Available Online: http://www.ejpau.media.pl/volume3/issue1/fisheries/abs-01.html
EFFECTS OF PINEAL GLAND AND MELATONIN ON MATURATION GONADOTROPIN (GTH2) SECRETION FROM PERIFUSED PITUITARY GLANDS OF MATURE CARP DURING SPAWNING
Wlodzimierz Popek, Ewa Luszczek-Trojnar, Piotr Epler
The study, carried out during the spawning season, involved 30 mature carp females aged 5 years. The fish were divided into two experimental groups, those belonging to one of them being injected pimozide, a dopamine antagonist. The pituitaries and pineals were removed from all the females and perifused. Perifusion was carried out in pure medium alone, in the medium in the presence of the pineal gland, and in the medium enriched with dissolved melatonin. The perifusion proceeded in 2000 lux intensity light and in total darkness. Maturation gonadotropin (GtH2) concentration in the perifusion medium pumped through columns was determined with ELISA, an immunoenzymatic technique. The experimental treatments within each group showed no significant differences (p>0.01) with respect to the GtH2 concentrations in the perifusion medium. This result can be regarded as an evidence of a lack of any direct effect of the pineal gland and/or melatonin on GtH2 secretion from the carp pituitary during spawning.
Key words: pineal, melatonin, endocrine maturation control, pituitary, perifusion, carp..