Collection of Rete Testis Fluid from Rats Without Previous Efferent Duct Ligation

Abstract

A method has been developed for collection of rete testis fluid from a rat efferent duct without prior efferent duct ligation. Flow rates averaged 0.64 ± 0.04 SD mI/mm. Pressure in the unligated efferent duct ranged from 1.8-4.5 cm H20. After 14 h of ligation, duct pressure reached 40 cm 1120. Emptying of the rete contents after 16-29 h of efferent duct ligation was biphasic with 30-40% of accumulated fluid draining within 40 mm and a further 20-40% imerging at a much slower rate over the next 4 h. Recovery of more than 60% of theoretical fluid stored within 5 h was rare. Sperm counts from 2 rats with unligated efferent ducts yielded sperm production rates of 28.2 and 34.4 X 10’ sperm/day. After 16-29 h efferent duct ligation sperm concentrations were highest in the initial drainage and fell by 3 1-78% during the early fast drainage phase. Testosterone concentration averaged 24.2 ± 4.0 SD and 20.0 ± 3.5 SD ng/ml for rats without and with efferent duct ligation respectively with no significant difference between the two groups. Testosterone concentration remained constant in successive volume increments of rete fluid after 16 h efferent duct ligation. When sufficient rete fluid volume was available for detection, concentrations of estradiol-17i3 averaged 248 ± 95 pg/mI in unligated rats and 68 ± 42 pg/mI in ligated rats (P<0.05). Additionally, estradiol-17a levels increased more than 5-fold during 3 h drainage of rete fluid after 23 h efferent duct ligation suggesting that estradiol secretion may be suppressed by efferent duct ligation. These studies suggest that collection of rete fluid from laboratory animals without recourse to efferent duct ligation may provide a more physiologic preparation for study of the fluid environment for testicular spermatozoa.