期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1981
卷号：78
期号：10
页码：6154-6157
DOI：10.1073/pnas.78.10.6154
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Responses of smooth muscle to kallikreins (EC 3.4.21.8) are generally considered to result from kinin formation. This premise was reexamined with the isolated rat uterus. Rat urinary kallikrein or bradykinin produced dose-dependent contractions of rat uterus but kallikrein was 5-fold more potent than bradykinin. Kallikrein caused an immediate series of rhythmic contractions which could be increased gradually with subsequent addition of kininogen substrate. Kallikrein-induced contractions were unaffected by carboxypeptidase B or a bradykinin antiserum whereas bradykinin-induced contractions were attenuated or abolished. Other serine proteinases, including trypsin, either did not induce contraction in the absence of added kininogen or did so minimally. Although small amounts of kininogen-like substrate were found in uterine tissue, detectable kinin levels (greater than 4 pg) could not be found in bathing media during maximal kallikrein-induced contractions or after uterine tissue was incubated with high concentrations of the enzyme in the presence of SQ 20881, a kininase II inhibitor. The data suggest that uterine contraction produced by a homologous kallikrein does not involve kinin formation but results from an action of this serine proteinase upon other accessible systems coupled to the contractile response.
