Relativein vitro effectiveness of estradiol-17β, androgens, corticosteroids, progesterone and other pregnene derivatives on germinal vesicle breakdown in oocytes of Indian major carps,Labeo rohita, Cirrhinus mrigala andCatla catla

Abstract

The relative effectiveness of estradiol-17β, androgens, corticosteroids, progesterone and other pregnene derivatives on germinal vesicle breakdown (GVBD) was investigatedin vitro using folliculated oocytes of three carps,Labeo rohita, Cirrhinus mrigala, andCatla catla. In all three species progesterone and 17α-hydroxyprogesterone could induce GVBD but relatively 17α,20β-dihydroxyprogesterone was consistently found to be the most potent maturation-inducing steroid. Both estradiol-17β and testosterone were ineffective in inducing GVBD. Androsterone and dehydroepiandrosterone were found to be effective inC. catla at all the concentrations used. Deoxycorticosterone (DOC), hydrocortisone (HC) and cortisone were effective inducer of GVBD inC. catla whereas inL. rohita andC. mrigala only cortisone was found to be effective. All 5β-reduced pregnenes were effective in inducing GVBD inL. rohita but inC. catla, only 5β-pregnane-17α-01-3,20-dione and 5β-pregnane-3α,17α,20β-triol and inC. mrigala, 5β-pregnane-3α-ol-20- one could induce oocyte maturation.

?Classical? and ?non-classical? reproductive steroids in fish

“…The progestogen 17,20fl-dihydroxy-4-pregnen-3-one (17,20tiP) was first identified in plasma of Pacific salmon (Oncorhynchus nerka, Salmonidae) by Idler et al (1960), and later studies showed it to be the most effective steroid in inducing GVBD in pike (Esox lucius, (Jalabert, 1976;Goetz and Bergman, 1978;Nagahama et al, 1983). More recent studies in four cyprinids Cyprinus carpio, Labeo rohita, Cirrhinus mrigala and Catla catla (Epler, 1981;Inbaraj and Haider, 1988;Haider and Inbaraj, 1989), the siluriform Mystus vitattus (Bagridae) (Upadhyaya and Haider, 1986), the Japanese whiting (Sillago japonica, Sillaginidae, Perciformes) (Matsuyama et al, 1990b) and the marine flatfish Limanda limanda (Pleuronectidae) and Pleuronectes platessa (Pleuronectidae) (Canario and Scott, 1990a) have confirmed its efficacity in other species. In some of these cases, however, other steroids such as 17,20fl,21-trihydroxy-4-pregnen-3-one (17,20fl,21P), 5-pregnene-3fl, 17,20fl-triol (17,20fl-P5), and 11-deoxycortisol (17,21-dihydroxy-4-pregnene-3,20-dione; 17,21P) have comparable activity to that of 17,20tiP, while a number of other steroids, including 5fl-reduced compounds, have significant activity.…”

The induction of oocyte maturation and ovulation in the European eel (Anguilla anguilla): in vitro and in vivo comparison of progesterone with 17α,20β-dihydroxy-4-pregnen-3-one

“…DHP treatment can have important disadvantages as females have to ovulate within 18 h as hatching rates and fertility decrease after this period ( Ohta et al, 1996 ; Kagawa, 2003 ; Palstra and van den Thillart, 2009 ). P, a precursor of DHP in the steroidogenic pathway, has been found to induce oocyte maturation and ovulation in fish species belonging to the elopomorphs ( Adachi et al, 2003 ), silurids ( Upadhyaya and Haider, 1986 ), salmonids ( Jalabert, 1976 ), cyprinids ( Jalabert, 1976 ; Haider and Inbaraj, 1989 ) and esociformes ( Jalabert, 1976 ). Based on the two-cell type model developed in salmonids ( Nagahama, 1997 ), it is commonly believed that P, which is formed in the theca cells from pregnenolone, is converted into 17α-hydroxyprogesterone that crosses the basal lamina and is then converted into DHP in the granulosa cells.…”

“…We can therefore conclude that DHP and P work equally well as MIH, supporting the alternative hypothesis that P directly induces the last steps of oocyte development. DHP was found to be the most important MIH and P was considered a precursor in its biosynthesis in many fish species ( Jalabert, 1976 ; Upadhyaya and Haider, 1986 ; Nagahama, 1987 ; Haider and Inbaraj, 1989 ; Adachi et al, 2003 ). By acting upstream in the steroidogenic pathway, P would stimulate the production of endogenous DHP by the folliculated oocytes.…”

Human follicular fluid shows diverse metabolic profiles at different follicle developmental stages

“…In addition, DOC can stimulate Gn release, promote the development of follicles, and induce LH surges to ovulate [28]. DOC was discovered to effectively induce GVBD at all concentrations, and regulates the final oocyte maturational stages in fish [29,30]. These two metabolites are associated with the sensitivity of the body to Gn and could be used as prediction indices for Gn.…”