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Just a Matter of Time?

Scientists at INFLAMOCORP Inc., have discovered an unique granulated cell that releases a novel peptide when stimulated by inflammatory mediators such as histamine. The cells can be grown in culture and the secretion of the peptide monitored by an extremely sensitive and reliable assay system.

They have recruited a student Matt O. from the Bio-Pharm Coop programme for a summer work term. Matt has been asked to test the effects of bradykinin (BK) a well studied inflammatory peptide.

Matt does the following experiment:

He obtains a supply of the cells and sets them up in an incubation system. The incubation system is a set of wells containing an equivalent number of cells. He tests the effects of exogenously added bradykinin and as a positive control, histamine. This can be readily done by incubating the cells for a fifteen minute period with increasing concentrations added to the incubation medium. Only one concentration is added to a particular well and all experiments are done in triplicate. Samples are removed and promptly assayed in an on-line automated system. This enables Matt to get results very quickly. The first experiment done in the morning gives the results shown (Fig 1). Matt is pleased that he has been able to reproduce the effects of histamine but is disappointed at the BK data.

However, there are enough cells left so Matt decides to try another experiment after lunch. That takes longer than usual, since he runs across other Bio-Pharmers and finds it difficult to tear himself away from the gossip. When he gets back to the lab, 3 hours have elapsed. Nevertheless, he decides to repeat the experiment and gets the results shown in the Figure 2.

Matt is wildly excited and cannot get to sleep that night. The next day he rushes into the lab and repeats the experiment. To his horror, he finds that the cells respond predictably to histamine, but once again there is NO effect of bradykinin.

  
Figure 1

Shows the responses of isolated cells to increasing concentrations of histamine and BK. Cells were incubated in physiological salt solutions and the peptide released quantified by a novel assay system

cacklin.jpg (41774 bytes)

Figure 2
Shows the responses to the same agonists.

cacklin2.JPG (41721 bytes)


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