg) does not alter basal serum prolactin levels
Kadokawa and cols., 2008	Bovine/cell culture	Kisspeptin-10 (1 µM or 10 µM) increases media prolactin concentration of anterior pituitary cells, extracted from 8-month-old castrated male calves
Ramaswamy and cols., 2009	Monkey	Intravenous infusion of kisspeptin-10 (10 or 30 μg) induces no change in prolactin serum concentration in male Macaca mulatta
Jayasena and cols., 2014	Human	Acute or twice-daily for 1 week sc administration of kisspeptin-54 (6.4 nmol/kg) induced no effect on serum prolactin levels in healthy women