Accumulation of [3H]ATP in small dense core vesicles of superfused vasa deferentia

NORADRENALINE is stored in sympathetic nerves in at least (see TRANZER, 1973) two populations of vesicles (see GEFFEN & LIVETT, 1971 ; SMITH, 1972). Morphologists have characterized these populations as consisting of small and large dense core vesicles (see GEFFEN & LIVETT, 1971). Biochemists using density gradient centrifugation have also separated vesicle populations into two groups: light and heavy density fractions (ROTH er al., 1968; CHUBB et al., 1970; BISBY & FILLENZ, 1971 ; NELSON & MOLINOFF, 1976). Evidence has been presented (BISBY & FILLENZ, 1971) that the light vesicles correspond to the small dense core vesicles and that the heavy vesicles are the biochemical correlate of the large dense core ones. The biochemical properties of the large dense core vesicles have been studied in some detail (LAGERCRANTZ, 1976) and their composition appears to closely resemble that of the well characterized (see WINKLER, 1976) chromaffin granules. Small dense core vesicles, like the large ones, contain dopamine fi-hydroxylase (BISBY et al., 1973; DE POTTER & CHUBB, 1977) and cytochrome b-561 (FRIED, 1978). A partial purification of these vesicles from rat vas deferens has recently been reported (FRIED et al., 1978). In this study castrated rats were used since the vasa deferentia from these animals contained an increased concentration of sympathetic nerves due to muscle atrophy. We have recently demonstrated that the catecholaminestoring organelles of the adrenal medulla, i.e. the chromaffin granules, take up ATP and other nucleotides by a carrier-mediated process (KOSTRON er d., 1977; WINKLER, 1977). This uptake is driven by a proton gradient (ABERER rt a/., 1978) generated by the Mgz+ activated ATPase which is also responsible for catecholamine transport (see NJUS & RADDA, 1978). In this paper we present evidence that the small dense core vesicles found in the sympathetic nerves of vasa deferentia also can accumulate C3H]ATP when the tissue is pulse labelled' with C3H]adenosine.