THE EFFECT OF ADRENALECTOMY, ADRENAL CORTICAL HORMONES, AND TESTOSTERONE PROPIONATE PLUS ADRENAL CORTICAL EXTRACT ON THE "ALKALINE" AND "ACID" PHOSPHATASES OF THE LIVER AND KIDNEY OF THE RAT

The regulatory mechanisms involved in the control of the nuclear NADPH-dependent 3-ketosteroid 5α-reductase (5α-reductase) activity were studied in liver, kidney and prostate. The substrate used was [1,2-3H]androst-4-ene-3,17-dione (androstenedione) (for liver and kidney) or [4-14C]androstenedione (for prostate). The hepatic nuclear 5α-reductase activity was greater in female than in male rats, was greater in adult than in prepubertal female rats, increased after castration of male rats, but was not affected by treatment with testosterone propionate or oestradiol benzoate. These regulatory characteristics are in part different from those previously described for the hepatic microsomal 5α-reductase. The renal nuclear metabolism of androstenedione, i.e. 5α reduction and 17β-hydroxy steroid reduction, was relatively unaffected by sex, age, castration and treatment with testosterone propionate. However, treatment of castrated male rats with oestradiol benzoate led to a significant increase in the 5α-reductase activity and a significant decrease in the 17β-hydroxy steroid reductase activity. Finally, the nuclear 5α-reductase activity in prostate was androgen-dependent, decreasing after castration and increasing after treatment with testosterone propionate. In conclusion, the nuclear 5α-reductase activities in liver, kidney and prostate seem to be under the control of distinctly different regulatory mechanisms. The hypothesis is presented that whereas the prostatic nuclear 5α-reductase participates in the formation of a physiologically active androgen, 5α-dihydrotestosterone, this may not be the true function of the nuclear 5α-reductase in liver and kidney. These enzymes might rather serve to protect the androgen target sites in the chromatin from active androgens (e.g. testosterone) by transforming them into less active androgens (e.g. 5α-androstane-3,17-dione and/or 5α-dihydrotestosterone).

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The ultrastructure and histochemistry of the cyst wall of Bucephalus haimeanus (Lacaze-Duthiers, 1854)

Parasitology ◽

10.1017/s0031182000062351 ◽

1977 ◽

Vol 75 (2) ◽

pp. 207-214 ◽

Cited By ~ 10

Author(s):

Jacqueline C. Higgins ◽

D. E. Wright ◽

R. A. Matthews

Keyword(s):

Cyst Wall ◽

Protein Complexes ◽

Middle Layer ◽

Outer Edge ◽

Acid Phosphatases ◽

Free Aldehyde ◽

Aldehyde Groups ◽

And Function ◽

Cyst Cavity ◽

Alkaline And Acid Phosphatases

Metacercarial cysts of Bucephalus haimeanus occur throughout the liver of Pomatoschistus microps, greater concentrations being found around the gall bladder, blood vessels and periphery of the liver. The cyst wall is composed of three layers, an inner granular, middle vacuolated and outer nucleated layer. The inner layer consists of three zones, an inner zone of irregularly compacted, granular material; a middle densely compacted zone and an outer moderately compacted zone. Vacuoles of the middle layer vary in appearance and appear to be discharging their contents into the cyst cavity. The cells of the outer layer are flattened and elongated with elongate nuclei but no other distinct organelles. Occasionally at the outer edge of the cyst are electron-dense cells which are in the process of degeneration. Only small amounts of collagen and very few leucocytes are associated with the cysts.The cyst wall is carbohydrate in nature containing some free aldehyde groups, galactogen and neutral mucosubstances. The inner layer appears to consist of mainly acidic mucopolysubstances and weakly acidic sulphomucins. Large amounts of protein, carbohydrate-protein complexes and DNA are also present within the cyst wall. Alkaline and acid phosphatases, ATPase, β-glucuronidase and N-acetyl-β-glucosaminidase were detected. The origin and function of the cyst wall is discussed.

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Synergism of testosterone propionate with growth hormone in promoting growth of hypophysectomized rats: effect of sexual differentiation

Journal of Endocrinology ◽

10.1677/joe.0.1270249 ◽

1990 ◽

Vol 127 (2) ◽

pp. 249-256 ◽

Cited By ~ 5

Author(s):

J. Klindt ◽

J. J. Ford ◽

G. J. Macdonald

Keyword(s):

Sexual Differentiation ◽

Testosterone Propionate ◽

Initial Study ◽

Male Rats ◽

Growth Enhancement ◽

Growth Responses ◽

Liver And Kidney ◽

Hypophysectomized Rats ◽

Synergistic Response ◽

Rates Of Growth

ABSTRACT The effect of testosterone propionate (TP), alone and in combination with porcine GH, on the growth of hypophysectomized rats was investigated. An initial study determined doses of TP and GH which would result in a synergistic response. Hypophysectomized male rats, approximately 40 days of age, received GH at doses of 5, 25 and 62·5 μg/day administered in two injections/day at 08.00 and 16.00 h. At all doses of GH, administration of TP at 100 μg/day significantly enhanced the GH-stimulated rate of growth. This growth enhancement by TP was greatest in combination with GH at 25 μg/day. In a subsequent study, growth responses to 25 μg GH/day and 100 μg TP/day were examined in animals with differing degrees of sexual differentiation. Sex groups were: intact males, males castrated at 11 days of age and females administered 100 μg TP at 3 days of age (masculinized rats), and males castrated at 2 days of age and normal females (non-masculinized rats). In all sex groups, growth of hypophysectomized rats was stimulated by GH. Genetic sex and masculinization did not influence the response to GH. Masculinized hypophysectomized rats exhibited significantly greater rates of growth and final live, empty body, liver and kidney weights than non-masculinized hypophysectomized rats. All sex groups other than normal females responded synergistically to the combination treatment of GH plus TP. Rats that experienced neonatal exposure to testosterone became programmed to respond to testosterone and demonstrated greater rates of growth and body and organ weights when administered the combination of GH plus TP. These data indicate that TP synergizes with GH to promote growth of hypophysectomized rats appropriately programmed to respond. The ability to manifest a synergistic response is a differentiated trait dependent upon exposure to testosterone during the appropriate period of development. The time of differentiation of this ability to respond to testosterone occurs earlier than that for differentiation of body growth. Journal of Endocrinology (1990) 127, 249–256

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