Negative Feed Back Regulation of Oestrogen & Vasodilatory Function of Progesterone Responsible for Preovulatory Gonadotropin Surge [LH Surge] - A Hypothesis
Journal Title: Journal of Medical Science And clinical Research - Year 2015, Vol 3, Issue 4
Abstract
At present there are many universal observations related to GnRH pulse & Gonadotropins surge in female. The explanation regarding the possible cause of preovulatory LH surge is not clear. An effort is made to explain this, with help of multiple experimental & human study observations as follows First peak of oestrogen occurring 24hrs prior to ovulation Inhibition of GnRH at Hypothalamus. FSH + LH [from gonadotropes of pituitary] Oestrogen [from Theca interna cells] Regain of GnRH secretory pulse after 15hrs. 3½ times increased secretion of gonadotropins as preovulatory surge . This surge has decreased ratio of LH : total gonadotropins In conclusion “preovulatory gonadotropins’ surge” is better word used than “preovulatory LH surge”. There is one gonadotropin surge with one pulse of GnRH with LH content of 67% in follicular, 57% in preovulatory & 90% in luteal phases. Increase in LH content in luteal phase is due to vasodilatory effect of progesterone causing better hypothalamo – hypophyseal portal circulation, providing better nutrition supply of aminoacids [AA] favouring conversion of FSH to LH. The subunit of FSH with addition of 3 AA. gets converted to LH i.e. 112 AA in FSH & 115 AA in LH. Inspite of removal of inhibitory effect of 2nd peak of oestrogen on GnRH, Gonadotropins’ surge does not occur. This may be due to generalized vasoconstriction caused by sudden withdrawal of progesterone, resulting in poor nutrition of secretory cells of hypothalamus & pituitary
Authors and Affiliations
Dr. Asha A. Dharwadkar
Keywords
Related Articles
- EP ID EP209065
- DOI -
- Views 68
- Downloads 0
A Clinical Study of Risk Factors of Coronary Artery Disease including newer Risk Factors in Elderly Patients
Coronary artery disease (CAD) is the result of the accumulation of atheromatous plaques within the walls of the coronary arteries. CAD is one of the most common cause of morbidity and mortality in different communities....
Potential application of Harmonic Scalpel in Laparoscopic Cholecystectomy as an alternative to Monopolar electrocautery
The Laparoscopic Cholecystectomy (LC) is the gold standard treatment modality for uncomplicated acute or chronic cholecystitis with cholelithiasis. Conventional LC is normally performed with a Monopolar electrocautery wh...
Comparative Study of Attenuation of Hemodynamic Changes during Laryngoscopy and Intubation Using Intravenous lidocaine and Intravenous Dexmedetomidine in Patients Undergoing Abdominal Surgery
Background: Ligocaineis an aminoethylamide, a prototype of amide local anaesthetic group and its IV uses blunted pressure response to intubation. 1.5 mg/kg lignocaine 3 min prior to intubation has shown good result. Dexm...
Knowledge and Attitude on Sexually Transmitted Infections among Young Adults in Kerala
Background: Sexually Transmitted Infections (STI's) and HIV mainly affects sexually active adolescents and young people. Young adults aged 15-29 years, account for 32% of AIDS cases reported in India and the number of yo...
Anatomical Prevalence of Fractures among Admitted Patients in a Tertiary Care Hospital: A Retrospective Study
Introduction: The aim of this study is to determine the anatomical distribution of fractures among admitted patients in a tertiary care hospital. Methods: This is a retrospective study of patients admitted in Government...