Androgen Suppresses Corticotropin-Induced Increase in Plasma Cortisol Level but Enhances The Increase in Plasma Aldosterone Level in Goats

Abstract

ABSTRACT. Previously we reported that androgen treatment reduced the extent of the increase in plasma cortisol (Cor) levels induced by adrenocorticotropic hormone (ACTH) administration in goats. In this study, we investigated the effect of androgen on the plasma levels of androstenedione and aldosterone. Four castrated male goats, which were treated with either 5α-dihydrotestosterone (DHT) or cholesterol (cho), were injected intravenously with 0.005, 0.02 or 0.1 mg of ACTH(1-24). Plasma Cor levels were increased significantly by all doses of ACTH injection, and these extents were lower in DHT-treated goats. Plasma androstenedione levels were also increased by ACTH injection, but DHT treatment seemed to little affect. Plasma aldosterone levels were also increased by ACTH injection, and there were no differences between cho-and DHT treated goats at 15 and 30 min after the ACTH injection. However, when goats were given the lower doses of ACTH (0.02 and 0.005 mg), plasma aldosterone levels were restored rapidly only in cho-treated goats, whereas those in DHT-treated goats were maintained throughout the 60 min experimental period. Consequently, plasma aldosterone levels in DHT-treated goats were higher than those in cho-treated goats at 45 and 60 min. One possible mechanism of the effect of DHT on the ACTH-induced increase in aldosterone synthesis may be the reduction of the activity of P450-17α, that is the enzyme to convert pregnenolone to 17α-OH-pregnenolone, and this mechanism may also be responsible to the suppressive effect of DHT on the ACTH-induced Cor synthesis.

Sodium–glucose cotransporters: Functional properties and pharmaceutical potential

“…Among the class I facilitative transporters, GLUT1 has ubiquitous expression, with abundant expression in the brain and erythrocytes, and moderate expression in fat, muscle and the liver 4,12–14 . GLUT1 is responsible for constitutive or basal glucose uptake in the cells and can transport aldose, including pentose and hexose 1,15 .…”

The effects of cisplatin, an emetic agent, on behavior and plasma cortisol levels in goats

“…Each sample was immediately transferred to a polypropylene tube containing sodium heparin and stored in an ice bath. Within 60 min from the collection, plasma samples were separated by centrifugation (1400g, 4 C, 10 min) and stored at À30 C. The detailed procedure for the Cor assay was presented in our previous article (Aoyama et al, 2009). In brief, before the assay, Cor was extracted from the plasma with diethyl ether.…”

Respostas fisiológicas, produtivas e comportamentais de ovelhas Santa Inês submetidas a manejos considerados estressantes e desempenho de seus cordeiros

“…As ovelhas ganharam peso no período pós-parto em relação ao peso mensurado no parto, em ambas as lactações, não apresentando diferença entre os pesos das ovelhas ao parto e à desmama e pesos entre idades a desmama (P>0,05 O perfil das curvas de concentrações de cortisol com a imposição do estresse via administração de ACTH foi semelhante aos resultados de outros autores (TOERIEN et al, 1999;DELGADO, 2008;AOYAMA et al, 2009). Esse perfil clássico é avaliado para definir a capacidade de resposta ao estresse em diferentes espécies de ruminantes domésticos (FULKERSON;JAMIESON;NEGRÃO et al, 2004).…”