A Na pump inhibitor from bovine posterior pituitary: purification, structure determination and its cardiovascular effect in rat.
We examined the hypothesis that hypothalamo-hypophysial tissue contains an endogenous Na pump inhibitor. From bovine posterior pituitary, we purified a substance which inhibits Rb uptake by human erythrocytes. This inhibitory activity was found in the eluate of 10% acetonitrile from a C18 flash column and purified by subsequent three steps of reversed-phase high-performance liquid chromatography (HPLC). Sequence analysis revealed that this substance was identical to joining peptide, one of the major products of proopiomelanocortin (POMC). This peptide had hypertensive and tachycardiac effects in spontaneously hypertensive rats (SHR) after central administration, with weak Na,K-ATPase inhibitory activity (IC50 = 0.5 mM).
Hamakubo
T
T
Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232.
Furuta
H
H
Ichimura
M
M
Appalsamy
M
M
Mosqueda-Garcia
R
R
Robertson
D
D
Inagami
T
T
D000595:Amino Acid Sequence; D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D001794:Blood Pressure / Q000187:drug effects*; D002417:Cattle; D002845:Chromatography; D002851:Chromatography, High Pressure Liquid; D004912:Erythrocytes / Q000187:drug effects / Q000378:metabolism*; D006339:Heart Rate / Q000187:drug effects*; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D010446:Peptide Fragments; D010455:Peptides / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D010904:Pituitary Gland, Posterior / Q000737:chemistry / Q000502:physiology*; D011333:Pro-Opiomelanocortin / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D012413:Rubidium / Q000097:blood; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors* / Q000502:physiology*
D010446:Peptide Fragments; D010455:Peptides; C078895:joining peptide, pro-opiomelanocortin; D011333:Pro-Opiomelanocortin; D000254:Sodium-Potassium-Exchanging ATPase; D012413:Rubidium