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Electroacupuncture enhances extragonadal aromatization in ovariectomized rats.

Zhao H, Tian Z, Cheng L, Chen B - Reprod. Biol. Endocrinol. (2004)

Bottom Line: To explore the source of the increased circulation estrogen, the extragonadal aromatization was detected.The blood concentrations of estrogen, testosterone and corticosterone were measured by radioimmunoassay.Both the subcutaneous abdominal adipose and the liver tissues contributed to the effects of electroacupuncture on the extragonadal aromatization to promote the blood concentrations of estrogen in the ovariectomized rats.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Neurobiology and Integrative Medicine, Institute of Acupuncture Research , WHO Collaborating Center for Traditional Medicine, Shanghai Medical College of Fudan University, Shanghai, P R China. zh2000h@hotmail.com

ABSTRACT

Background: Repeated electroacupuncture (EA) stimulation is known to stimulate the activity of the hypothalamus-pituitary-adrenal axis, and to enhance the circulation level of estrogen in the ovariectomized rats. To explore the source of the increased circulation estrogen, the extragonadal aromatization was detected.

Methods: Female rats were divided into five groups: 1) intact (INT), 2) intact with EA in specific points (INT+EA), 3) ovariectomized (OVX), 4) ovariectomized with EA in specific points (OVX+EA) and 5) ovariectomized with EA in non-specific points (OVX+C). Radiometric assay, Western blot and RT-PCR were adopted to determine the extragonadal aromatization in subcutaneous abdominal (SA) adipose and liver tissues of rats. The blood concentrations of estrogen, testosterone and corticosterone were measured by radioimmunoassay.

Results: The aromatase activities of the SA adipose and liver tissues in the OVX+EA rats increased significantly (p < 0.01) compared with those in the INT, INT+EA and OVX rats. The 58-kDa aromatase protein and aromatase mRNA expressions normalized to beta-actin in the OVX+EA rats' SA adipose tissues showed higher levels than those from corresponding tissues in the INT and INT+EA rats (p < 0.05). And the ratios of aromatase mRNA and protein to beta-actin in the OVX+EA rats' liver tissues increased significantly compared with those in the OVX rats (p < 0.05). Furthermore, blood estrogen and corticosterone concentrations showed significant increase in the OVX+EA rats compared with the concentrations in the OVX and OVX+C rats (p < 0.05), but no statistical disparity occurred on the blood testosterone concentrations between the OVX+EA rats and the OVX ones.

Conclusion: Both the subcutaneous abdominal adipose and the liver tissues contributed to the effects of electroacupuncture on the extragonadal aromatization to promote the blood concentrations of estrogen in the ovariectomized rats.

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The aromatase activities in SA adipose and liver tissues of the INT (n = 12), INT+EA (n = 12), OVX (n = 12) and OVX+EA (n = 10) rats. ***p < 0.01 vs INT, INT+EA and OVX.
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Figure 3: The aromatase activities in SA adipose and liver tissues of the INT (n = 12), INT+EA (n = 12), OVX (n = 12) and OVX+EA (n = 10) rats. ***p < 0.01 vs INT, INT+EA and OVX.

Mentions: The tissues were incubated with (1β-3H) androstenedione for various periods of time, and the production of 3H2O (aromatase activity) was linear with time up to 1 h of incubation. The aromatase activity was also linear with increasing amounts of tissue up to 5 mg/incubation. The optimal pH for the aromatase was 7.4. The maximum rates were obtained with a substrate concentration of 0.2 μM, and the enzyme preparation exhibited an apparent Michaelis-Menten constant (Km) of 0.04 μM. Therefore, incubation conditions were optimised that tissue homogenates ~3 mg tissue/ incubation; and incubation for 1 h in 0.2 ml potassium phosphate buffer containing 0.13 μM substrate (pH 7.4). The aromatase activity of the SA adipose and liver tissues presented no changes among the INT, INT+EA and OVX, and the activity of the SA adipose and liver tissue in the OVX+EA increased significantly (p < 0.01) compared with that in the INT, INT+EA and OVX (Fig. 3).


Electroacupuncture enhances extragonadal aromatization in ovariectomized rats.

Zhao H, Tian Z, Cheng L, Chen B - Reprod. Biol. Endocrinol. (2004)

The aromatase activities in SA adipose and liver tissues of the INT (n = 12), INT+EA (n = 12), OVX (n = 12) and OVX+EA (n = 10) rats. ***p < 0.01 vs INT, INT+EA and OVX.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC411058&req=5

Figure 3: The aromatase activities in SA adipose and liver tissues of the INT (n = 12), INT+EA (n = 12), OVX (n = 12) and OVX+EA (n = 10) rats. ***p < 0.01 vs INT, INT+EA and OVX.
Mentions: The tissues were incubated with (1β-3H) androstenedione for various periods of time, and the production of 3H2O (aromatase activity) was linear with time up to 1 h of incubation. The aromatase activity was also linear with increasing amounts of tissue up to 5 mg/incubation. The optimal pH for the aromatase was 7.4. The maximum rates were obtained with a substrate concentration of 0.2 μM, and the enzyme preparation exhibited an apparent Michaelis-Menten constant (Km) of 0.04 μM. Therefore, incubation conditions were optimised that tissue homogenates ~3 mg tissue/ incubation; and incubation for 1 h in 0.2 ml potassium phosphate buffer containing 0.13 μM substrate (pH 7.4). The aromatase activity of the SA adipose and liver tissues presented no changes among the INT, INT+EA and OVX, and the activity of the SA adipose and liver tissue in the OVX+EA increased significantly (p < 0.01) compared with that in the INT, INT+EA and OVX (Fig. 3).

Bottom Line: To explore the source of the increased circulation estrogen, the extragonadal aromatization was detected.The blood concentrations of estrogen, testosterone and corticosterone were measured by radioimmunoassay.Both the subcutaneous abdominal adipose and the liver tissues contributed to the effects of electroacupuncture on the extragonadal aromatization to promote the blood concentrations of estrogen in the ovariectomized rats.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Neurobiology and Integrative Medicine, Institute of Acupuncture Research , WHO Collaborating Center for Traditional Medicine, Shanghai Medical College of Fudan University, Shanghai, P R China. zh2000h@hotmail.com

ABSTRACT

Background: Repeated electroacupuncture (EA) stimulation is known to stimulate the activity of the hypothalamus-pituitary-adrenal axis, and to enhance the circulation level of estrogen in the ovariectomized rats. To explore the source of the increased circulation estrogen, the extragonadal aromatization was detected.

Methods: Female rats were divided into five groups: 1) intact (INT), 2) intact with EA in specific points (INT+EA), 3) ovariectomized (OVX), 4) ovariectomized with EA in specific points (OVX+EA) and 5) ovariectomized with EA in non-specific points (OVX+C). Radiometric assay, Western blot and RT-PCR were adopted to determine the extragonadal aromatization in subcutaneous abdominal (SA) adipose and liver tissues of rats. The blood concentrations of estrogen, testosterone and corticosterone were measured by radioimmunoassay.

Results: The aromatase activities of the SA adipose and liver tissues in the OVX+EA rats increased significantly (p < 0.01) compared with those in the INT, INT+EA and OVX rats. The 58-kDa aromatase protein and aromatase mRNA expressions normalized to beta-actin in the OVX+EA rats' SA adipose tissues showed higher levels than those from corresponding tissues in the INT and INT+EA rats (p < 0.05). And the ratios of aromatase mRNA and protein to beta-actin in the OVX+EA rats' liver tissues increased significantly compared with those in the OVX rats (p < 0.05). Furthermore, blood estrogen and corticosterone concentrations showed significant increase in the OVX+EA rats compared with the concentrations in the OVX and OVX+C rats (p < 0.05), but no statistical disparity occurred on the blood testosterone concentrations between the OVX+EA rats and the OVX ones.

Conclusion: Both the subcutaneous abdominal adipose and the liver tissues contributed to the effects of electroacupuncture on the extragonadal aromatization to promote the blood concentrations of estrogen in the ovariectomized rats.

Show MeSH