The Vasoactive Potential of Kisspeptin-10 in the Peripheral Vasculature

Splice products of the Kiss1 protein (kisspeptins) have been shown to be involved in a diverse range of functions, including puberty, metastasis and vasoconstriction in large human arteries. Circulating Kisspeptin-10 (Kp-10) plasma levels are low in normal individuals but are elevated during various disease states as well as pregnancy. Here, we investigated the potential of Kp-10, the shortest biologically active kisspeptin, to influence microvascular effects, concentrating on the cutaneous vasculature. Kp-10 caused a dose-dependent increase in oedema formation (0.3–10nmol/injection site), assessed by Evans Blue albumin dye extravasation, in the dorsal skin of CD1 mice. Oedema formation was shown to be inhibited by the histamine H1 receptor antagonist mepyramine. The response was characterised by a ring of pallor at the injection site in keeping with vasoconstrictor activity. Therefore, changes in dorsal skin blood flow were assessed by clearance of intradermally injected 99mtechnetium. Kp-10 was found to significantly reduce clearance, in keeping with decreased blood flow and providing further evidence for vasoconstrictor activity. The decreased clearance was partially inhibited by co-treatment with the cyclo-oxygenase inhibitor indomethacin. Finally evidence for the kisspeptin receptor gene (Kiss1R), but not the kisspeptin peptide gene (Kiss1), mRNA expression was observed in heart, aorta and kidney samples from normal and angiotensin II induced hypertensive mice, with similar mRNA levels observed in each. We have evidence for two peripheral vasoactive roles for kisspeptin-10. Firstly, plasma extravasation indicative of ability to induce oedema formation and secondly decreased peripheral blood flow, indicating microvascular constriction. Thus Kp-10 has vasoactive properties in the peripheral microvasculature

Leukotriene B-4-Neutrophil Elastase Axis Drives Neutrophil Reverse Transendothelial Cell Migration In Vivo

This work was supported by generous funds from the Wellcome Trust (098291/Z/12/Z to S.N.). T.C. was supported by the ERC (ENDHORET). The work was also supported in part by funds from the William Harvey Research Foundation

Pallor inhibition ring at centre of kisspeptin mediated oedema increases in a dose dependent manner.

<p>Female CD1 mice were anaesthetised, injected with Evans Blue i.v. and treated intradermally in the dorsal skin with 0.3–10nmol Kp-10 (KP), 300pmol substance P (SP) or saline control (vehicle) in the dorsal skin. An uninjected site was also included (Un). Plasma extravasation was allowed to continue for 15 minutes. The skin was removed and the region in which oedema was inhibited (pallor area) measured. <i>N</i> = 6. Results are shown as mean area (mm²) ± SEM. * = p≤0.05, as assessed by one-way ANOVA compared to vehicle control.</p

Kisspeptin and Kiss1R expression does not alter after Angiotensin II treatment.

<p>C57BL/6 mice were treated with saline (white bars) or angiotensin II (Ang II, black bars) for 14 days. They were then killed and their hearts, kidneys and aortas removed before <i>Kiss1</i> (A) and <i>Kiss1R</i> (B) mRNA expression analysis. Results are displayed as mean copy number ± SEM normalised against HPRT-1, SDHA and PLA2 reference genes. <i>N</i> = 3 per group. No significant difference was observed between groups.</p

Kisspeptin-10 causes a dose-dependent increase in oedema formation in the cutaneous vasculature.

<p>Female CD1 mice were anaesthetised, injected with Evans Blue dye i.v. and treated intradermally in the dorsal skin with 0.3–10nmol kisspeptin-10 (KP), 300pmol substance P (SP) or saline control (Veh) for 30 minutes. An uninjected site was also included (Un). Plasma exudation was allowed to continue for 30 minutes post-injection at which point mice were killed, dorsal skin removed and the area of oedema measured (A). The lesion was also scored for colour intensity (B). Results are shown as mean area (mm²) ± SEM, <i>N</i> = 4. * = p≤0.05, ** = P≤0.01, *** = p≤0.001 assessed by one-way ANOVA compared to vehicle control.</p

Indomethacin inhibits kisspeptin-induced vasoconstriction.

<p>Female CD1 mice were anaesthetised, injected intradermally via the dorsal skin with 5% NaHCO₃/saline (Veh), 10nmol KP-10 (KP) or 30pmol Endothelin-1 (ET-1) in the presence or absence of 3nmol indomethacin (INDO), each containing an equal amount of ^99mTc. Clearance after ten minutes was assessed and compared to total radioactivity in an uninjected sample. Saline vehicle was adjusted to 100% and results displayed as a % change to controls. Results are shown as mean ± SEM, <i>N</i> = 6. * = p≤0.05 as assessed by one way ANOVA followed by a Bonferroni's post test.</p

Kisspeptin-10 decreases blood flow in the peripheral vasculature.

<p>Male and female CD1 mice were anaesthetised, injected intradermally via the dorsal skin with 3 or 10nmol KP-10 (KP) or 30pmol Endothelin-1 (ET-1), each containing an equal amount of ^99mTc. Clearance after ten minutes was assessed and compared to total radioactivity in an uninjected sample. Saline vehicle was adjusted to 100% and results displayed as a % change to controls. Results are shown as mean ± SEM, <i>N</i> = 5. * = p≤0.05, ** = p≤0.01 as assessed by two-tailed Student's t-test.</p

Kisspeptin induced oedema presents with a pallor ring at injection site in the dorsal skin.

<p>Female CD1 mice were anaesthetised, injected with Evans Blue i.v. and treated intradermally in the dorsal skin with 10pmol CGRP, 300pmol substance P (SP), 10nmol Kp-10 (K10), 10nmol Kp-10 +300pmol substance P (K + SP), 300pmol substance P +10pmol CGRP (SP + CGRP) or 10nmol Kp-10 +10pmol CGRP (K + CGRP). Plasma extravasation was allowed to continue for 30 minutes. Mice were killed, the dorsal skin removed and photographed. Pallor ring present in Kp-10 mediated oedema, but not under other conditions, is indicated.</p