| Popis: |
Immunocytochemical approaches have achieved an outstanding level for characterizing angiotensinergic systems in the brain and periphery. The development of affinity-purified antibodies for angiotensin II has resulted in distinct loss of background activity and produced discrete staining of neurons and small angiotensinergic fibres. The improvement of immunocytochemical techniques has enhanced the ability to develop maps of angiotensinergic pathways. Furthermore, the production of specific monoclonal antibodies to angiotensin receptor subtypes, such as AT1 and AT2, has led to the characterization and localization of angiotensin hormonal and neurotransmitter systems in brain and peripheral tissues. Such affinity-purified antibodies have revealed that angiotensin and vasopressin are colocalized in hypothalamo-neurohypophysial systems, implying that both peptides are released together in the median eminence and the neurohypophysis. Recent studies have shown that in spite of using the same antigen molecule for immunization as well as for affinity purification, different staining pattern are obtained, suggesting that the different carrier proteins forced the production of different antibodies to different epitopes. Furthermore, the finding supports the hypothesis that angiotensin II is not the only effector peptide in the renin-angiotensin system but a member of a family of biologically active angiotensinergic peptides. The presented studies support once more that immunocytochemical approaches remain important tools for characterizing angiotensinergic systems in the central nervous and peripheral tissues. |
