Dopamine control of LH release in the tench (Tinca tinca)

Dose-dependent effect of a single GnRHa injection on the spawning of meagre (Argyrosomus regius) broodstock reared in captivity

“…The observation in the present study that meagre have a narrow range of optimal dose of a single injection to induced spawning could be interpreted to be contradictory to studies that found a broad range of GnRHa doses successfully induced spawning in other species and that have concluded that for economic reasons lower doses should be used (Yang & Chen, 2004;Podhorec et al, 2012). However, the present study can also be interpreted to have found a broad range of doses (10-30) that have successfully induced spawning.…”

“…Optimal GnRHa doses have also been found in similar studies on sea bass (Lates calcarifer) (Garcia, 1989), gilthead seabream (Sparus aurata) (Barbaro et al, 1997) and spotted rose snapper (Lutjanus guttatus) (Ibarra & Duncan, 2007). It has been demonstrated that GnRHa stimulates spawning in fish with arrested maturation by releasing LH from the pituitary, which in turn stimulates oocyte maturation and the fish to spawn (Zohar et al, 1995;Mañanos et al, 2002;Podhorec et al, 2012). Increasing doses (1-20 µg kg -1 ) of mammalian gonadotrophin-releasing hormone agonists, mGnRHa ([DAla 6 , Pro 9 , NEthylamide]-mGnRH) were positively correlated to levels of circulating LH and ovulation rate in tench (Tinca tinca) (Podhorec et al, 2011) and high GnRHa doses have been described to accelerate oocyte development (Mylonas et al, 1992;Barbaro et al, 1997;Mugnier et al, 2000;Duncan et al, 2003).…”

Retracted: Effective Dose of Salmon GnRHa for Induction of Ovulation in Channel Catfish

“…In general, higher doses of ovulating hormone are required to induce spawning in Channel Catfish to produce hybrid catfish in hatcheries (Chatakondi et al 2011). Higher doses of hormone often result in needless overdosing (Podhorec et al 2012), higher hormone costs, and reduced egg quality (Mylonas et al 1992;Taranger et al 1992). In the present study, the minimum effective dose of sGnRHa to induce ovulation was determined to be 15 µg/kg BW and resulted in higher relative fecundity (8,322 eggs/kg BW) and number of fry (2,533 fry/kg BW).…”

Application of dopaminergic antagonist: Metoclopramide, in reproduction of crucian carp Carassius carassius (L.) under controlled conditions

“…Interestingly, the administration of MET alone in the same dose (20 mg/kg) did not induce ovulations in tench Tinca tinca (L.), whereas application of 10 g/kg of GnRHa (without MET) resulted in almost 70% ovulation success. The greatest ovulatory response (90%) of tench was noted after the application of a combined preparation of GnRHa (10 g/kg) and DA-MET (20 g/kg; Podhorec et al, 2012).…”