PMID- 2110844
OWN - NLM
STAT- MEDLINE
DCOM- 19900620
LR  - 20190613
IS  - 0006-8993 (Print)
IS  - 0006-8993 (Linking)
VI  - 507
IP  - 2
DP  - 1990 Jan 22
TI  - Effects of long-term theophylline treatment on adenosine A1-receptors in rat 
      brain: autoradiographic evidence for increased receptor number and altered 
      coupling to G-proteins.
PG  - 195-9
AB  - The effects of 2 weeks' treatment with theophylline (20 mg/kg i.p.) on the 
      binding to adenosine A1-receptors was studied by autoradiography using the 
      agonist [3H]N6-cyclohexyladenosine ([3H]CHA) and the antagonist 
      [3H]8-cyclopentyl-1,3-dipropylxanthine ([3H]DPCPX) as ligands. A significant 
      increase (10%) in [3H]CHA binding was measured only in the frontoparietal cortex. 
      However, if the brain sections were incubated in the presence of 5 microM 
      guanosine-5'-triphosphate (GTP), which by itself decreased binding by between 15 
      and 80% depending on the region, the increase in the frontoparietal cortex was 
      larger (30%) and significant increases of the same magnitude were also seen in 
      several other structures, e.g. the caudate putamen and the central gray matter of 
      the midbrain. In some regions, for example the hippocampus and the cerebellar 
      cortex, small or no increases were seen. GTP 100 microM practically eliminated 
      [3H]CHA binding in both control and treated animals, suggesting that these 
      receptors are all coupled to G-proteins. The binding of [3H]DPCPX was increased 
      significantly only in the frontoparietal and striate cortex (5-10%). These 
      results suggest that the theophylline treatment had little on the total receptor 
      number but may have altered the coupling between A1-receptors and regulatory 
      GTP-binding proteins.
FAU - Fastbom, J
AU  - Fastbom J
AD  - Department of Pharmacology, Karolinska Institutet, Stockholm, Sweden.
FAU - Fredholm, B B
AU  - Fredholm BB
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - Netherlands
TA  - Brain Res
JT  - Brain research
JID - 0045503
RN  - 0 (Receptors, Purinergic)
RN  - 0 (Xanthines)
RN  - 36396-99-3 (N(6)-cyclohexyladenosine)
RN  - 9PTP4FOI9E (1,3-dipropyl-8-cyclopentylxanthine)
RN  - C137DTR5RG (Theophylline)
RN  - EC 3.6.1.- (GTP-Binding Proteins)
RN  - K72T3FS567 (Adenosine)
SB  - IM
MH  - Adenosine/analogs & derivatives/metabolism
MH  - Animals
MH  - Autoradiography
MH  - Brain/drug effects/*metabolism
MH  - GTP-Binding Proteins/*metabolism
MH  - Male
MH  - Rats
MH  - Rats, Inbred Strains
MH  - Receptors, Purinergic/drug effects/*metabolism
MH  - Theophylline/*administration & dosage
MH  - Xanthines/metabolism
EDAT- 1990/01/22 00:00
MHDA- 1990/01/22 00:01
CRDT- 1990/01/22 00:00
PHST- 1990/01/22 00:00 [pubmed]
PHST- 1990/01/22 00:01 [medline]
PHST- 1990/01/22 00:00 [entrez]
AID - 0006-8993(90)90272-D [pii]
AID - 10.1016/0006-8993(90)90272-d [doi]
PST - ppublish
SO  - Brain Res. 1990 Jan 22;507(2):195-9. doi: 10.1016/0006-8993(90)90272-d.