[Effects of hormonal replacement therapy on colon anastomosis healing in rats].
OBJECTIVE
The symptoms of the climacteric coincide with the marked appearance of signs of skin aging. Studies on animal models have shown that estrogen is a critical mediator in wound healing. The authors report a study of the influence of hormonal replacement therapy (HRT) on colon anastomoses performed in female rats.


METHODS
Three groups of Wistar rats were used: one submitted to oophorectomy and receiving HRT with 50 mg estrogen and 2 mg medroxyprogesterone acetate, one submitted to oophorectomy without HRT, and one of laparotomized but not oophorectomized rats. Hormonal condition was confirmed 28 days after oophorectomy and HRT or physiological saline was then administered daily. Left colotomy was performed after 2 months with end-to-end anastomosis, and resistance and collagen density were determined after 7 and 14 days.


RESULTS
the anastomoses of the colons of rats receiving no HRT were less resistant than those of the control group both on the 7th (p = 0.0488) and 14th (p = 0.0115) day. Collagen density was lower on the 7th day (p = 0.0210), with a lower presence of collagen I (p = 0.0023) and collagen III (p = 0.0470), and these differences continued to be significant on the 14th day. The colon anastomoses of rats receiving HRT did not differ significantly from control.


CONCLUSIONS
The lack of ovarian hormones leads to a lower resistance and delays the maturation of colon anastomosis in rats and these deficiencies are compensated for by HRT.
Biondo-Simões
Maria de Lourdes Pessole
Mde L
Disciplina de Técnica Cirúrgica e Cirurgia Experimental da Universidade Federal do Paraná. biondo@avalon.sul.com.br
Zimmermann
Elise
E
Daher
Tatiana Sato
TS
Borsato
Karin Soldatelli
KS
de Noronha
Lucia
L
D000714:Anastomosis, Surgical; D000818:Animals; D003094:Collagen / Q000187:drug effects; D003106:Colon / Q000601:surgery*; D003271:Contraceptive Agents, Female / Q000008:administration & dosage*; D004195:Disease Models, Animal; D015914:Estrogen Replacement Therapy; D004966:Estrogens, Conjugated (USP) / Q000008:administration & dosage*; D005260:Female; D008365:Manometry; D017258:Medroxyprogesterone Acetate / Q000008:administration & dosage*; D010052:Ovariectomy; D051381:Rats; D017208:Rats, Wistar; D013718:Tensile Strength / Q000187:drug effects; D014945:Wound Healing / Q000187:drug effects*
D003271:Contraceptive Agents, Female; D004966:Estrogens, Conjugated (USP); D003094:Collagen; D017258:Medroxyprogesterone Acetate