sensitive indicator dyes (indo-1 or Fura-2), and the 
levels of [Ca^"*^]. measured in a fluorescent-acti- 
vated cell sorter and fluorimeter, respectively. Hista- 
mine increased [Ca^^]. in a dose-dependent man- 
ner, with a half-maximal concentration (EC,„) of 
—10 -10 M, which exhibited H^-receptor speci- 
ficity. Prostaglandin E and isoproterenol also in- 
' duced [Ca ]. mobilization in HL-60 cells, whereas 
the cell permeable form of cAMP and forskolin 
failed to increase [Ca^"*^].. Because H^-receptor- 
mediated [Ca^"*^]. mobilization was not inhibited by 
reducing the concentration of extracellular Ca^"*" 
nor by the addition of Ca^^ channel antagonists, 
LaCl-^ and nifedipine, [Ca^^]. mobilization is due 
to the release of Ca^^ from intracellular stores. 
Furthermore, both 10"^ M histamine and 10"*^ M 
f-Met-Leu-Phe (fMLP) increased the levels of inositol 
PUBLICATIONS 
triphosphate (1,4,5-IP3). However, histamine-in- 
duced mobilization of [Ca^^]. was inhibited by 
cholera toxin (CT) but not by pertussis toxin (PT), 
whereas the action of fMLP was inhibited by PT but 
not by CT. These data suggest that H^ receptors on 
HL-60 cells are coupled to two different CT-sensi- 
tive G proteins and activate adenylate cyclase and 
phospholipase C simultaneously. Currently Dr. 
Payan and his colleagues are examining the G pro- 
teins that are associated with the H^ receptor and 
whether they may be expressed at different times 
during cellular differentiation. 
Dr. Payan is also Associate Professor in Residence 
in the Departments of Medicine (Infectious Dis- 
ease) and Microbiology and Immunology at the 
University of California at San Francisco. 
Books and Chapters of Books 
Payan, D.G., and Shearn, M.A. 1989. Nonsteroidal anti-inflammatory agents; nonopiate analgesics; drugs 
used in gout. In Basic and Clinical Pharmacology (Katzung, B.G., Ed.). Norwalk, CT: Appleton & Lange, 
pp 431-450. 
Articles 
McGillis,J.P , Park, A. , Rubin-Fletter, P , Turck, C , Dallman, M., and Payan, D.R 1989. Stimulation of rat B-lym- 
phocyte proliferation by corticotrophin-releasing factor. J Neurosci Res 23:346-352. 
Mitsuhashi, M., and Payan, D.G. 1989. Receptor glycosylation regulates the affinity of histamine Hj receptors 
during smooth muscle cell differentiation. Mol Pharmacol 35:311-318. 
Mitsuhashi, M., and Payan, D.G. 1989. Solubilization and characterization of the pyrilamine-binding protein 
from cultured smooth muscle cells. Mol Pharmacol 35:751-759. 
Mitsuhashi, M., and Payan, D.G. 1989- Molecular and cellular analysis of histamine Hj receptors on cultured 
smooth muscle cells. / Cell Biochem 40:183-192. 
Payan, D.G. 1989. Neuropeptides and inflammation: the role of substance R Annu Rev Med 40:341-352. 
Payan, D.G. 1989. Substance P: a modulator of neuroendocrine-immune function. Hosp Pract 15:67-73, 76, 
78-80. 
Scicchitano, R., Dazin, R, Bienenstock, J., Payan, D.G., and Stanisz, A.M. 1988. The murine IgA-secreting plas- 
macytoma MOPC-315 expresses somatostatin receptors. J Immunol 141:937-941. 
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