Abstract
While many autonomic and metabolic defects associated with genetic obesity in the Zucker rat are corrected by adrenalectomy (Adx), brain adrenoceptor function has not been examined in this context. Here, 3 weeks after Adx or sham surgery, brains of 11 weeks old lean ( Fa Fa) and obese ( fa fa) male Zucker rats were assayed for α1-([3H]prazosin; [3H]PRZ) and α2-adrenoceptor ([3H]paraminoclonidine; [3H]PAC) binding by autoradiography. By genotype, obese rats had 19-256% higher [3H]PRZ binding than lean rats in the amygdala (central [ACN], basolateral [ABL], basomedial [ABM] and medial [MAN] nuclei [n.]), hypothalamus (dorsomedial n. [DMN] and lateral [LH]) and somatosensory cortex. In the ABL and ACN, increased maximal binding(Bmax) in obese rats was associated with decreased affinity (increased Kd). Three weeks after surgery, sham-operated obese rats gained 27% more weight than lean rats but lean and obese Adx rats gained the same amount of weight. Adx reduced [3H]PRZ binding in both lean and obese rats by 37-70% in the amygdala (ABM, ACN, MAN) compared to sham-operated rats. But, Adx selectively reduced [3H]PRZ binding only in lean rats in the ABL, DMN, ventromedial hypothalamic n. (VMN) and ventroposteromedial thalamic n. In most areas, decreases in maximal binding (Bmax) associated with Adx were accompanied by decreases in Kd. Unlike [3H]PRZ binding, there was no consistent genotype difference in [3H]PAC binding although Adx was followed by increased binding in obese and decreased binding in lean rats in the ABL. In only the VMN, obese rats had a 21% higher α2- to α1-adrenoceptor ratio than lean White widespread differences in brain α1-adrenoceptor binding between lean and obese rats may be important, the selectively higher VMN α2-/α1- ratio may be critical to the pathogenesis of obesity.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 146-154 |
| Number of pages | 9 |
| Journal | Brain Research |
| Volume | 614 |
| Issue number | 1-2 |
| DOIs | |
| State | Published - Jun 18 1993 |
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Keywords
- Adrenalectomy
- Adrenoceptor
- Catecholamine
- Corticosterone
- Norepinephrine
- Obesity
ASJC Scopus subject areas
- Developmental Biology
- Molecular Biology
- Clinical Neurology
- Neuroscience(all)
Cite this
Altered α1-adrenoceptor binding in intact and adrenalectomized obese Zucker rats ( fa fa). / Levin, Barry E.; Planas, Barbara; Routh, Vanessa H.; Hamilton, Jock; Stern, Judith S.; Horwitz, Barbara A.
In: Brain Research, Vol. 614, No. 1-2, 18.06.1993, p. 146-154.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Altered α1-adrenoceptor binding in intact and adrenalectomized obese Zucker rats ( fa fa)
AU - Levin, Barry E.
AU - Planas, Barbara
AU - Routh, Vanessa H.
AU - Hamilton, Jock
AU - Stern, Judith S.
AU - Horwitz, Barbara A
PY - 1993/6/18
Y1 - 1993/6/18
N2 - While many autonomic and metabolic defects associated with genetic obesity in the Zucker rat are corrected by adrenalectomy (Adx), brain adrenoceptor function has not been examined in this context. Here, 3 weeks after Adx or sham surgery, brains of 11 weeks old lean ( Fa Fa) and obese ( fa fa) male Zucker rats were assayed for α1-([3H]prazosin; [3H]PRZ) and α2-adrenoceptor ([3H]paraminoclonidine; [3H]PAC) binding by autoradiography. By genotype, obese rats had 19-256% higher [3H]PRZ binding than lean rats in the amygdala (central [ACN], basolateral [ABL], basomedial [ABM] and medial [MAN] nuclei [n.]), hypothalamus (dorsomedial n. [DMN] and lateral [LH]) and somatosensory cortex. In the ABL and ACN, increased maximal binding(Bmax) in obese rats was associated with decreased affinity (increased Kd). Three weeks after surgery, sham-operated obese rats gained 27% more weight than lean rats but lean and obese Adx rats gained the same amount of weight. Adx reduced [3H]PRZ binding in both lean and obese rats by 37-70% in the amygdala (ABM, ACN, MAN) compared to sham-operated rats. But, Adx selectively reduced [3H]PRZ binding only in lean rats in the ABL, DMN, ventromedial hypothalamic n. (VMN) and ventroposteromedial thalamic n. In most areas, decreases in maximal binding (Bmax) associated with Adx were accompanied by decreases in Kd. Unlike [3H]PRZ binding, there was no consistent genotype difference in [3H]PAC binding although Adx was followed by increased binding in obese and decreased binding in lean rats in the ABL. In only the VMN, obese rats had a 21% higher α2- to α1-adrenoceptor ratio than lean White widespread differences in brain α1-adrenoceptor binding between lean and obese rats may be important, the selectively higher VMN α2-/α1- ratio may be critical to the pathogenesis of obesity.
AB - While many autonomic and metabolic defects associated with genetic obesity in the Zucker rat are corrected by adrenalectomy (Adx), brain adrenoceptor function has not been examined in this context. Here, 3 weeks after Adx or sham surgery, brains of 11 weeks old lean ( Fa Fa) and obese ( fa fa) male Zucker rats were assayed for α1-([3H]prazosin; [3H]PRZ) and α2-adrenoceptor ([3H]paraminoclonidine; [3H]PAC) binding by autoradiography. By genotype, obese rats had 19-256% higher [3H]PRZ binding than lean rats in the amygdala (central [ACN], basolateral [ABL], basomedial [ABM] and medial [MAN] nuclei [n.]), hypothalamus (dorsomedial n. [DMN] and lateral [LH]) and somatosensory cortex. In the ABL and ACN, increased maximal binding(Bmax) in obese rats was associated with decreased affinity (increased Kd). Three weeks after surgery, sham-operated obese rats gained 27% more weight than lean rats but lean and obese Adx rats gained the same amount of weight. Adx reduced [3H]PRZ binding in both lean and obese rats by 37-70% in the amygdala (ABM, ACN, MAN) compared to sham-operated rats. But, Adx selectively reduced [3H]PRZ binding only in lean rats in the ABL, DMN, ventromedial hypothalamic n. (VMN) and ventroposteromedial thalamic n. In most areas, decreases in maximal binding (Bmax) associated with Adx were accompanied by decreases in Kd. Unlike [3H]PRZ binding, there was no consistent genotype difference in [3H]PAC binding although Adx was followed by increased binding in obese and decreased binding in lean rats in the ABL. In only the VMN, obese rats had a 21% higher α2- to α1-adrenoceptor ratio than lean White widespread differences in brain α1-adrenoceptor binding between lean and obese rats may be important, the selectively higher VMN α2-/α1- ratio may be critical to the pathogenesis of obesity.
KW - Adrenalectomy
KW - Adrenoceptor
KW - Catecholamine
KW - Corticosterone
KW - Norepinephrine
KW - Obesity
UR - http://www.scopus.com/inward/record.url?scp=0027300772&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0027300772&partnerID=8YFLogxK
U2 - 10.1016/0006-8993(93)91028-Q
DO - 10.1016/0006-8993(93)91028-Q
M3 - Article
C2 - 8394183
AN - SCOPUS:0027300772
VL - 614
SP - 146
EP - 154
JO - Brain Research
JF - Brain Research
SN - 0006-8993
IS - 1-2
ER -