Involvement of steroid hormones in the preovulatory gonadotropin surge in female goldfish

Kobayashi, Makito; Aida, Katsumi; Hanyu, Isao

doi:10.1007/bf00004700

Cited by 32 publications

(8 citation statements)

References 26 publications

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“…The nano-form of LHRH could penetrate deep into tissues through fine capillaries, cross the epithelial lining, and is taken up efficiently by the cells [37]. Elevated testosterone and estradiol levels during vitellogenic growth and ovulation found in this study are consistent with published reports in many species [38]–[40]. Plasma 17α, 20β- OHP levels in nano LHRH-injected fish followed the same trend as estradiol and testosterone.…”

Section: Discussionsupporting

confidence: 90%

Chitosan-Nanoconjugated Hormone Nanoparticles for Sustained Surge of Gonadotropins and Enhanced Reproductive Output in Female Fish

et al. 2013

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A controlled release delivery system helps to overcome the problem of short life of the leutinizing hormone releasing hormone (LHRH) in blood and avoids use of multiple injections to enhance reproductive efficacy. Chitosan- and chitosan-gold nanoconjugates of salmon LHRH of desired size, dispersity and zeta potential were synthesized and evaluated at half the dose rate against full dose of bare LHRH for their reproductive efficacy in the female fish, Cyprinus carpio. Whereas injections of both the nanoconjugates induced controlled and sustained surge of the hormones with peak (P<0.01) at 24 hrs, surge due to bare LHRH reached its peak at 7 hrs and either remained at plateau or sharply declined thereafter. While the percentage of relative total eggs produced by fish were 130 and 67 per cent higher, that of fertilised eggs were 171 and 88 per cent higher on chitosan- and chitosan-gold nanoconjugates than bare LHRH. Chitosan nanoconjugates had a 13 per cent higher and chitosan gold preparation had a 9 per cent higher fertilization rate than bare LHRH. Histology of the ovaries also attested the pronounced effect of nanoparticles on reproductive output. This is the first report on use of chitosan-conjugated nanodelivery of gonadotropic hormone in fish.

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Section: Discussionsupporting

confidence: 90%

Chitosan-Nanoconjugated Hormone Nanoparticles for Sustained Surge of Gonadotropins and Enhanced Reproductive Output in Female Fish

et al. 2013

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“…In goldfish, Khoo (1975) observed that the steroidogenic activity begins only after complete removal of atretic oocytes, and in the postovulatory follicles steroidogenesis begins immediately after ovulation. In this species, in vitro experiments showed that the postvitellogenic follicles produced T but not E2 (Kobayashi et al, 1989).…”

Section: Discussionmentioning

confidence: 80%

Comparative study of reproductive biology in single and multiple‐spawner cyprinid fish. II. Sex steroid and plasma protein phosphorus concentrations

Rinchard

Kestemont

Heine

1997

Journal of Fish Biology

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The dynamics and regulation of oogenesis in single and multiple-spawner cyprinid fish showing group-synchronous oocyte development, was investigated in three species from the River Meuse (Belgium): the roach Rutilus rutilus as a single spawner, and the bleak Alburnus alburnus and the white bream Blicca bjoerkna as multiple spawners. This paper compares the seasonal profiles of sex steroids (oestradiol-17 , testosterone and 17,20 -dihydroxy-4-pregnen-3-one) and plasma alkali-labile protein phosphorus. Different patterns of plasma oestradiol-17 (E2) and plasma protein phosphorus (PPP) have been observed not only between the single and the multiple spawner fish, but also among the two multiple spawners. In roach, two increases of E2 levels were observed. The first occurred in September after a short gonadal quiescent period, and coincided with the increase of the PPP at the onset of exogenous vitellogenesis. The second took place in spring before the spawning season. The low PPP recorded during that period probably reflected its rapid incorporation by the oocytes. In both multiple spawners, highest values of PPP were recorded just before the spawning season. In white bream, the PPP declined progressively once the differentiation of exogenous vitellogenic oocytes was completed before the onset of the spawning season. In bleak, PPP levels remained high throughout the spawning season and corresponded to a sustained oocyte recruitment during the whole of this period. Regardless of the pattern of oocyte growth recruitment, the E2 concentrations were high in both multiple spawner species during the breeding season. In the three species, testosterone levels remained low regardless of the maturation stage (ranging from 0·6 to 13·4 ng ml 1 ). Except for relatively high concentrations of 17,20 P in roach during final maturation and postspawning stages (20 and 28 ng ml 1 , respectively), low levels of this steroid were measured in these cyprinids, and especially in the multiple spawner fish. The role of this progestogen as the maturation inducing steroid is discussed. 1997 The Fisheries Society of the British Isles

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“…Each diol-17b in mammals (positive feedback; stimulation of occurrence of preovulatory surge in LH or GTH II). 14,15 2. Sex steroids increase basal plasma GTH II levels in sexually immature rainbow trout 16 and male Atlantic salmon Salmo salar parr.…”

Section: Experiments 1 and 2: Effects Of Ovariectomy And Steroid Replmentioning

confidence: 99%

Effects of sex steroids on the mRNA levels of gonadotropin subunits in juvenile and ovariectomized goldfish Carassius auratus

et al. 2000

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SUMMARY: In order to elucidate the regulation of gonadotropin (GTH) gene expression by gonadal sex steroids, the effects of ovariectomy and sex steroid administration on pituitary mRNA levels of GTH subunits were examined in goldfish. Ovariectomy caused a marked increase in GTH Iβ mRNA levels, and steroid hormone replacement (testosterone, T; estradiol‐17β, E2; and 11‐ketotestosterone, KT) suppressed the elevated levels in sexually early recrudescent and mature females. Pituitary mRNA levels of α and GTH IIβ were not affected by ovariectomy and steroid hormone treatment. When sex steroids (T, E2, and KT) were administered to sexually immature juvenile fish, GTH Iβ mRNA levels were suppressed as observed in adult fish. However, GTH IIβ mRNA levels were observed to increase by sex steroids (T and E2 but not KT) unlike that observed with adult fish. These results indicate that sex steroids exert an inhibitory effect on GTH Iβ mRNA levels from the time goldfish are immature to the time they are mature. However, sex steroids (T and E2) have a stimulatory effect on GTH IIβ mRNA levels in juvenile goldfish and the effect becomes less pronounced when they become adult.

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Involvement of steroid hormones in the preovulatory gonadotropin surge in female goldfish

Cited by 32 publications

References 26 publications

Chitosan-Nanoconjugated Hormone Nanoparticles for Sustained Surge of Gonadotropins and Enhanced Reproductive Output in Female Fish

Chitosan-Nanoconjugated Hormone Nanoparticles for Sustained Surge of Gonadotropins and Enhanced Reproductive Output in Female Fish

Comparative study of reproductive biology in single and multiple‐spawner cyprinid fish. II. Sex steroid and plasma protein phosphorus concentrations

Effects of sex steroids on the mRNA levels of gonadotropin subunits in juvenile and ovariectomized goldfish Carassius auratus

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