The G proteins G 5 and G~1appear to be capable of binding to tubulin specifically, and it has been suggested that such binding results in G protein activation via direct transfer of GTP. This study was undertaken to demonstrate that consequences of G protein activation by tubulin, i.e., stimulation or inhibition of adenylyl cyclase, were dependent on the G proteins expressed as well as unique aspects of the membrane or cytoskeleton in a given cell type. Membranes from rat 06 glioma cells, which express G5,, but not G~,,1, responded to the addition of tubulin with a stable activation of adenylyl cyclase. Conversely, membranes from rat cerebral cortex, which contain both G5 and G1, responded to exogenous tubulin with a stable inhibition of adenylyl cyclase. Unlike 06 membranes, cerebral cortex membranes are richly endowed with tubulin, and antitubulin antibodies immuno-precipi~atedcomplexes of tubulin and G,1 or G5 from detergent extracts of these membranes. Nearly 90% of the G5,, from Triton X-114 extracts coimmunoprecipitated with tubu~n,suggesting that these proteins exist as a complex in the synaptic membrane. Such complexes may provide the framework for a G protein-cytoskeleton link that participates in the modulation of cellular signal transduction.

Post amputation pain can be debilitating for patients and families. Chronic pain is a common phenomenon after lower extremity amputation, occurring in up to 80% of this population. The purpose of this pilot study was to correlate post amputation pain scores to opioid analgesic consumption and Beck Anxiety Inventory (BAI) scores. Twenty-three patients with lower extremity amputation at an 827-bed acute care inner-city hospital were surveyed pre-operatively and post-operatively to determine if there was a significant correlation between anxiety and pain. A numeric scale was utilized by patients to rate their pain level, while the BAI was utilized to measure their anxiety levels.A significant correlation was found between the pre-operative BAI levels and the BAI levels identified at time of discharge. Patients were found to have a higher than normal level of anxiety pre-operatively. No significant correlations were found between anxiety and pain.