The in vitro effect of levamisole on lymphocyte proliferation, polymorphonuclear leucocyte chemotaxis, basophil histamine release and platelet serotonin release in patients with atopic dermatitis

Expression of 5-HT1B receptors in human nasal mucosa

5-HT1B receptors were discovered in human nasal mucosa using immunocytochemistry. Strong immunoreaction was seen around small blood vessels mainly confined to the smooth muscle cell layer. In contrast, no immunoreaction for 5-HT1D was seen. The possibility of local release in connection with specific target receptors suggests a role for 5-HT in the regulation of vascular tone, glandular secretion and epithelial functions and that 5-HT1B receptor agonists may be of clinical importance.

Histamine contamination of pokeweed mitogen

The histamine content of commercial preparations of pokeweed mitogen was measured by amino acid analysis technique, automated fluorometry, and bioassay employing the guinea pig ileum. Ten samples from 5 companies were examined and found to contain between 0.026 micrograms and 167.5 micrograms of histamine per ml of solution. The protein content of 9 of these putative 5 mg samples measured by folin assay and by amino acid analysis varied from 0.56 to 4.4 mg. Their amino acid compositions were similar, except for notable variations in 3 of the 16 residues quantitated.