A comparison of tritiated vitellogenins prepared by in vivo and in vitro techniques for studies of ovarian uptake in fish

✍ Scribed by Nagler, James J. ;Idler, David R. ;So, Ying P.

• Publisher: John Wiley and Sons
• Year: 1992
• Tongue: English
• Weight: 669 KB
• Volume: 264
• Category: Article
• ISSN: 0022-104X
• DOI: 10.1002/jez.1402640116

✦ Synopsis

Abstract

This study provides a comparison between serum vitellogenins (VGs), which have been radiolabelled with tritium (^3^H) using two different labelling methods, for ovarian uptake studies in fish. Purified VGs from winter flounder (Pseudopleuronectes americanus) and rainbow trout (Oncorhynchus mykiss) were radiolabelled in vitro following reaction with [^3^H]succinimidyl propionate which resulted in stable high specific activity [^3^H]propionyl‐VGs. Radiolabelled VGs were also prepared in vivo by injecting female winter flounder and rainbow trout with estradiol‐17β and [^3^H] amino acids intraperitoneally, and subsequently harvesting the serum and isolating the [^3^H]VGs. In winter flounder the ovarian uptake after a single intravenous injection of either [^3^H]propionyl‐VG or [^3^H]VG into female fish was determined after two weeks. Winter flounde VGs, radiolabelled either in vitro or in vivo, were similarly taken up by the ovary during early and mid phases of the annual vitellogenic cycle. It was demonstrated that both [^3^H]propionyl‐VG and [^3^H]VG were processed into a 280,000 relative molecular mass protein (i.e. lipovitellin). The small size of the vitellogenic winter flounder ovarian follicle precludes their use for in vitro culture, therefore an experiment was performed using rainbow trout ovarian follicles. Rainbow trout [^3^H]propionyl‐VG and [^3^H]VG were similarly incorporated by defolliculated ovarian follicles after 2, 6, and 12 hours of in vitro culture. © 1992 Wiley‐Liss, Inc.