Kisspeptin has recently emerged as a key regulator of the mammalian reproductive axis. It is known that kisspeptin, acting centrally via the kisspeptin receptor, stimulates secretion of gonadotrophin releasing hormone (GnRH). Loss of kisspeptin signaling causes hypogonadotrophic hypogonadism in humans and other mammals. Kisspeptin interacts with other neuropeptides such as neurokinin B and dynorphin, to regulate GnRH pulse generation. In addition, a growing body of evidence suggests that kisspeptin signaling be regulated by nutritional status and stress. Kisspeptin may also represent a novel potential therapeutic target in the treatment of fertility disorders. Early human studies suggest that peripheral exogenous kisspeptin administration stimulates gonadotrophin release in healthy adults and in patients with certain forms of infertility. This review aims to concisely summarize what is known about kisspeptin as a regulator of reproductive function, and provide an update on recent advances within this field.
Adult ; Dynorphins ; Fertility ; Gonadotropin-Releasing Hormone ; Humans ; Hypogonadism ; Hypothalamus ; Infertility ; Kisspeptins ; Mammals ; Neurokinin B ; Neuropeptides ; Nutritional Status ; Axis, Cervical Vertebra

BACKGROUND AND OBJECTIVES: Osteoclasts are the principal cell of bone resorption playing a major role in focal bone erosion associated with cholesteatoma. This study was conducted in order to investigate direct effect of substance P (SP) on osteoclastogenesis and osteoclastic bone resorption in vitro. MATERIALS AND METHOD: SP dose response was measured in receptor activator for NF-kappaB ligand (RANKL)-induced mouse osteoclast culture and osteoclastic bone resorption assay. RT-PCR was performed for the expression of neurokinin(NK) receptor mRNAs in osteoclasts. RESULTS: Treatment with SP (100 nM and 1000 nM) significantly increased osteoclastogenesis. SP (0.1 nM and 1 nM) significantly increased resorption surface area on dentin slices by osteoclasts. Cultured osteoclasts expressed NK-2 receptor mRNA. CONCLUSION: SP has a direct upregulatory effect on osteoclastogenesis and osteoclastic bone resorption that is mediated possibly by NK-2 receptor.
Animals ; Bone Resorption* ; Cholesteatoma ; Dentin ; Mice ; NF-kappa B ; Osteoclasts* ; Receptors, Neurokinin-2 ; RNA, Messenger ; Substance P*

<b>OBJECTIVEb>To explore the effects of obesity on the peak level of luteinizing hormone (LH) in the gonadotropin-releasing hormone (GnRH) agonist test and obesity-related hormones in girls with central precocious puberty (CPP).

<b>METHODSb>Three hundred and thirty-three girls with CPP who underwent the GnRH agonist test between 2012 and 2014 were classified into three groups: normal weight (n=123), overweight (n=108), and obesity (n=102), according to body mass index (BMI). The sexual development indices were compared between the three groups. Twenty girls were randomly selected from each group for evaluation of the serum levels of leptin, sex hormone binding globulin (SHBG), neurokinin B, and kisspeptin. The correlation of BMI with the levels of various hormones was assessed using Pearson correlation analysis.

<b>RESULTSb>There was no significant difference in mean age at diagnosis between the three groups; however, the bone age was significantly higher in the overweight and obesity groups than in the normal weight group (P<0.05). The peak level of LH in the GnRH agonist test and SHBG level in the normal weight group were significantly higher than those in the overweight and the obesity groups, while the serum levels of leptin and neurokinin B were significantly lower in the normal weight group than in the overweight and the obesity groups (P<0.05). BMI was negatively correlated with the peak level of LH in the GnRH agonist test and SHBG level (P<0.05), and positively correlated with the levels of leptin and neurokinin B (P<0.05).

<b>CONCLUSIONSb>The effects of BMI on the result of the GnRH agonist test and levels of obesity-related hormones should be taken into account in girls with precocious puberty.

Body Mass Index ; Child ; Female ; Gonadotropin-Releasing Hormone ; agonists ; Humans ; Leptin ; blood ; Luteinizing Hormone ; blood ; Neurokinin B ; blood ; Obesity ; blood ; Puberty, Precocious ; blood ; Sex Hormone-Binding Globulin ; analysis

BACKGROUND: Asthma is an inflammatory disease because there are many inflammatory changes in the asthmatic airways. Axon reflex mechanisms may be involved in the pathogenesis of asthma. Sensory neuropeptides are involved in this inflammation, which is defined as neurogenic inflammation. Substance p, neurokinin A, and neurokinin B may be main neuropeptides of neurogenic inflammation in airways. These tachykinins act on neurokinin recptors. Three types of neurokinin receptors, such as NK1, NK2, and NK3, are currently recognized, at which substance p,neurokinin A, and neurokinin B may be the most relvant natural agonist of neurogenic inflammation in airways. The receptor subtypes present in several tissues have been characterized on the basis of differential sensitivity to substance p, neurokinin A, and neurokinin B. Plasma extravasation and vasodilation are induced by substance p more potently than by neurokinin A, indicating NK1 receptors on endothelial cells mediate the response. But airway contraction is induced by neurokinin A more potently than by substance P, indicating the NK2 receptors in airway smooth muscles. These receptors are used to evaulate the pathogenesis of brochial asthma. FK224 was identified from the fermentation products of Streptomyces violaceoniger. FK224 is a dual antagonist of both NK1 and NK2 recptors. PURPOSE: For a study of pathogenesis of bronchial asthma, the effect of FK224 on plasma extravasation induced by vagal NANC electrical stimulation was evaluated in rat airway. METHOD: Male Sprague-Dawley rats weighing 180~450gm were anesthetized by i.p. injection of urethane. Plasma extravasation was induced by electrical stimulation of cervical vagus NANC nerves with 5Hz, 1mA, and 5V for 2 minutes(NANC2 group) and for sham operation without nerve stimulation(control group). To evaluate the effect of FK224 on plasma extravasation in neurogenic inflammation, FK224(lmg/kg, Fujisawa Pharmaceutical Co., dissolved in dimethylsul- phoxide; DMSO, Sigma Co.) was injected 1 min before nerve stimulation(FK224 group). To assess plasma exudation, Evans blue dye(20mg/kg,dissolved in saline) was used as a plasma marker and was injected before nerve stimulation. After removal of intravascular dye, the evans blue dye in the tissue was extracted in formamide(37degreesC, 24h) and quantified spectrophotometrically by measuring dye absorbance at 629nm wavelength. Tissue dye content was expressed as ng of dye per mg of wet weight tissue. The amount of plasma extravasation was measured on the part of airways in each groups. RESULTS: 1) Vagus nerve(NANC) stimulation significantly increased plasma leakage in trachea, main bronchus, and peripheral bronchus compared with control group, 14.1 +/-1.6 to 49.7+/-2.5, 17.5 +2.0 to 38.7 +/-2.8, and 12.7+/-2.2 to 19.1 +/-1.6ng of dye per mg of tissue(mean +/- SE), respectively(p< 0.05). But there was not significantly changed in lung parenchyma(p >0.05) 2) FK224 had significant inhibitory effect upon vagal nerve stimulation-induced airway plasma leakage in any airway tissues of rat,such as trachea, main bronchus, and peripheral bronchus compared with vagus nerve stimulation group, 49%, 58%, and 70%, respectively(p<0.05). Inhibitory effect of FK224 on airway plasma leakage in neurogenic inflammation was revealed the more significant in peripheral bronchus, but no significant in lung parenchyma. CONCLUSION: These results suggest that FK224 is a selective NK receptor antagonist which effectively inhibits airway plasma leakage induced by the endogenous neurotransmitters relased by neurogenic inflammation in rat airway. Tachykinin receptor antagonists may be useful in the treatment of brochial asthma.
Animals ; Asthma ; Axons ; Bronchi ; Dimethyl Sulfoxide ; Electric Stimulation ; Endothelial Cells ; Evans Blue ; Fermentation ; Humans ; Inflammation ; Lung ; Male ; Muscle, Smooth ; Neurogenic Inflammation* ; Neurokinin A ; Neurokinin B ; Neuropeptides ; Neurotransmitter Agents ; Plasma* ; Rats* ; Rats, Sprague-Dawley ; Receptors, Tachykinin ; Reflex ; Streptomyces ; Substance P ; Tachykinins ; Trachea ; Urethane ; Vagus Nerve Stimulation ; Vasodilation