title: Vasoactive intestinal peptide stimulation of human trabecular meshwork cell growth.
abstract: OBJECTIVE
  To demonstrate that vasoactive intestinal peptide (VIP), a 28-amino acid neuropeptide, is a growth factor of human trabecular meshwork (TM) cells in culture and in a corneoscleral explant organ culture treated with laser trabeculoplasty (LTP).
  
  
  METHODS
  Proliferating human TM cells in cell cultures were incubated with VIP for 20 hours, followed by total cell number determination, using a Coulter counter. The percentage of proliferating TM cells was assessed, using an antibody against the proliferating cell nuclear antigen (PCNA). To test the growth effect of VIP on TM cells in situ, corneoscleral explants in organ cultures were first treated with argon LTP to initiate TM-cell proliferation and then were exposed to VIP for 48 hours. The mitotic TM cells were demonstrated immunocytochemically, using anti-PCNA in paraffin sections of the explants; and the total number of TM cells was determined after paraffin sections were counterstained by hematoxylin.
  
  
  RESULTS
  Vasoactive intestinal peptide dose-dependently stimulated the proliferation of TM cells in cell culture. Treatment with 5 x 10(-10) M VIP resulted in a maximal increase of 40% in cell number. The effect of VIP was blocked by a VIP antagonist. The number of PCNA-stained TM cells and the total cell number in the TM in LTP-treated corneoscleral explants were increased by VIP.
  
  
  CONCLUSIONS
  Exogenously applied VIP stimulated the proliferation of human TM cells in subconfluent cultures and in LTP-treated corneoscleral explants. In that LTP has been shown to increase the number of TM cells in situ, the growth stimulatory effect of VIP may help enhance this therapy.
authors.affiliation: Department of Ophthalmology, University of Maryland at Baltimore 21201, USA.
authors.forename: S W
authors.initials: SW
authors.lastname: Koh
authors.forename: T H
authors.initials: TH
authors.lastname: Yeh
authors.forename: S M
authors.initials: SM
authors.lastname: Morris
authors.forename: M
authors.initials: M
authors.lastname: Leffler
authors.forename: E J
authors.initials: EJ
authors.lastname: Higginbotham
authors.forename: D E
authors.initials: DE
authors.lastname: Brenneman
authors.forename: B Y
authors.initials: BY
authors.lastname: Yue
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002452:Cell Count; D002455:Cell Division / Q000187:drug effects*; D002478:Cells, Cultured; D002648:Child; D003315:Cornea / Q000166:cytology / Q000187:drug effects / Q000378:metabolism / Q000601:surgery; D004305:Dose-Response Relationship, Drug; D006133:Growth Substances / Q000494:pharmacology*; D006801:Humans; D007124:Immunoenzyme Techniques; D053685:Laser Therapy; D008938:Mitosis / Q000187:drug effects; D009924:Organ Culture Techniques; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism; D012590:Sclera / Q000166:cytology / Q000187:drug effects / Q000378:metabolism / Q000601:surgery; D014129:Trabecular Meshwork / Q000166:cytology* / Q000378:metabolism / Q000601:surgery; D014130:Trabeculectomy; D014660:Vasoactive Intestinal Peptide / Q000494:pharmacology*
chemical_list: D006133:Growth Substances; D018809:Proliferating Cell Nuclear Antigen; D014660:Vasoactive Intestinal Peptide