PMID- 11485004
OWN - NLM
STAT- MEDLINE
DCOM- 20020122
LR  - 20190921
IS  - 0742-3098 (Print)
IS  - 0742-3098 (Linking)
VI  - 31
IP  - 1
DP  - 2001 Aug
TI  - Acute modulation of somatostatin receptor function by melatonin in the rat 
      frontoparietal cortex.
PG  - 46-56
AB  - Since melatonin (N-acetyl-5-methoxytryptamine) decreases locomotor activity and 
      rearing and increases grooming behavior in a similar manner as somatostatin 
      (SRIF), we examined if melatonin could induce these changes through 
      somatostatinergic neurotransmission in the rat frontoparietal cortex. Male Wistar 
      rats (200-250 g) received a single injection of melatonin (25 microg/kg per day) 
      subcutaneously (s.c.) and were sacrificed 5 hr later. Melatonin treatment 
      increased the number of 125I-Tyr11-SRIF receptors in frontoparietal cortical 
      membranes without any changes in the dissociation constant (Kd). The capacity of 
      SRIF to inhibit basal and forskolin (FK)-stimulated adenylyl cyclase (AC) 
      activity was increased in melatonin-treated rats as compared to the control 
      animals. Melatonin administration also induced a lower AC activity, both under 
      basal conditions and after stimulation of the enzyme via stimulatory guanine 
      nucleotide-binding proteins (Gs), or directly with FK. Functional inhibitory 
      guanine nucleotide-binding protein (Gi) activity was increased in frontoparietal 
      cortical membranes from melatonin-treated rats when compared to controls. Western 
      blot analyzes showed that melatonin administration did not alter the amount of 
      the Gialpha1, or Gialpha3 subunits, but reduced Gialpha2 levels in frontoparietal 
      cortical membranes. No significant changes in SRIF-like immunoreactivity content 
      and SRIF mRNA levels were detected in this brain area after melatonin treatment. 
      Administration of the melatonin receptor antagonist luzindole (10 mg/kg, s.c.) 30 
      min before melatonin injection did not change the melatonin-induced effects on 
      the SRIF receptor effector system. In conclusion, the present results show that 
      acute melatonin administration increases the activity of the SRIF receptor 
      effector system and decreases Gialpha2 levels in the rat frontoparietal cortex. 
      In addition, the coupling of Gs to AC is disturbed by melatonin.
FAU - Izquierdo-Claros, R M
AU  - Izquierdo-Claros RM
AD  - Departamento de Bioquimica y Biologia Molecular, Facultad de Medicina, 
      Universidad de Alcala, Madrid, Spain.
FAU - Boyano-Adanez, M C
AU  - Boyano-Adanez MC
FAU - Torrecillas, G
AU  - Torrecillas G
FAU - Rodriguez-Puyol, M
AU  - Rodriguez-Puyol M
FAU - Arilla-Ferreiro, E
AU  - Arilla-Ferreiro E
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - England
TA  - J Pineal Res
JT  - Journal of pineal research
JID - 8504412
RN  - 0 (RNA, Messenger)
RN  - 0 (Receptors, Somatostatin)
RN  - 51110-01-1 (Somatostatin)
RN  - EC 3.6.5.1 (GTP-Binding Protein alpha Subunits, Gi-Go)
RN  - EC 3.6.5.1 (GTP-Binding Protein alpha Subunits, Gs)
RN  - EC 4.6.1.1 (Adenylyl Cyclases)
RN  - JL5DK93RCL (Melatonin)
SB  - IM
MH  - Adenylyl Cyclases/metabolism
MH  - Animals
MH  - Frontal Lobe/*drug effects/metabolism
MH  - GTP-Binding Protein alpha Subunits, Gi-Go/metabolism
MH  - GTP-Binding Protein alpha Subunits, Gs/metabolism
MH  - Kinetics
MH  - Male
MH  - Melatonin/*pharmacology
MH  - Parietal Lobe/*drug effects/metabolism
MH  - RNA, Messenger/genetics/metabolism
MH  - Rats
MH  - Rats, Wistar
MH  - Receptors, Somatostatin/*drug effects/metabolism
MH  - Somatostatin/genetics/metabolism
EDAT- 2001/08/04 10:00
MHDA- 2002/01/23 10:01
CRDT- 2001/08/04 10:00
PHST- 2001/08/04 10:00 [pubmed]
PHST- 2002/01/23 10:01 [medline]
PHST- 2001/08/04 10:00 [entrez]
AID - 10.1034/j.1600-079x.2001.310107.x [doi]
PST - ppublish
SO  - J Pineal Res. 2001 Aug;31(1):46-56. doi: 10.1034/j.1600-079x.2001.310107.x.