Isolation and identification of midkine and pleiotrophin in bovine follicular fluid.
Ovarian factors that promote growth of vascular smooth muscle cells were investigated. Two distinct heparin-binding polypeptides were isolated from bovine follicular fluid by successive chromatographies. N-Terminal and tryptic peptide fragment analysis of these polypeptides revealed that they are identical to midkine (MK) and pleiotrophin (PTN), respectively, which form a new family of heparin-binding growth/differentiation factors. Two N-terminally distinct forms of midkine were also identified in the bovine follicular fluid. The concentrations of MK and PTN in the bovine follicular fluid were estimated to be 125 micrograms/l and 400 micrograms/l, respectively. The present findings that MK and PTN are quite rich in the follicular fluid will provide a new insight into so far unclarified functions of MK and PTN, especially their roles in the maturation of ovarian follicles.
Second Department of Internal Medicine, Gunma University School of Medicine, Japan.
Y
Y
Ohyama
K
K
Miyamoto
N
N
Minamino
H
H
Matsuo
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis / Q000737:chemistry; D000818:Animals; D002352:Carrier Proteins / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D002417:Cattle; D002455:Cell Division / Q000502:physiology; D002478:Cells, Cultured; D002846:Chromatography, Affinity; D002851:Chromatography, High Pressure Liquid; D016207:Cytokines / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D015571:Follicular Fluid / Q000737:chemistry*; D006133:Growth Substances / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D000078792:Midkine; D008969:Molecular Sequence Data; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000187:drug effects; D006080:Ovarian Follicle / Q000502:physiology; D017421:Sequence Analysis
D000596:Amino Acids; D002352:Carrier Proteins; D016207:Cytokines; D006133:Growth Substances; C066845:pleiotrophin; D000078792:Midkine