Clinical Data Supporting the Importance of Vascular LH/hCG Receptors of Uterine Blood Vessels

ABSTRACT

Recent studies revealed functional extragonadal gonadotropin receptors at several sites of the human body. The human chorionic gonadotropin/luteinizing hormone (hCG/LH) receptor messenger RNA and protein were found in the endothelial and vascular smooth muscle layers of the human uterine arteries. In vivo administration of hCG decreased the blood flow resistance in the human uterus and in vitro increased vasodilating eicosanoids in the vascular wall. These findings initiated a further study investigating whether the administration of hCG to patients with signs of threatened abortion has any beneficial effect. The patients were treated with either magnesium or progesterone and/or hCG. The results showed that the rate of patients reaching second trimester was higher when hCG was included in the treatment protocol, and a parallel significant decrease in uterine blood flow resistance was also found. Analyzing the long-term results, the rate of preterm and growth-retarded deliveries was lower when hCG was administered in the first trimester. As a conclusion, the uterine vascular LH/hCG receptors play a significant role in the peri-implantation period. The hCG might also participate in angiogenesis, enhancing long-term clinical results.

KEYWORD

Human chorionic gonadotropin - uterine artery - blood flow resistance - threatened abortion

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