Nuclear magnetic resonance studies of the adrenal gland and some other organs.

Abstract

KNOWLEDGE of the state of many chemicals in cell compartments is based on inference from analytical methods carried out after partial or complete disruption of the cell. This situation arises as most of the cell contents have similar spectroscopic properties and cannot be studied inside a cell. We have shown that the contents of intact vesicles of the adrenal medulla (chromaffin granules) can be studied by nuclear magnetic resonance (NMR) in separated vesicles1. (We have subsequently shown (unpublished observations) that the spectra are quantitative and that all the adrenaline present in the granules is observed by NMR spectroscopy.) From this study1 we could establish an outline structure of the internal solution of these granules. The question then arises as to whether precisely this structure exists in the organelle within the cell or whether isolation of organelles such as these modified their properties. We report here that improved NMR methods can provide detailed information about the environment and mobility of small molecules and some proteins even within intact organs. As little as 10mg (dry weight) of tissue is required. No other technique can provide such information at present. Furthermore, the NMR data can be used to describe structural features of the organisation of the cell.