RESUMEN
Two hundred and twenty-four pigs (112 boars, 112 gilts) housed in pens of seven pigs per pen were used in a 2 x 2 x 2 factorial design, with the factors of vaccination with a gonadotropin-releasing factor (GnRF) vaccine (Improvac; 0 or 2 mL at 13 and 17 wk of age), porcine somatotropin (pST; 0 or 5 mg/d from 17 wk of age), and gender. Pigs were weighed and feed intake was measured from 17 wk of age until slaughter at 21 wk of age. Body composition was estimated by dual-energy X-ray absorptiometry in two focus pigs per pen at 17 and 21 wk of age. Testes and ovary weights at slaughter were decreased by Improvac treatment (P < 0.001), but were not altered by pST treatment (P > 0.44). Daily gain was lower for gilts than boars (1,128 vs. 1,299 g/d, P < 0.001) and was increased by pST (1,172 vs. 1,255 g/d, P = 0.003) and Improvac (1,150 vs. 1,276 g/d, P < 0.001) treatments. Feed intake (as-fed basis) was lower in gilts than in boars (2,774 vs. 3,033 g/d, P = 0.002), was decreased by pST (3,037 vs. 2,770 g/ d, P = 0.002), and was increased by Improvac treatment (2,702 vs. 3,105 g/d, P < 0.001). As a result of the differences in feed intake and daily gain, feed conversion efficiency (gain:feed) was lower for gilts than for boars (0.403 vs. 0.427 P = 0.025), was improved by pST (0.385 vs. 0.452, P < 0.001), but was unchanged by Improvac treatment (0.423 vs. 0.410, P = 0.22). Carcass weight was lower in gilts than in boars (75.3 vs. 77.0 kg, P = 0.012), was unchanged by pST treatment (75.9 vs. 76.4 kg, P = 0.40), and was increased by Improvac treatment (75.1 vs. 77.2 kg, P = 0.003). Lean tissue deposition rate was lower in gilts than in boars (579 vs. 725 g/d, P < 0.001), was increased by pST (609 vs. 696 g/d, P < 0.001) and by Improvac treatment (623 vs. 682 g/d, P = 0.014). Fat deposition rate tended to be lower in gilts than in boars (214 vs. 247 g/d, P = 0.063), decreased by pST treatment (263 vs. 198 g/d, P < 0.001), and increased by Improvac treatment (197 vs. 264 g/d, P < 0.001). For pigs treated with both pST and Improvac, daily gain and lean tissue deposition rate was greater than for pigs that received either treatment alone, whereas fat deposition rate and feed intake did not differ from untreated control pigs. In conclusion, Improvac increased growth rate through increased lean and fat deposition, but concomitant use of Improvac and pST increased lean gain above either alone, while negating the increase in fat deposition in pigs treated with Improvac.
Asunto(s)
Composición Corporal/efectos de los fármacos , Hormona Liberadora de Gonadotropina/inmunología , Hormona del Crecimiento/administración & dosificación , Inmunización/veterinaria , Porcinos/crecimiento & desarrollo , Absorciometría de Fotón/veterinaria , Tejido Adiposo/crecimiento & desarrollo , Animales , Composición Corporal/fisiología , Sinergismo Farmacológico , Femenino , Masculino , Distribución Aleatoria , Maduración Sexual , Vacunas/administración & dosificación , Aumento de Peso/efectos de los fármacosRESUMEN
Nine analogues of methotrexate, in which the side chain is modified by replacement of the terminal glutamyl moiety with other amino acids, were synthesized from 2,4-diamino-6-(chloromethyl)pteridine. None of these compounds exhibited significant activity against L1210.
Asunto(s)
Antineoplásicos/síntesis química , Metotrexato/análogos & derivados , Animales , Carcinoma 256 de Walker/tratamiento farmacológico , Leucemia L1210/tratamiento farmacológico , Metotrexato/síntesis química , Metotrexato/farmacología , Metotrexato/uso terapéutico , Ratones , Ratas , Relación Estructura-ActividadRESUMEN
Nine tripeptide analogues of methotrexate were synthesized from 2,4-diamino-6-(chloromethyl)pteridine. Only N-[N-[4-[2,4-diamino-6-pteridinyl)methyl]amino]benzoyl]glycyl-DL-aspartic acid (1a) showed moderate activity against L1210 murine leukemia (ILS = 69%) and W 256 carcinosarcoma (TGI = 55%).