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Estrone sulfatase activity in guinea pig tissues
Journal of Steroid Biochemistry
|July 1, 1982
Summary
Estrone sulfatase activity is found in many guinea pig tissues, with highest levels in microsomes. This enzyme differs from rat liver arylsulfatase C in its inhibition patterns and steroid sensitivity.
Area of Science:
- Biochemistry
- Enzymology
- Comparative Physiology
Background:
- Estrone sulfatase is a key enzyme in steroid metabolism.
- Understanding its tissue distribution and properties is crucial for metabolic research.
- Previous studies have characterized arylsulfatase C in rat liver.
Purpose of the Study:
- To investigate the tissue distribution and biochemical properties of estrone sulfatase in guinea pig tissues.
- To compare the guinea pig enzyme with rat liver arylsulfatase C.
- To examine developmental and pregnancy-related changes in enzyme activity.
Main Methods:
- Homogenization and subcellular fractionation of various guinea pig tissues.
- Assay of estrone sulfatase activity across different tissues and fractions.
- Kinetic analysis, including pH optima and Km values.
- Inhibition studies using inorganic phosphate, sulfate, steroids, and diethylstilbestrol (DES).
Main Results:
- Estrone sulfatase activity is widespread in guinea pig tissues, with highest specific activity in adult testis, uterus, lung, adrenal, and ovary.
- Microsomes showed the highest specific activity, but significant activity was also found in large cellular fragments.
- The enzyme shares some properties with rat liver arylsulfatase C, such as pH optimum and Km values, but differs in inhibition by inorganic phosphate and steroid sensitivity.
- Diethylstilbestrol (DES) showed less inhibition in guinea pig tissues compared to rat liver.
- Fetal estrone sulfatase activity decreased from neonatal to adult life in lung, kidney, and liver, while testicular activity increased.
- Pregnancy did not significantly alter uterine enzyme activity.
Conclusions:
- Guinea pig estrone sulfatase exhibits a distinct tissue distribution and biochemical profile compared to rat liver arylsulfatase C.
- The enzyme's sensitivity to phosphate inhibition and lower steroid sensitivity are key differentiating factors.
- Developmental trends in estrone sulfatase activity vary by tissue, suggesting complex regulatory mechanisms.