Marc Jupin1,2, Frits H A van Heijster1, Arend Heerschap3. 1. Department of Medical Imaging, Radboud University Medical Center, Geert Grooteplein zuid 10, 6525 GA, Nijmegen, The Netherlands. 2. Biophysical Chemistry, Institute for Materials and Molecules, Radboud University, Heyendaalseweg 135, 6524AJ, Nijmegen, The Netherlands. 3. Department of Medical Imaging, Radboud University Medical Center, Geert Grooteplein zuid 10, 6525 GA, Nijmegen, The Netherlands. arend.heerschap@radboudumc.nl.
Abstract
INTRODUCTION: Molecular interactions in prostatic fluid are of biological interest and may affect MRI and MRS of the prostate. We investigated the existence of interactions between the major components of this fluid: spermine, citrate and myoinositol, metal ions, including zinc, and proteins. MATERIALS AND METHODS: Solutions of 90 mM citrate, 18 mM spermine and 6 mM myo-inositol, mimicking expressed prostatic fluid, were investigated by 1H NMR using changes in T2 relaxation and chemical shift as markers for interactions. RESULTS AND DISCUSSION: Adding to this metabolite mixture the ions Na+ , K+, Ca++, Mg++ and Zn++, decreased the T2 relaxation times of citrate and spermine protons by factors of 3 and 2, respectively, with Zn++ causing the largest effect, indicating ion-metabolite interactions. The T2 of 18 mM spermine dropped by a factor of 2 upon addition with 90 mM citrate, but no effect on T2 was seen with myo-inositol pointing to a specific citrate-spermine interaction. Moreover, the T2 of citrate in the presence of spermine decreased by adding metal ions and increasing amounts of Zn++, indicating complexation of citrate and spermine with metal ions, particularly with Zn. The addition of bovine serum albumin (BSA), as an index protein, substantially further decreased the T2 of spermine and citrate implying the formation of a transient spermine-metal ion-citrate-BSA complex. Finally, we found that the T2 of citrate in extracellular fluid of prostate cancer cells, as a mimic of fluid in cancerous prostates, decreased by adding fetal calf serum, indicating protein binding.
INTRODUCTION: Molecular interactions in prostatic fluid are of biological interest and may affect MRI and MRS of the prostate. We investigated the existence of interactions between the major components of this fluid: spermine, citrate and myoinositol, metal ions, including zinc, and proteins. MATERIALS AND METHODS: Solutions of 90 mM citrate, 18 mM spermine and 6 mM myo-inositol, mimicking expressed prostatic fluid, were investigated by 1H NMR using changes in T2 relaxation and chemical shift as markers for interactions. RESULTS AND DISCUSSION: Adding to this metabolite mixture the ions Na+ , K+, Ca++, Mg++ and Zn++, decreased the T2 relaxation times of citrate and spermine protons by factors of 3 and 2, respectively, with Zn++ causing the largest effect, indicating ion-metabolite interactions. The T2 of 18 mM spermine dropped by a factor of 2 upon addition with 90 mM citrate, but no effect on T2 was seen with myo-inositol pointing to a specific citrate-spermine interaction. Moreover, the T2 of citrate in the presence of spermine decreased by adding metal ions and increasing amounts of Zn++, indicating complexation of citrate and spermine with metal ions, particularly with Zn. The addition of bovine serum albumin (BSA), as an index protein, substantially further decreased the T2 of spermine and citrate implying the formation of a transient spermine-metal ion-citrate-BSA complex. Finally, we found that the T2 of citrate in extracellular fluid of prostate cancer cells, as a mimic of fluid in cancerous prostates, decreased by adding fetal calf serum, indicating protein binding.
Authors: Eric E Kline; Eric G Treat; Tiffany A Averna; Michael S Davis; Anthony Y Smith; Laurel O Sillerud Journal: J Urol Date: 2006-11 Impact factor: 7.450
Authors: Thiele Kobus; Pieter C Vos; Thomas Hambrock; Maarten De Rooij; Christina A Hulsbergen-Van de Kaa; Jelle O Barentsz; Arend Heerschap; Tom W J Scheenen Journal: Radiology Date: 2012-07-27 Impact factor: 11.105
Authors: Natalie J Serkova; Eduard J Gamito; Richard H Jones; Colin O'Donnell; Jaimi L Brown; Spencer Green; Holly Sullivan; Tammy Hedlund; E David Crawford Journal: Prostate Date: 2008-05-01 Impact factor: 4.104