Table 3.
Effect of GnIH on the HPG axis of amphioxus, lamprey, and teleost fishes.
| In vitro (cell line or pituitary) or in vivo (animal) | Concentration or dose of peptides | Culture medium, rout of administration | Administration time, sample collection, measurement | Effect | Reference |
|---|---|---|---|---|---|
| In vivo | |||||
| European sea bass | 1, 2, 4 µg sea bass GnIH-1, 2 | icv | 6 h after administration brain, pituitary, and blood were collected | GnRH1 mRNA level in the brain was decreased by 1, 2, 4 µg GnIH-1. GnRH2 mRNA level in the brain was decreased by 1, 2, 4 µg GnIH-2. Kiss1 mRNA level in the brain was decreased by 2-µg GnIH-2. Kiss2 mRNA level in the brain was decreased by 2, 4 µg GnIH-2. Kiss1 receptor mRNA level in the brain was decreased by 2-µg GnIH-2. GnIH mRNA level in the brain was decreased by 1, 2 µg GnIH-2. GnIH receptor mRNA level in the brain was decreased by 1, 2 µg GnIH-2. LHβ mRNA level in the pituitary was decreased by 1, 2, 4 µg GnIH-2. FSHβ mRNA level in the pituitary was decreased by 2, 4 µg GnIH-2. GnRH receptor II1a mRNA level in the pituitary was decreased by 2, 4 µg GnIH-2. Plasma LH level was decreased by 4-µg GnIH-1 and 1-µg GnIH-2 | Paullada-Salmerón et al. (73) |
| Goldfish | 2-µg goldfish LPXRFa-3 | ip | Injected twice with 12-h interval and pituitaries and blood were collected 12 h after the second injection | LHβ mRNA level was increased at early to mid-late gr. FSHβ mRNA levels was increased at early to late gr. Serum LH concentration was decreased at early to mid-gr | Moussavi et al. (71) |
| Goldfish | 2-µg goldfish LPXRFa-3 | ip | Injected twice with 12-h interval with or without 4-µg sGnRH or cGnRH-II and pituitaries and blood were collected 2 h after the second injection | LHβ level was increased by LPXRFa-3 at early to mid-gr. FSHβ mRNA levels was increased LPXRFa-3 at early to late gr. Serum LH concentration was decreased by LPXRFa-3 at early to mid-gr. LHβ mRNA level increased by sGnRH was decreased by LPXRFa-3 at early to late gr. LHβ level increased by cGnRH-II was decreased by LPXRFa-3 at mid to late gr. FSHβ mRNA level increased by sGnRH was decreased by LPXRFa-3 at mid to late gr | Moussavi et al. (72) |
| Sexually mature female goldfish | 1-µg/g bw zebrafish LPXRFa-3 | ip | Injected twice with 3-h interval and blood was collected 1 and 3 h after the second injection | Serum LH concentration was decreased by LPXRFa-3 either at 1 and 3 h after the second injection | Zhang et al. (74) |
| Female goldfish at late vitellogenic stage | 100-ng/g bw goldfish LPXRFa-2, 3 | ip | After 12-h administration hypothalamus and pituitary were collected | sGnRH mRNA level in the hypothalamus was decreased by LPXRFa-2, 3. LHβ mRNA level in the pituitary was decreased by LPXRFa-2. FSHβ mRNA level in the pituitary was decreased by LPXRFa-2, 3 | Qi et al. (75) |
| Immature, mature male and female cinnamon clownfish | 100-ng/g bw goldfish LPXRFa-3 | ip | After 0, 6, 12, and 24-h administration with or without 100-ng/g bw sbGnRH brain, pituitary and blood were collected | GnIH and GnIH receptor mRNA levels in the brain were increased at 6, 12 and 24 h.a GnIH and GnIH receptor mRNA levels in the brain decreased by sbGnRH were increased at 6, 12 and 24 h.a sbGnRH mRNA level in the brain, plasma GnRH, FSH, LH levels, pituitary GTHα, FSHβ, LHβ mRNA levels were decreased at 6, 12 and 24 h.a sbGnRH mRNA level in the brain, plasma GnRH, FSH, LH levels, pituitary GTHα, FSHβ, LHβ mRNA levels increased by sbGnRH were decreased at 6, 12 and 24 ha | Choi et al. (76) |
| Female orange-spotted grouper | 100-ng/g bw grouper GnIH-I, II, III | ip | Injected twice with 6-h interval and hypothalamus and pituitary were collected 6 h after the second injection | GnRH1 mRNA level in the hypothalamus was decreased by grouper GnIH-I, II, III. GnRH3 mRNA level in the hypothalamus was increased by grouper GnIH-III. LHβ mRNA level in the pituitary was decreased by grouper GnIH-II | Wang et al. (77) |
| Lamprey | 50, 100 µg/kg bw lamprey LPXRFa-1a, 1b, 2 | ip | Injected twice with 24-h interval and brain and pituitary were collected 48 h after the second injection | Lamprey GnRH-I, III content in the brain, gonadotropin β mRNA level in the pituitary were increased by 100-µg/kg bw LPXRFa-2 | Osugi et al. (20) |
| European sea bass | 1-µg sea bass GnIH-1, 2/g bw in coconut oil | im | Injected on day 17 from October to January and blood was collected on day 22 from October to January. Brain and pituitary were collected on day 17 of February (spermiation stage) | Plasma testosterone and 11-ketotestosterone levels were decreased by sbGnIH-1, 2 in November and December (early and mid-spermatogenesis). GnRH2, sbGnIH, sbGnIH receptor, kiss1 receptor mRNA levels in the brain were increased by sbGnIH-2. LHβ mRNA level in the pituitary was decreased by sbGnIH-1 and -2. Plasma FSH level was decreased by sbGnIH-1. Plasma LH level was decreased by sbGnIH-1 and -2 | Paullada-Salmerón et al. (27) |
| Flatfish | 0.1, 1 µg/g bw flatfish GnIH-2, 3 | im | Injected twice with 12-h interval and brain and pituitary were collected 4 and 8 h after the second injection | GnRH3 mRNA level in the brain was decreased by 1-µg/g bw GnIH-3 at 4 h after administration. LHβ mRNA level in the pituitary was decreased by 0.1, 1 µg/g bw GnIH-3 at 4 h after administration | Aliaga-Guerrero et al. (78) |
| In vitro | |||||
| Primary culture of male zebrafish pituitary | 10−12, 10−11, 10−10, 10−9 M zebrafish LPXRFa-3 | Culture media | After 18-h incubation pituitary was collected | Common α mRNA level was decreased by 10−12, 10−11, 10−10 M LPXRFa-3. LHβ mRNA level was decreased by 10−11, 10−10 M LPXRFa-3 | Spicer et al. (60) |
| Primary culture of grass puffer pituitary | 10−9, 10−7 M goldfish LPXRFa-1 | RPMI medium | After 48-h administration pituitaries were collected | LHβ, FSHβ mRNA levels were increased by 10−7 M LPXRFa-1 | Shahjahan et al. (79) |
| Primary culture of Cichlasoma dimerus pituitary | 10−8, 10−6 M Cichlasoma dimerus LPQRFa-1, -2 | Leibovitz L-15 medium with 10% fetal bovine serum | After 24-h incubation medium was collected | LH and FSH concentration was decreased by 10−6 M LPQRFa-1. FSH concentration was increased by 10−6 M LPQRFa-2 | Di Yorio et al. (80) |
| Primary culture of male Nile tilapia pituitary | 10−9, 10−8, 10−7, 10−6 M Pyroglutamic-tilapia LPXRFa-2 | Culture medium | After 6-h incubation medium was collected | LH concentration was increased by 10−7, 10−6 M pyroglutamic-LPXRFa-2. FSH concentration was increased by 10−6 M pyroglutamic-LPXRFa-2 | Biran et al. (81) |
| Dispersed goldfish pituitary cells | 10−9, 10−8, 10−7 M goldfish LPXRFa-3 | Medium 199 with 1% horse serum | After 12-h administration medium and cells were collected | LHβ mRNA level was decreased by 10−8 and 10−7 M LPXRFa-3 at early gr, increased by 10−9 M LPXRFa-3 at mid-gr, decreased by 10−8 and 10−7 M LPXRFa-3 at late gr. FSHβ mRNA levels was decreased by 10−8 and 10−7 M LPXRFa-3 at early gr, by 10−9, 10−8, 10−7 M LPXRFa-3 at mid-gr, by 10−7 M LPXRFa-3 at late gr. LH concentration in the media was increased by 10−8 M LPXRFa-3 at late gr | Moussavi et al. (71) |
| Dispersed female goldfish pituitary cells | 10−7 M goldfish LPXRFa-2, 3 | Medium 199 with 10% fetal bovine serum | After 12-h administration with 10−7 M LHRH-A cells were collected | FSHβ mRNA level increased by LHRH-A was decreased by 10−7 M LPXRFa-3. | Qi et al. (75) |
| Dispersed male sockeye salmon pituitary cells | 10−9, 10−7, 10−5 M goldfish LPXRFa-1, 2, 3 | MEM | After 2-h administration medium was collected | LH concentration in the media was increased by 10−7 and 10−5 M LPXRFa-1, 2, and 10−9, 10−5 M LPXRFa-3. FSH concentration in the media was increased by 10−9 and 10−5 M LPXRFa-1, 10−7, 10−5 M LPXRFa-2, and 10−7 M LPXRFa-3 | Amano et al. (66) |
| COS-7 cells transfected with orange-spotted grouper GnIH receptor | 10−10, 10−9, 10−8, 10−7, 10−6 M grouper GnIH-I, -II, -III | DMEM with 10% fetal bovine serum | After 24-h incubation CRE or SRC-luciferase activity was measured | Forskolin-induced CRE-luciferase activity was decreased by 10−9, 10−8, 10−7, 10−6 M grouper GnIH-I, II and 10−6 M grouper GnIH-III. SRE-luciferase activity was decreased by 10−9, 10−7, 10−6 M grouper GnIH-I | Wang et al. (77) |
| COS-7 cells transfected with amphioxus PQRFa receptor 1 | 10−7, 10−6 M amphioxus PQRFa-1, 2, 3 | DMEM | After 6-h administration CRE-luciferase activity was measured | Forskolin-induced CRE-luciferase activity was decreased by 10−6 M PQRFa-1, 2, and 10−7, 10−6 M PQRFa-3 | Osugi et al. (21) |
bw, body weight; cGnRH-II, chicken GnRH-II; CRE, cAMP response elements; DMEM, Dulbecco’s modified Eagle’s medium; FSH, follicle-stimulating hormone; gr, gonadal recrudescence; icv, intracerebroventricular administration; im, intramuscular administration; ip, intraperitoneal administration; LH, luteinizing hormone; LHRH-A, [D-Ala6, Pro9 NEt]-LHRH; MEM, minimum essential medium; sGnRH, salmon GnRH; sbGnRH, sea bream GnRH.
aOnly changed at 12 and 24 h in some groups.
Stimulatory effects on the HPG axis are underlined.