Androgens and Related Compounds in the Spermatic Vein Blood of Domestic Animals

Abstract

Testosterone, androstenedione and 17\g=a\-hydroxyprogesterone were identified as secretory products of the bull testis by concurrent analyses of the arterial and spermatic vein blood.The testes of prepuberal calves aged 3-6 months (86-200 kg. body weight) were shown to secrete testosterone at rates varying from 14 to 231 \g=m\g.hr./ testis. In calves of less than 125 kg. body weight, the testicular venous blood contained androstenedione in amounts exceeding those of testosterone, whereas in calves above 175 kg. in body weight and in mature bulls the androstenedione/testosterone ratio was well below 1:10. Administration of human chorionic gonadotrophin (HCG; 2000 i.u./48 hr., intramuscularly, for 7 weeks) did not abolish the high androstenedione/testosterone ratio which characterizes the secretion of the immature bull testis.Intravenous administration of HCG to mature bulls (2-5 i.u./kg.) was followed within 20 min. by an increased output of testosterone into the * be < 1\m=.\5 \ g = m \ g . %. Dehydroepiandrosterone was not detectable in the spermatic vein blood by a method sensitive to a plasma concentration of 5-10 \g=m\g.% of this steroid.

Spermatic Vein Testosterone in Boars During Puberty

“…We observed little evidence of epitestosterone (androst-4-en-17oc-ol-3-one) in the extracts analysed. Previous studies by Lindner (1961c) have shown that epitestosterone, as well as testosterone, can be formed by the inherent enzyme activity of whole blood on androstenedione. This activity was shown by Lindner to be present in the blood of the ox and sheep, but was not found in non-ruminant species such as pig, horse and man.…”

Partition of Androgen Between the Lymph and Venous Blood of the Testis in the Ram

“…Apparatus and reagents used for the chemical determination of testosterone and androst-4-ene-3,17-dione (androstenedione) were as described earlier (Lindner & Mann, 1960;Lindner, 1961a), except that the instrument used for scanning radiochromatograms in the present study was an Actigraph II, operated in conjunction with a D. 47 gas-flow counter (Nuclear Chicago Co.), and 14C-4-testosterone (California Co. for Biological Research) was of higher specific activity (21-6 mc./m-mole); the radiochemical purity of this sample was 99%. The counter-current distribution step adopted in the earlier method was replaced by a solvent partition (Finkelstein, 1952 ;Brown, 1955) which makes it possible to determine oestrogens and neutral steroids of varying polarity in the same extract, as shown by Short (1960a).…”

“…2045 ) for chromatography. The Chromatographie separation and spectrophotometric determination of the androgenic steroids was carried out as described previously (Lindner, 1961a).…”

Seasonal Changes in the Testicular Blood Flow of Seasonally Breeding Mammals: Dormouse, Glis Glis, Ferret, Mustella Furo, and Fox, Vulpes Vulpes

“…As the initia¬ tion of spermatogenesis is under pituitary control, it has been suggested that 'the vascular growth may be under the control of gonadotrophins or other anterior pituitary hormones' (Waites & Setchell, 1969;Setchell, 1970). Nevertheless, it is generally agreed that gonadotrophins have no immediate effect on the total venous blood flow through the testes of dogs, rams, boars and stallions (Lindner, 1961;Eik Nes, 1964) or on the testicular capillary blood flow of rams (Setchell, 1970).…”