Electrophysiological evidence for receptors for vasoactive intestinal peptide and angiotensin II on astrocytes of cultured rat central nervous system.
Electrophysiological studies have been made of the actions of vasoactive intestinal peptide (VIP) and angiotensin II (Ang II) on astrocytes in explant cultures of rat brain stem and spinal cord. Addition of VIP to the bathing solution at concentrations of 10(-8) to 10(-6) M caused hyperpolarizations. Ang II at the same concentrations depolarized the majority of astrocytes tested. At 10(-9) M, both peptides had no action or only small effects. In approximately one third of the cells, the depolarizations by Ang II were accompanied by rhythmic oscillations. The Ang II antagonist saralasin reversibly blocked the depolarizations by Ang II. These findings, together with autoradiographic binding studies from our laboratory strongly suggest the existence of VIP and Ang II receptors on astrocytes.
Hösli
L
L
Department of Physiology, University of Basel, Switzerland.
Hösli
E
E
Heuss
L
L
Rojas
J
J
D000804:Angiotensin II / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D057911:Angiotensin Receptor Antagonists; D000818:Animals; D001253:Astrocytes / Q000502:physiology*; D001933:Brain Stem / Q000166:cytology / Q000502:physiology; D002478:Cells, Cultured; D004594:Electrophysiology; D008564:Membrane Potentials; D051381:Rats; D011945:Receptors, Angiotensin / Q000502:physiology*; D011964:Receptors, Gastrointestinal Hormone / Q000502:physiology*; D018005:Receptors, Vasoactive Intestinal Peptide; D012504:Saralasin / Q000494:pharmacology; D013116:Spinal Cord / Q000166:cytology / Q000502:physiology; D014660:Vasoactive Intestinal Peptide / Q000494:pharmacology*
D057911:Angiotensin Receptor Antagonists; D011945:Receptors, Angiotensin; D011964:Receptors, Gastrointestinal Hormone; D018005:Receptors, Vasoactive Intestinal Peptide; D000804:Angiotensin II; D014660:Vasoactive Intestinal Peptide; D012504:Saralasin