Effect of Inhibition of Mu Opioid Receptor in The VMH on Ovarian Cyst Formation By Morphine In The Rat

Mohammadreza Jalali Nadoushan | Manizheh Karami | Sedigheh Zarei

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URL :   http://research.shahed.ac.ir/WSR/WebPages/Report/PaperView.aspx?PaperID=85462
Date :  2018/04/25
Publish in :    4th International congress on reproduction

Link :  http://www.irciran.com
Keywords :Morphine, Polycystic ovary, Mu opioid receptor, MgSO4, Naloxone, VMH, Rat

Abstract :

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Introduction: The main action of the opioid system is the relief of pain. The discovery of the opioid system stems from the use of opium in ancient history. Opium contains at least 20 types of alkaloids among which morphine is the most important alkaloids which make up about 10-12. According to United Nations statistics, more than 200 million people are dependent on drugs. Most drugs dependent women, including morphine, have irregular menstruation cycles. Drugs may have adverse effects on the reproductive system. Studies have shown that morphine causes ovarian cysts. Ovarian cyst is one of the causes of reproductive failure. Infertility is a major concern in polycystic ovary syndrome (PCOS).Morphine disrupts the ovarian cycle and may reduce fertility. The mu receptor plays a special role in various aspects of female reproduction. Genetically, the mu receptor is one of the most important drug effect sites on the brain. Removal of mu opioid receptors causes mice to be insensitive to morphine. In this study the aim is to use MgSO4 or naloxone to inhibit the mu receptor engagement at the rat’s VMH. Materials & Methods: Female rats (200-250 g) kept under standard conditions. Using a Stereotactic device, they were surgically coordinated. Anterior- posterior: -1/92, ventral: 9, lateral: 0/5. After a week of recovery they were microinjected morphine (0/1-0/4 µg/rat, once intra VMH) and preinjected MgSO4 (1-5 µg/rat) and naloxone hydrochloride (0/1-0/4 µg/rat, once intra VMH) to inhibit mu receptor involvement. The control group received physiological saline (1 µL/rat, intra VMH). Three days after the experiment, uterus, ovary and brain samples were collected and studied histopathologically using hematoxylin & eosin. Results: The ovaries in group in which morphine was injected showed poly cystic features as compared to the control group. With the presence of MgSO4 or naloxone poly cystic ovary was not observed. Discussion & Conclusions: These results indicate that morphine disrupts fertility. This effect is most probably is resolved by mu opioid signaling blocking.

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