Disc-electrophoretic identification of prolactin in the cichlid teleosts Tilapia and Cichlasoma and densitometric measurement of its concentration in Tilapia pituitaries during salinity transfer experiments

Publisher Website
Google Scholar
Abstract
The prolactin band was identified after disc electrophoresis of pituitaries from Tilapia mossambica and Cichlasoma labiatum. Electrophoresis coupled with a densitometric procedure was validated as a means of measuring the prolactin content of Tilapia pituitaries during salinity transfer experiments. Transfer of T. mossambica from seawater or 33% sea water to fresh water was followed by a sharp decline in both plasma sodium and pituitary prolactin levels. One week after transfer, there was a recovery of sodium levels to normal, although pituitary prolactin concentrations had not yet reached the level found in fully acclimated freshwater fish. Pituitary prolactin levels in T. grahami were reduced by more than 50% on the day after transfer from Lake Magadi (alkaline–saline) water to fresh water. No such depletion of pituitary prolactin followed a transfer from 100% seawater or from fresh water to 33% seawater, indicating that this response is specifically linked to the secretion of prolactin for osmoregulation in fresh water. The molecular weight of Tilapia prolactin was estimated at 17 000 by means of electrophoresis in sodium dodecyl sulfate.

This publication has 0 references indexed in Scilit: