Differential chemotactic activities of sensory neuropeptides for human peripheral blood mononuclear cells

We studied the chemotactic effects of calcitonin gene-related peptide, vasoactive intestinal peptide, substance P (SP), and secretoneurin on PBMC and PBL using micropore filter assays. All four peptides induced migration of PBMC, whereas only calcitonin gene-related peptide, vasoactive intestinal peptide, and SP were chemotactic for PBL. Secretoneurin, known to induce monocyte chemotaxis, was unable to affect lymphocyte migration. Effects of SP on PBL were characterized by checkerboard analyses and represented true chemotaxis. Both T and B cells responded chemotactically to SP, the functional activity of SP residing in its C-terminal amino acid sequence. Involvement of neurokinin (NK) receptors was supported by inhibition of SP-induced migration of PBL with an NK1 receptor antagonist and induction of migration with [Sar9, Met(O2)11]SP and [PyrGlu6, Pro9]SP(6-11), two specific agonists for NK1 receptors, but not with [beta-Ala8]NK A(4-10), an agonist for NK2 receptors. PBL chemotaxis to SP was abolished by inhibition of tyrosin kinase but not by that of protein kinase C. Preincubation of PBL with pertussis or cholera toxin inhibited SP chemotaxis, indicating that in PBL, NK receptors for chemotaxis probably are coupled with G protein and involve a tyrosin kinase signaling pathway. We conclude that, together with calcitonin gene-related peptide and vasoactive intestinal peptide, SP is a lymphocyte chemoattractant, whereas secretoneurin, which is coreleased from sensory nerve endings, is not.

Differential chemotactic activities of sensory neuropeptides for human peripheral blood mononuclear cells

We studied the chemotactic effects of calcitonin gene-related peptide, vasoactive intestinal peptide, substance P (SP), and secretoneurin on PBMC and PBL using micropore filter assays. All four peptides induced migration of PBMC, whereas only calcitonin gene-related peptide, vasoactive intestinal peptide, and SP were chemotactic for PBL. Secretoneurin, known to induce monocyte chemotaxis, was unable to affect lymphocyte migration. Effects of SP on PBL were characterized by checkerboard analyses and represented true chemotaxis. Both T and B cells responded chemotactically to SP, the functional activity of SP residing in its C-terminal amino acid sequence. Involvement of neurokinin (NK) receptors was supported by inhibition of SP-induced migration of PBL with an NK1 receptor antagonist and induction of migration with [Sar9, Met(O2)11]SP and [PyrGlu6, Pro9]SP(6-11), two specific agonists for NK1 receptors, but not with [beta-Ala8]NK A(4-10), an agonist for NK2 receptors. PBL chemotaxis to SP was abolished by inhibition of tyrosin kinase but not by that of protein kinase C. Preincubation of PBL with pertussis or cholera toxin inhibited SP chemotaxis, indicating that in PBL, NK receptors for chemotaxis probably are coupled with G protein and involve a tyrosin kinase signaling pathway. We conclude that, together with calcitonin gene-related peptide and vasoactive intestinal peptide, SP is a lymphocyte chemoattractant, whereas secretoneurin, which is coreleased from sensory nerve endings, is not.

[Kallikrein (urine) in pregnancy-induced hypertension]

Total, active and inactive renal kallikrein were compared between 25 patients with hypertensive disorders of pregnancy and 25 healthy pregnant women of corresponding gestational age. Values of all three fractions were twice as high in healthy women than in hypertensive patients and differed with statistical significance. A longitudinal examination of renal kallikrein during pregnancy showed a physiological decrease of values from the 16th-20th week until term. Asymptomatic women, who developed hypertension later on, showed decreased renal kallikrein values.

Human chorionic gonadotrophin: a chemoattractant for human blood monocytes, neutrophils and lymphocytes

Treatment of rats with human chorionic gonadotrophin (hCG) induced in the testes an inflammation-like reaction characterized by migration of leukocytes into the interstitial space. In order to find out whether hCG acts in a direct manner in this process, we tested peripheral human blood leukocyte attraction by hCG in vitro. Chemotaxis through cellulose nitrate to gradients of test substances was measured using a 48-well microchemotaxis chamber. Human CG was found to be a potent attractor of neutrophils, monocytes and lymphocytes in vitro in the picomolar concentration range. Checkerboard analyses revealed that the type of migration depends on positive concentration gradients of hCG. The chemoattractant nature of hCG is consistent with its having a role to play in regulation of tissue accumulation of these cells within the reproductive tract.

Stimulation of the chemotactic migration of human fibroblasts by substance P

Neuropeptides exert a variety of modulatory effects on inflammatory cellular responses. In order to investigate further activities of these cytokines on mechanisms in inflammatory processes, we determined the ability of substance P to promote human fibroblast chemotaxis. Cell migration was measured by two different assay types in modified Boyden chambers. Substance P was found to be a potent chemoattractant for human fibroblasts in vitro, eliciting a concentration-dependent migratory response. In further investigations we tested the chemoattractant potency of the fragments substance P-(1-4) and substance P-(3-11). As only the C-terminal analog promoted migratory responses, we suggest that the chemotactic responsiveness is largely encoded by the C-terminus of the neuropeptide, which is known to be active on neurokinin receptors. Involvement of neurokinin receptors of type 1 in the chemotactic response to substance P was indicated by fibroblast migration toward optimal concentration of a selective NK1 receptor agonist but not a NK2 receptor agonist. The observed ability of human fibroblasts to respond chemotactically to substance P elucidated another proinflammatory activity of this neuropeptide.