The influence of cadmium on Prussian carp oocyte maturation, development of eggs and hatching

Self Cite

Fadrozole -a non-steroidal aromatase inhibitor was applied to common carp and goldfish to examine its ability to potentiate the stimulatory action of GnRH analogues on LH secretion in vivo. The goal of the project was to find a substitute for antidopaminergic drugs used with GnRH analogues in fisheries practice to stimulate ovulation in fish bred in captivity. The first trials on goldfish showed a moderate ability of fadrozole to potentiate salmon GnRH analogue stimulation, weaker than that obtained with pimozide (dopamine antagonist). No ovulation in fadrozole-treated fish was observed. Several experiments performed in two consecutive reproductive seasons (different treatment regimes and doses of fadrozole) neither improved nor confirmed the results obtained in the first year. The analysis of 17β-estradiol levels in the blood plasma and in hypothalami showed no changes in the concentration of this steroid in fadrozole-treated fish in comparison with the controls. This shows that fadrozole is not able to replace the antidopaminergic drugs used in fisheries practice and cannot be considered as a potential ovulation inducer in cyprinids.

Section: Hormone Level Analysismentioning

confidence: 99%

LH secretion and 17ββ-estradiol concentration in the blood plasma and hypothalamus of goldfish (Carassius auratus gibelio B.) and common carp (Cyprinus carpio L.) treated with fadrozole (aromatase inhibitor) and GnRH analogues

Mikołajczyk¹,

Sokolowska-Mikolajczyk²,

Chyb³

et al. 2007

Self Cite

“…The mechanisms controlling meiotic competence acquisition and meiotic maturation are not fully understood (Wierzchos, 2006;Wang et al, 2007;Szczerbik et al, 2008). The role of nitric oxide (NO), which is a cellular messenger arising from L-arginine oxidation by the NO-synthase (NOS) enzyme, is not clear yet.…”

mentioning

confidence: 99%

Expression and localization of nitric oxide synthase isoforms during porcine oocyte growth and acquisition of meiotic competence

Eva¹,

Sedmı́ková²,

Petr³

et al. 2009

The intensive development of biotechnologies such as in vitro embryo production and cloning by nuclear transfer requires a great number of oocytes with fully-developed meiotic competence.During in vitro culture these oocytes are able to reach the stage of second meiotic metaphase and complete their meiotic maturation. However, the number of these oocytes in the ovary is limited. ABSTRACT: Reproduction biotechnologies depend on the use of fully meiotically competent oocytes. Growing oocytes without full meiotic competence are an interesting potential source due to their quantity, but the mechanisms regulating the processes of acquisition of meiotic competence have not been clarified to date. Nitric oxide synthase (NOS) and its product, nitric oxide (NO), may possibly play a role. Understanding the precise NO regulatory mechanism is therefore important for the development of in vitro growth methods. The objective of this work was to detect changes in the expression of NOS isoforms and their mRNA expression and changes in the intracellular localization of separate NOS isoforms during the growth period of the porcine oocyte, and also to determine whether these changes are related to the process of meiotic competence acquisition. mRNA for all NOS isoforms was already detected in oocytes at the beginning of their growth and was present in them until they completed their growth period. mRNA for iNOS and eNOS was also observed in granulosa and cumulus cells from these oocytes. But nNOS mRNA was not demonstrated in these types of cells. Pig oocytes and their surrounding cells contained all NOS proteins. Their amounts increased and localization changed with the acquisition of meiotic competence. nNOS was localized mainly in the cortex in meiotically incompetent oocytes, while meiotically competent oocytes contained nNOS in the nucleus as well. iNOS protein was distributed in the cytoplasm and nucleus in all oocytes, and meiotically incompetent oocytes contained iNOS in the nucleolus as well. eNOS protein was distributed in oocytes in the form of fine granules with a strong fluorescence signal. Protein was concentrated in the nuclear area in meiotically incompetent oocytes and also in the periphery in oocytes with partially and fully-developed meiotic competence. All these findings indicate that NOS isoforms may significantly influence the acquisition of meiotic competence in porcine oocytes.

“…The LH analysis was performed according to the method of Kah et al (1989). The plasma samples for 17,20b-P were extracted with dichloromethane prior to the measurement of this steroid and subjected to 17,20b-P determination according to the method described by Szczerbik et al (2008).…”

Section: Methodsmentioning

confidence: 99%

Effects of Aroclor 1254 on LH and 17,20β-P secretion in female Prussian carp (Carassius gibelio Bloch) in the spawning season

Socha¹,

Sokolowska-Mikolajczyk²,

Szczerbik³

et al. 2013

Self Cite

ABSTRACT:The effects of Aroclor 1254 on the secretion of luteinizing hormone (LH) and 17,20β-dihydroxy-4-pregnen-3-one (17,20β-P) in female Prussian carp (Carassius gibelio Bloch) at the time of their natural spawning were determined. Aroclor 1254 at doses of 0.01, 0.1, and 1 mg/kg body weight was dissolved in 500 ml of oil and was administered three times intraperitoneally or rectally to female Prussian carp every 24 h for three days. Blood samples were collected after 3 days of Aroclor 1254 administration to determine the LH and 17,20β-P concentrations using ELISA. At 6, 12, and 24 h after injection of gonadotropin-releasing hormone analogue (GnRH-A) blood samples were collected for stimulated LH secretion determination. Aroclor 1254 administered intraperitoneally (0.1 and 1 mg/kg) and rectally (0.01 and 1 mg/kg) significantly increased spontaneous LH secretion. In the case of GnRH-A-stimulated LH release, Aroclor 1254 (administered intraperitoneally only) at concentrations of 0.1 and 1 mg/kg significantly decreased gonadotropin release. The intraperitoneal injections of the lowest tested concentration of Aroclor 1254 also significantly decreased 17,20β-P secretion. The results show that Aroclor 1254 can affect the reproductive system of Prussian carp by changing the secretion of two very important hormones, LH and 17,20β-P, at the time of natural spawning.