Mammalian Ovulation

Release of oocyte from the ovary is called ovulation. Various process involved in ovulation have been described (Wani, 1996, 2008) some of its main features are reproduced in following pages. A recent hypothesis has been put forth by well known reproductive physiologist of repute Prof. Espey, II of Taxas fame. The ovulation processes in mammalian species are regarded as an inflammatory reaction. The conditions which lead to the rupture of an ovulatory follicles have been described. Espey, 2009 concrete evidences show that tense connective tissue preovulatory follicle wall gets softened. Both its tunica externa get weakened, before follicle wall breaks down releasing oocyte. The process known as ovulations. Many evidences of this breakup are known and reported. The intra follicular pressure as a result of antrum being filled with follicular fluid. Once this fluid accumulates it tends to loosen the connective tissue wall. This thinning process is now postulated to be resulted or resulting into transformation quiescent thecal fibroblasts into migrating cell. These migrating cells are thus comparable to well known inflammatory reactions.

The question arise as to what triggered this transformation. As on date the factor metabolic, immunogeneic or genetic which stimulate or initiate this transformation of fibroblast is not certain. Infective agent plays its role in an inflammatory process. As up to this stage all intrinsic self involving genetic codes are operative, what makes the fibroblasts act overse as if to reaction to a non-self protein need investigation and shall be our main focus in this chapter. Most of the basic events of ovulation's have been discussed in subtitle to this chapter "Preclude to Ovulation".

Women ovulates usually during mid cycle i.e. day 14 of a 28 menstrual cycle. One released eggs can wait for sperm 48 hrs. Sometimes the wait is short and ends in 12 hrs depending on the endocrinology and status female. After 48 hrs it disintegrates. He is most receptive during the days around ovulation. Sex on these days makes greater possibility of fertility. The day of menstruation or bleeding is usually 14th day of ovulation. We can work out the day for a women who has 30 day cycle. She will ovulate around day 16 (30-14=16) day 1 is the first day of your next period.

Physical symptoms of ovulation in women can be tested as;

-Increased basal body temperature
-Cervical mucus change and mucus increased,
-Lower abdominal pain easily moving

Body temperature increase, cervical mucus stretchable and clear or slippery are the indications of ovulation's.

Some women feel mild aching to sharp pain. These symptoms called Mittel Schmerz Symptoms last from few minutes to few hours. Usually right side of abdomen feels the pain.

During most fertile period of a women her cervical mucus is like white of an egg- clear and slippery. This is ovulation day. Cervix in women can not be felt by middle finger on ovulation as it is high up on the day.

During dioestrus-I these is a functional relationship between the chollinertgic and dopaminergic system in preoptic anterior hypothalamic area, regulating the release of luteinizing hormone resulting in ovulation (Merica et al. 2001).

Mammalian ovulation thus beings with rupture of the ovulatory follicle. Ovary has an endocrine and exocrine function. Exocrine relates to release of "ova" at ovulation and endocrine relates to production and synthesis of progesterone from its constituent body corpus luetum. This corpus luetum develop after ovulation. Primodial follicles stay in dormancy till puberty. At puberty menstruation in women and oestrus in animals signals advent of cyclicity and resultant ovulation. The ovulation process and time differs in different mammalian species. A few charts and fingers are shown at the end of this chapter to understand the process. The GnRH initiates the act. This stimulates pituitary which release FSH and LH. A mature follicle at the time of rupture process the following structure.

Oocyte at its first meiotic division, divides into two unequal cells. One is released as first polar body and resultant oocyte is called secondary oocyte. It contains all cytoplasmic material of both daughter cell. Before it the ovulating follicle thinning or blister formation is felt per rectum in bovines. A 15 mm follicles usually feel as a blister and finds a place devoid of many blood vessels on the ovary. A protrusion called stigma was seen (Wani 1984) in sheep via laparoscoy. Follicular fluid ooze out form the stigma releasing the ova.

The second meiotic division is without DNA replication and remains at metaphase until fertilization spindle shaped 2nd polar body is released at ovulation and if oocyte is not released follicle under foes degenerate and distortion.

Ovulation Enzymes

A full article on ovarian enzyme and ovulation has been published in Biology of Reproduction as easly as 1974 in Espey for ovulation tests are available like

-Pregnancy and ovulation strips
-Baby hopes ovulation strips
-Radio Immunoassay and many other

by DR PARAS WANI MD DEICINE
Dr g.m.wani Ph.D.DMV,
DR GAZANFER WANI MBBS
DR T.ZAHIR.BUMS

References

Palmieri, R.T, Wilson, MA, Iverson, E.S, Clyde, MA, Calingaert, B, Moorman, G Poole, C, Anderson, AR, Anderson, S and Anton H, 2008
Polymorphism in the ILI8 gene and epithellal ovarian cancer in non-hispanic white women. Cancer epidimal. Biomarkers Prev. 17 (12): 3567-3572

Zaho, P, De A, HU, Z Mulder, SM Solewijn, MD, Gelple, EK, Dilan and Hsueh, A JW. 2008
Gonodotrophin stimulation of ovarian fractalkine expression and fractalkine augmentation of progesterone biosynthesis by luteinizing granulosa cells. Endcrinology 149 (6) : 2782-2789