Reference

Influence of anabolic treatments on luteinizing hormone and testosterone secretion in bulls

Influence of anabolic treatments on luteinizing hormone and testosterone secretion in bulls. Fabry, J.; Renaville, R.; Burny, A. (Stn. Zootech., Cent. Rech. Agron., Gembloux B-5800, Belg.). Anim. Prod., 39(3), 345-54 (English) 1984. CODEN: ANIPA8. ISSN: 0003-3561. DOCUMENT TYPE: Journal CA Section: 18 (Animal Nutrition) Section cross-reference(s): 2 Growing Belgian White Blue bulls were assigned to 3 groups: controls (C); bulls implanted with 140 mg trenbolone acetate [10161-34-9] and 36 mg Zeranol [26538-44-3] (TBA-Z); and bulls implanted with 140 mg trenbolone acetate and 20 mg estradiol-17b [50-28-2] (TBA-E2). Testosterone (T) [58-22-0] and LH [9002-67-9] levels in blood plasma were detd. at day 0, 30, and 60. Mean plasma LH concns. measured by repeated sampling over a 10-h period were similar at day 0, 30, and 60 in the 3 groups. At days 30 and 60, T levels were lowered in treated bulls: namely 2.0 vs. 2.7 mg/L, 0.7 vs. 1.0 mg/L, and 0.5 vs. 0.4 mg/L in the C, TBA-Z, and TBA-E2 groups, resp. Moreover, anabolic compds. completely abolished pulsatile liberation of LH and T. In control bulls i.v. injection of LH-RH [9034-40-6] (0.5 mg/kg) caused the release of a large quantity of LH (10-13 times the basal level after 10 min) followed by an increase in plasma T levels. On the other hand, LH and T responses to LH-RH were reduced by TBA-E2 and TBA-Z treatments. A delay in LH response to LH-RH was apparent 6 days after anabolic treatment. However, the total amt. of LH liberated during the test was increased. The 2nd effect was a quant. redn. at days 20, 30, and 60 in LH and T secretion after LH-RH. The modification of the hormonal pattern was quicker and more pronounced in TBA-E2 than in TBA-Z animals. Correlation was neg. between the mean daily gain during the exptl. period and the total quantity of T liberated by the testis after LH-RH stimulation at day 60. Thus, administration of trenbolone acetate plus Zeranol or trenbolone acetate plus estradiol-17b in pubertal bulls reduced the LH and T responses to LH-RH and abolished the pulsatile LH and T secretions.

Trenbolone levels in tissues of trenbolone acetate-implanted steers: radioimmunoassay determination using different antiserums

Trenbolone levels in tissues of trenbolone acetate-implanted steers: radioimmunoassay determination using different antiserums. O'Keeffe, M. (Agric. Inst., Dunsinea Res. Cent., Dublin, Ire.). Br. Vet. J., 140(6), 592-9 (English) 1984. CODEN: BVJOA9. ISSN: 0007-1935. DOCUMENT TYPE: Journal CA Section: 2 (Mammalian Hormones) Section cross-reference(s): 17 Muscle, kidney, liver, and fat tissue samples from steers on prodn. systems incorporating implantation with the anabolic agent trenbolone acetate [10161-34-9], were assayed for residues of trenbolone [10161-33-8]. Two antisera, one a specific trenbolone antiserum and the other a 17b-trenbolone specific antiserum, were used to det. residue levels in tissue exts. by RIA. Both antisera distinguished between treated and control animals on assay of muscle, kidney, and fat, but not on liver. Reside levels detd. in muscle, kidney, and fat samples from animals implanted 2 mo before slaughter were higher than residue levels in these tissues from nonimplanted animals. Repeated implantation, at 9 mo and at 2 mo before slaughter, did not result in higher residue levels compared with animals implanted only once, at 2 mo before slaughter. Significant correlations were found for residue levels between different tissues (within a single assay) and between the 2 assays for each tissue type.