Uptake of (−) 3H-norepinephrine by storage vesicles prepared from whole rat brain: Properties of the uptake system and its inhibition by drugs

Uptake of Catecholamines by Storage Vesicles

“…The brain vesicles are also completely stereospecific for the /-form o f the catecholamines, a property also present in nor adrenergic vesicles from cardiac sympathetic neurons (5) but not adrenomedullary vesicles (11,66). Lastly, the Km for catecholamines of the uptake system of neuronal synaptic vesicles is several orders o f magnitude lower than that Add a-CIl j group increase no change Add methyl to N increase increase Add isopropyl to N increase decrease in adrenal preparations (27,39,46,53,60). Thus, while synaptic vesicles and adrenomedul lary vesicles share a number o f features pertain ing to uptake cofactors (62) and classes of inhibitory agents, the characteristics o f the catecholamine transport sites are different, with the neuronal preparations requiring a greater degree of resemblance to the natural catechol amine substrates.…”

“…Attempts at extensive puri fication o f an individual vesicle type, using density gradient ultracentrifugation in combina tion with membrane ultrafiltration, have been partially successful in identifying biogenic amine uptake, storage and energy requirement characteristics (65,67,68). Unfortunately, some degradation o f vesicle properties may occur during purification procedures, as evi denced by substantial loss of endogenous amine content (15) and by a 10-fold increase in the transport Km in purified vesicles compared to crude preparations (46,59,65,67). Crude vesicles prepared from brain regions o f the pig (39 41), display few differences among various biogenic amine vesicle types; subsequent re ports in rat whole brain and brain regions (46,59,61,62) indicate that dopaminergic and noradrenergic vesicles have identical uptake properties.…”

“…The current review, in addi tion to summarizing results obtained in adrenal preparations, indicates that the use o f the adre nal medulla as a model o f neurons has been only partially valid, and that differences do exist in the catecholamine uptake properties of synaptic vesicles from neurons compared to adrenomedullary vesicles. The adaptation o f the newer techniques to tissues o f small animals (46,56) has also enabled vesicle uptake tech niques to be utilized to examine physiological roles and pharmacological alterations of vesicle function in whole animals, and recent progress in this area will be reviewed.…”

“…In the past few years, new techniques for the isolation and characterization o f vesicles from neuronal tissues have been developed which permit studies to be performed similarly to those done originally in adrenomedullary vesi cles (39)(40)(41)46). The current review, in addi tion to summarizing results obtained in adrenal preparations, indicates that the use o f the adre nal medulla as a model o f neurons has been only partially valid, and that differences do exist in the catecholamine uptake properties of synaptic vesicles from neurons compared to adrenomedullary vesicles.…”

Maturation of Sympathetic Neurotransmission in the Rat Heart

“…A crude fraction containing synaptic vesicles was prepared from the heart homogenate by the method adapted from Seidler el al. [30] by Bareis and Slotkin [4], The homogenate was centrifuged at 1,000# for 15 min and (he pellet discarded. The supernatant was recentrifuged at 20,000 # for 30 min and this supernatant was sedimented at 100,000 g for 30 min in a Beckman Type 40 fixed angle rotor.…”