Quantitative autoradiography of angiotensin II receptors in the SHR brain

Journal Article · Sat Nov 01 00:00:00 EST 1986 · Peptides (Fayetteville, N.Y.); (United States)

DOI:https://doi.org/10.1016/0196-9781(86)90132-4· OSTI ID:6527877

Gehlert, D R; Speth, R C; Wamsley, J K

Several lines of evidence indicate brain angiotensin II is associated with the elevation of blood pressure seen in the spontaneously hypertensive rat (SHR). These include an increased pressor response to intracerebroventricularly administered angiotensin II and a reduction of blood pressure in response to centrally administered angiotensin II receptor antagonists. Using quantitative receptor autoradiography, we have detected greater angiotensin II receptor binding in a number of discrete brain nuclei of the 6-week-old SHR when compared to age-matched Wistar-Kyoto controls. Tissue sections from various brain regions were labeled with (/sup 125/I)-angiotensin II according to a previously described method. Autoradiograms were generated by apposing the labeled tissue sections to LKB Ultrofilm along with brain paste standards which contained known amounts of (/sup 125/I). Quantitation of the binding, utilizing computer-assisted microdensitometry, indicated greater (/sup 125/I)-angiotensin II binding in several brain areas implicated in cardiovascular control including the subfornical organ, nucleus of the solitary tract, dorsal motor nucleus of the vagus, locus coeruleus, supraoptic nucleus and the organum vasculosum of the lamina terminalis. Scatchard analysis of the binding in the nucleus of the solitary tract indicated an increased receptor number (Bmax) was responsible for the change while binding in two forebrain structures, the subfornical organ and supraoptic nucleus, showed alterations in receptor number and affinity (Kd). Several other brain regions, unrelated to cardiovascular control, exhibited no change in (/sup 125/I)-angiotensin II binding.

• Research Organization: Univ. of Utah Health Sciences Center, Salt Lake City
• OSTI ID: 6527877
• Journal Information: Peptides (Fayetteville, N.Y.); (United States), Vol. 6
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
ANGIOTENSIN
RECEPTORS
AUTORADIOGRAPHY
BIOCHEMICAL REACTION KINETICS
BIOLOGICAL VARIABILITY
BLOOD PRESSURE
BRAIN
CELL NUCLEI
HYPERTENSION
IODINE 125
RATS
TISSUE DISTRIBUTION
ANIMALS
BETA DECAY RADIOISOTOPES
BODY
CARDIOVASCULAR AGENTS
CARDIOVASCULAR DISEASES
CELL CONSTITUENTS
CENTRAL NERVOUS SYSTEM
DAYS LIVING RADIOISOTOPES
DISEASES
DISTRIBUTION
DRUGS
ELECTRON CAPTURE RADIOISOTOPES
GLOBULINS
INTERMEDIATE MASS NUCLEI
IODINE ISOTOPES
ISOTOPES
KINETICS
MAMMALS
MEMBRANE PROTEINS
NERVOUS SYSTEM
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANS
PROTEINS
RADIOISOTOPES
REACTION KINETICS
RODENTS
SYMPTOMS
VASCULAR DISEASES
VASOCONSTRICTORS
VERTEBRATES
550201* - Biochemistry- Tracer Techniques