PMID- 1360927
OWN - NLM
STAT- MEDLINE
DCOM- 19930108
LR  - 20190813
IS  - 0303-7207 (Print)
IS  - 0303-7207 (Linking)
VI  - 88
IP  - 1-3
DP  - 1992 Oct
TI  - Somatostatin binding and modulation of adenylate cyclase in ovine retina 
      membranes.
PG  - 111-7
AB  - Somatostatin (SS) receptors in membranes from ovine retinas were examined using 
      125I-Tyr11-SS as a ligand. Receptor binding was rapid, specific, saturable, 
      reversible and dependent on temperature and membrane concentration. Conditions of 
      apparent equilibrium were obtained at 25 degrees C after a 45 min incubation in 
      the presence of about 0.25 mg membrane protein/ml. Native SS competitively 
      inhibited the binding of 125I-Tyr11-SS in the range of 0.01-10 nM, and 
      half-maximal inhibition was observed at 0.2 nM SS. Scatchard analysis of these 
      data suggested the existence of a single population of SS receptors with a 
      dissociation constant of 0.23 +/- 0.03 nM and a maximum binding capacity of 84 
      +/- 6 fmol/mg protein. The binding of 125I-Tyr11-SS was inhibited by various 
      synthetic SS analogs in a dose-dependent manner whereas peptides unrelated to SS 
      did not show practically any effect even at concentrations as high as 10(-6) M. 
      SS receptor occupancy appears to be coupled to inhibition of adenylate cyclase 
      activity by a guanine nucleotide-binding regulatory protein, as suggested by the 
      facts that: (a) SS noncompetitively inhibited the stimulatory effect of 
      vasoactive intestinal peptide (VIP) (3 x 10(-7) M) on membrane adenylate cyclase 
      activity but it did not alter basal enzyme activity; and (b) the addition of 
      guanosine 5'-triphosphate (GTP) (10(-5) M) decreased the specific binding of 
      125I-Tyr11-SS to 26.6% of the control value due to a decrease in SS receptor 
      affinity. The present results support the hypothesis that SS may contribute to 
      the physiological regulation of the functions of the retina.
FAU - Colas, B
AU  - Colas B
AD  - Department of Biochemistry and Molecular Biology, Medical School, University of 
      Alcala, Madrid, Spain.
FAU - Valencia, A M
AU  - Valencia AM
FAU - Prieto, J C
AU  - Prieto JC
FAU - Arilla, E
AU  - Arilla E
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - Ireland
TA  - Mol Cell Endocrinol
JT  - Molecular and cellular endocrinology
JID - 7500844
RN  - 0 (Receptors, Somatostatin)
RN  - 51110-01-1 (Somatostatin)
RN  - 59481-27-5 (somatostatin, Tyr(11)-)
RN  - 86-01-1 (Guanosine Triphosphate)
RN  - EC 4.6.1.1 (Adenylyl Cyclases)
SB  - IM
MH  - Adenylyl Cyclases/*metabolism
MH  - Amino Acid Sequence
MH  - Animals
MH  - Binding, Competitive
MH  - Cell Membrane/drug effects/enzymology
MH  - Depression, Chemical
MH  - Enzyme Activation/drug effects
MH  - Guanosine Triphosphate/pharmacology
MH  - Kinetics
MH  - Molecular Sequence Data
MH  - Receptors, Somatostatin/drug effects/*metabolism
MH  - Retina/*drug effects/enzymology
MH  - Sheep
MH  - Somatostatin/analogs & derivatives/*metabolism/pharmacology
EDAT- 1992/10/01 00:00
MHDA- 1992/10/01 00:01
CRDT- 1992/10/01 00:00
PHST- 1992/10/01 00:00 [pubmed]
PHST- 1992/10/01 00:01 [medline]
PHST- 1992/10/01 00:00 [entrez]
AID - 0303-7207(92)90015-X [pii]
AID - 10.1016/0303-7207(92)90015-x [doi]
PST - ppublish
SO  - Mol Cell Endocrinol. 1992 Oct;88(1-3):111-7. doi: 10.1016/0303-7207(92)90015-x.