Chemical characterization of angiotensin I in porcine follicular fluid.
In the search for novel neuropeptides in porcine follicular fluid (pff) using smooth muscle contractile activity as a response parameter, a substance with a marked activity was isolated in a pure form. By amino acid analysis and sequential study, this substance has been chemically revealed to be angiotensin I. A much smaller amount of additional activity was isolated and found to be angiotensin II, as determined by radioimmunoassay. Radioimmunoassays for angiotensin I and II confirmed that the amount of angiotensin I determined was much greater than that of angiotensin II. A comparative study of the extractions, however, indicated a large amount of angiotensin I had been generated from angiotensinogen by endogenous renin in the follicular fluid which could be activated during extraction and ultrafiltration at a low pH. These findings are consistent with the previous reports that described a high concentration of prorenin in the follicular fluid, acid activation of prorenin to renin and the subsequent generation of angiotensin I from endogenous angiotensinogen.
Miyata
A
A
US-Japan Biomedical Research Laboratories, Tulane University Hebert Center, Bell Chasse, LA 70037.
Ge
L J
LJ
Minamino
N
N
Arimura
A
A
D000595:Amino Acid Sequence; D000803:Angiotensin I / Q000032:analysis; D000818:Animals; D001681:Biological Assay; D005260:Female; D015571:Follicular Fluid / Q000032:analysis*; D006168:Guinea Pigs; D066298:In Vitro Techniques; D008969:Molecular Sequence Data; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects; D011863:Radioimmunoassay; D013552:Swine
D000803:Angiotensin I