H1 and H2 histamine receptors in N-nitroso-N-methylurea (NMU)-induced carcinomas with atypical coupling to signal transducers

Biochem Pharmacol. 1995 Jun 29;50(1):91-6. doi: 10.1016/0006-2952(95)00108-c.


Two specific binding sites for histamine were characterized in the cell membrane of N-nitroso-N-methylurea (NMU)-induced tumors. The first one, with higher affinity (Kd = 4 +/- 2 nM), was further identified as an H2 type, while the lower affinity one (35 +/- 10 nM) corresponded to an H1 receptor. Histamine concentrations up to 50 nM, as well as H2 agonists, significantly enhanced the phosphoinositide turnover by acting through higher affinity H2 receptors. On the other hand, histamine at concentrations over 50 nM and H1 agonists produced a 100% increase in cAMP levels in a response specifically blocked by mepyramine. These H1 and H2 histamine receptors that exhibit different linkages to second messenger systems may prove to be a characteristic of cells with a high proliferating capacity, such as undifferentiated or transformed cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Female
  • Mammary Neoplasms, Experimental / chemically induced
  • Mammary Neoplasms, Experimental / metabolism*
  • Mammary Neoplasms, Experimental / pathology
  • Methylnitrosourea
  • Rats
  • Rats, Sprague-Dawley
  • Receptors, Histamine H1 / metabolism*
  • Receptors, Histamine H2 / metabolism*
  • Signal Transduction*


  • Receptors, Histamine H1
  • Receptors, Histamine H2
  • Methylnitrosourea