|The gonadotroph cells in the anterior pituitary gland secrete luteinizing hormone (LH). A sudden rise of LH triggers ovulation and development of the corpus luteum in females. Therefore, it is essential to regulate menstrual cycle. In males, it stimulates Leydig cell production of testosterone. It acts along with FSH in the process of reproduction.The impact factor of journal provides quantitative assessment tool for grading, evaluating, sorting and comparing journals of similar kind. It reflects the average number of citations to recent articles published in science and social science journals in a particular year or period, and is frequently used as a proxy for the relative importance of a journal within its field. It is first devised by Eugene Garfield, the founder of the Institute for Scientific Information. The impact factor of a journal is evaluated by dividing the number of current year citations to the source items published in that journal during the previous two years.