Deficient activity of nucleotide binding regulatory protein coupled with PGE2 receptor in renal medulla of spontaneously hypertensive rats.
Prostaglandin (PG) E2 receptor-adenylate cyclase system was studied in the kidney of 12-week-old spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKY) to evaluate the role of this system in hypertension. PGE2 receptors were determined by a radioligand binding method using [3H]-PGE2. Adenylate cyclase responses to PGE2, sodium fluoride (NaF) and forskolin were also measured. The concentration of PGE2 receptor was increased in SHR compared with WKY. PGE2- and NaF-stimulated adenylate cyclase activities were significantly lower in SHR than WKY. There was no significant difference in forskolin-stimulated adenylate cyclase activity between SHR and WKY. NaF activates the nucleotide binding regulatory protein (G-protein) and forskolin directly activates the catalytic unit. These results indicate that the activity of G-protein coupled with renal PGE2 receptors is deficient in SHR. This defect may contribute to the elevation of blood pressure, through sodium retention.
Yoshikawa
H
H
Department of Medicine, Wakayama Medical College, Japan.
Fukuda
K
K
Baba
A
A
Nishio
H
H
Ueyama
T
T
Yoshikawa
A
A
Kuchii
M
M
Nishio
I
I
Masuyama
Y
Y
D000262:Adenylyl Cyclases / Q000502:physiology*; D000818:Animals; D005576:Colforsin / Q000494:pharmacology; D015232:Dinoprostone; D019204:GTP-Binding Proteins / Q000502:physiology*; D006973:Hypertension / Q000503:physiopathology*; D007679:Kidney Medulla / Q000503:physiopathology*; D008297:Male; D011458:Prostaglandins E / Q000502:physiology; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D011982:Receptors, Prostaglandin / Q000032:analysis / Q000187:drug effects*; D012969:Sodium Fluoride / Q000494:pharmacology
D011458:Prostaglandins E; D011982:Receptors, Prostaglandin; D005576:Colforsin; D012969:Sodium Fluoride; D019204:GTP-Binding Proteins; D000262:Adenylyl Cyclases; D015232:Dinoprostone