摘要:

Cyclic AMP and cGMP phosphodiesterase (PDE) activities and nucleic acid contents were assayed in crude homogenates prepared from biopsies excised between days 39 and 162 of gestation (normal full length of gestation: 165 days) in outer and inner layers of the macaque myometrium. In both layers, kinetic analysis of PDE indicated high (apparent Km 2 × 10––6M) and low (apparent Km 2 × 10––5M) affinity component for each substrate. When measured in high-affinity conditions, specific activities were elevated around day 40 and beyond day 130 of gestation. By contrast, low values were observed between days 50 and 100. They were related to the decrease of the Vmax values (expressed either per milligram protein or per microgram DNA). No significant differences were observed between outer and inner layers. Variations of tissue DNA and RNA were demonstrated throughout gestation indicating that both hyperplasia and hypertrophy were involved in uterine growth. Unlike DNA, RNA content (and consequently the RNA:DNA ratio) in the inner layer always remained above the values of the outer layer. In both layers, the RNA:DNA ratio, which presumably reflects the rate of protein synthesis and the PDE activity, reached maximum values at the

ISSN:0378-7346    

DOI:10.1159/000299007

出版商:S. Karger AG    

年代:1985

数据来源: Karger

ISSN:0378-7346    

DOI:10.1159/000284255

出版商:S. Karger AG    

年代:1904

数据来源: Karger

摘要:

In the present study the effect of methoxamine and its modification by several adrenergic antagonists is described in the isolated oestrogenized rat uterus. Methoxamine produced a dose-related increase in uterine activity, prazosin produced a rightward displacement of the dose-response curve of methoxamine reaching the same maximal effect. Yohimbine abolished the contractile response to methoxamine. Propranolol or reserpine failed to modify the effect of methoxamine. Pretreatment with reseφine abolished the inhibitory effect of yohimbine. These results suggest the presence of excitatory α-adrenoceptors in the rat uterus.

ISSN:0378-7346    

DOI:10.1159/000299008

出版商:S. Karger AG    

年代:1985

数据来源: Karger

ISSN:0378-7346    

DOI:10.1159/000284257

出版商:S. Karger AG    

年代:1904

数据来源: Karger

ISSN:0378-7346    

DOI:10.1159/000284258

出版商:S. Karger AG    

年代:1904

数据来源: Karger

ISSN:0378-7346    

DOI:10.1159/000284259

出版商:S. Karger AG    

年代:1904

数据来源: Karger

ISSN:0378-7346    

DOI:10.1159/000284260

出版商:S. Karger AG    

年代:1904

数据来源: Karger

ISSN:0378-7346    

DOI:10.1159/000284261

出版商:S. Karger AG    

年代:1904

数据来源: Karger

ISSN:0378-7346    

DOI:10.1159/000284262

出版商:S. Karger AG    

年代:1904

数据来源: Karger

ISSN:0378-7346    

DOI:10.1159/000284263

出版商:S. Karger AG    

年代:1904

数据来源: Karger