Immunohistochemical Localization of AT_1a, AT_1b, and AT₂ Angiotensin II Receptor Subtypes in the Rat Adrenal, Pituitary, and Brain with a Perspective Commentary

Table 1

Tabulated summary of comparative regional and cellular distribution of Ang II receptor-immunoreactivity in rat brain and pituitary.

Region	AT1a	AT1b	AT2
Neocortex
Lamina I-II	ND	0^+/5*	1^+/1*
Lamina III-IV	ND	4^+/5*	0^+/4*
Lamina V-VI	ND	4^+/4*	3^+/3*
Basal (Anterior) Forebrain
Entorhinal cortex	2^+/0*	0^+/0*	5^+/1*
Hippocampus
CA1	1^+/0*	ND	4^+/5*
CA3	1^+/0*	ND	5^+/5*
Dentate Gyrus	ND	ND	2^+/2*
Central Amygdala	1^+/0*	ND	4^+/3*
Caudate nucleus	3^+/1*	1^+/0*	5^+/3*
Thalamus
Medial Dorsal Thalamus	0^+/0*	0^+/0*	5^+/2*
Periventricular nucleus of the thalamus	0^+/0*	0^+/0*	3^+/5*
Medial Habenula	1^+/0*	0^+/0*	5^+/3*
Lateral Habenula	0^+/0*	0^+/0*	0^+/0*
Septal Area
Dorsal Median preoptic nucleus	2^+/3*	3^+/4*	4^+/5*
Medial Septum	0^+/0*	0^+/0*	0^+/2*
Lateral Septum	2^+/1*	1^+/1*	2^+/0*
Hypothalamus
Anterior Hypothalamic Area	2^+/3*	1^+/1*	3^+/4*
Lateral Hypothalamic Area	3^+/2^+	4^+/5*	3^+/0*
Paraventricular nucleus	4^+/0*	5^+/5*	5^+/3*
Periventricular area	3^+/0*	2^+/5	5^+/0*
Suprachiasmatic nucleus	1^+/0*	0^+/0*	2^+/5*
Arcuate nucleus	5^+/4*	5^+/5*	4^+/0*
Circumventricular Organs/Pituitary
Median Eminence	0^+/2*	0^+/3*	0^+/4^+
Subfornical Organ	4^+/5*	0^+/2*	3^+/5*
Area Postrema	3^+/0*	4^+/4*	3^+/4*
Posterior Pituitary (pars nervosa)	0^+/3*	0^+/2*	ND
Anterior Pituitary (pars distalis)	0^+/0*	5^+/0*	5^+/0*
Stellate cells	0^+/0*	5^+/0*	1^+/0*
Ovoid cells	0^+/0*	1^+/0*	4^+/0*
Cerebellum
Purkinje Cells	0^+/0*	5^+/5*	ND
Hindbrain
RVLM	4^+/2*	2^+/2*	ND
NTS	3^+/4*	5^+/2*	3^+/4*

Key: ⁺refers to neuronal cell bodies/*refers to fibers. Scored on a scale from 0 to 5. ND is not determined. No AT_1a immunoreactivity was observed in glia. AT_1b and AT₂ immunoreactivity were observed in glia.