Androgen concentration in the blood and spermatogenic function of tom cats during the breeding season

In order to better understand androgen secretion in the tom cat during the breeding season, observations of diurnal changes in peripheral blood testosterone (T) levels, were made and the relation between androgen levels (androstenedione (A), 5α-dihydrotestosterone (DHT), T) in testicular and peripheral vein blood was borne. Histologic examinations of the testis were also performed to investigate spermatogenic function. The 9 tom cats used in these studies were 2-3 years old, weighed 3.5-4.0kg, and were raised in a room under natural lighting. As a result, diurnal peripheral blood T levels in the tom cat fluctuated greatly according to each individual, but since no definite trend could be identified, secretion was determined to be episodic. Although fairly large differences in the 3 types of androgen were observed in testicular vein blood depending on the individual animal, levels on the left and right were almost equal. Moreover, a correlation was found between the testicular and peripheral vein blood concentrations of the 3 androgens (A: p