RESUMO
This investigation was carried out to determine the effects of bursectomy on in vitro response of adrenal glands to adrenocorticotropic hormone (ACTH) and testes to human chorionic gonadotropin (HCG) in immature male chickens. One-day-old Single Comb White Leghorn male chicks were surgically bursectomized (BSX). Sham-operated (sham) chicks were used as controls. At 5 wk of age, adrenal cortical cells (ACC) from BSX and sham birds were incubated in vitro with various concentrations (0, 10(-7), 10(-6), and 10(-5) M) of ACTH for 2 h, and then corticosterone was measured in all supernatants. At 15 wk of age, Leydig cells from testes of both groups were incubated in vitro with HCG (3,000 IU/mL) for 3 h, and then testosterone was measured in all supernatants. Corticosterone concentrations in response to both 10(-6) and 10(-5) ACTH were significantly lower for BSX than for sham ACC. Leydig cells from sham birds produced significantly more testosterone than those of BSX birds whether or not the cells were stimulated with HCG. Furthermore, Leydig cells from sham birds, but not from BSX birds, produced significantly more testosterone when stimulated with HCG than when saline was added. These results indicated that the bursa of Fabricius or its products might have a stimulatory effect on the response of ACC and Leydig cells to ACTH and HCG, respectively.
Assuntos
Glândulas Suprarrenais/metabolismo , Hormônio Adrenocorticotrópico/farmacologia , Bolsa de Fabricius/cirurgia , Galinhas/metabolismo , Gonadotropina Coriônica/farmacologia , Células Intersticiais do Testículo/metabolismo , Glândulas Suprarrenais/citologia , Glândulas Suprarrenais/efeitos dos fármacos , Animais , Corticosterona/metabolismo , Células Intersticiais do Testículo/efeitos dos fármacos , Masculino , Testículo/citologia , Testículo/efeitos dos fármacos , Testículo/metabolismo , Testosterona/metabolismoRESUMO
Experiments were carried out to study the effect of an extended light period (natural, gradual, and abrupt) on the semen characteristics, fertility, and hatchability of Pekin ducks. The results obtained can be summarised as follows: 1. Night feeding has no reliable effect on the semen production and characteristics in drakes. Thus, any improvement in the semen characteristics of different treated groups compared to the control may be traced back to light stimulus only. 2. Light stimulus showed a favourable effect on the semen volume and sperm motility, concentration, viability and normality during the two laying seasons. 3. Subjection of ducks to artificial light had a favourable effect on their fertility and hatchability.
