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J Y Daniel

Publications and source records attributed to J Y Daniel.

At least 37 records · Page 2Linked to original sources
PubMed1986

Ultrastructural changes in the uropygial gland of the male Japanese quail, Coturnix coturnix, after testosterone treatment. Comparison with the sebaceous gland of the male rat.

The ultrastructure of the uropygial gland of the male quail was compared to that of the sebaceous gland of the male rat after castration and testosterone treatment of both species. In intact animals, the differentiating cells of these glands displayed almost the same pattern as regards their smooth endoplasmic reticulum, an organelle involved in lipogenesis in both cases. Castration reduced the volume of this organelle, while testosterone administration restored cell morphology to a normal or supranormal level. Finally, this study showed that at ultrastructural level, there is a close functional analogy between the uropygial gland of quail and the sebaceous glands of rats as regards their androgen dependency. Consequently, the uropygial gland might be an attractive model for study of action of androgens on sebaceous-like glands.

Animals↗
PubMed1986

Testosterone regulation of androgen receptor levels in the uropygial gland of quails (Coturnix coturnix): a further proof for the androgen dependency of the uropygial gland.

In castrated quails supplemented with testosterone by a chronically implanted silastic capsule, removal of the implant resulted in the gradual disappearance of the androgen receptors in both cloacal and uropygial glands. However, after a 7-day time span, the receptors reappeared in both glands but did not reach the original level of implanted birds. On the other hand, the photostimulation of intact birds induced an increase of the receptor content of their uropygial and cloacal glands when compared to sexually quiescent birds. These results show that, the concentration of the androgen receptors of the uropygial and cloacal glands of adult male quails is partly controlled by testosterone. By comparison with the mechanism of the action of testosterone in mammal target organs, our results add weight to the androgen dependency of quails uropygial glands (a sebaceous like organ).

Animals↗
PubMed1986

Acetaldehyde adducts with serum proteins: effect on diazepam and phenytoin binding.

The in vitro effects of acetaldehyde treatment on the binding of phenytoin and diazepam to human serum albumin (HSA) and human serum proteins (HSP) have been investigated. The incorporation of acetaldehyde into proteins following incubation with different concentrations of [1,2-14 C]-acetaldehyde (0.5, 25, 100 mmol/l) was carried out. The proteins were then dialyzed so that only the stable adduct was retained. Binding of phenytoin and diazepam was then studied. Scatchard plot analysis showed a slight decrease (p less than 0.01 for HSP and 25 mmol/l acetaldehyde) in the number of binding sites for phenytoin when the acetaldehyde/protein ratio was increased. The affinity constant was also increased (p less than 0.01) with 100 mmol/l acetaldehyde. No change could be demonstrated in the number of diazepam binding sites on HSA; an increase in the binding capacity of HSP was shown following incubation with 25 mmol/l acetaldehyde. The fraction of drug bound at therapeutic levels has been also calculated for both drugs. An increase for diazepam but no change for phenytoin can be observed before or after treatment of proteins with acetaldehyde.

Acetaldehyde↗
PubMed1986

Androgen regulation of the androgen receptor of the quail uropygial gland: application of a [3H]mibolerone exchange assay.

An exchange assay for androgen receptors in the quail uropygial gland using [3H]mibolerone was established. The most efficient exchange conditions were 3 days of incubation at 15 degrees C. Under these conditions, androgen receptors were stable in the presence of sodium molybdate, and the exchange of [3H]mibolerone with endogenous testosterone bound to cytosolic or nuclear androgen receptors was maximal. Less than 5% of [3H]mibolerone-binding sites occurred in the extracted nuclear pellets. Using this exchange technique, it was shown that androgen receptors in the uropygial gland of photostimulated male quail or castrated quail treated with testosterone were activated and that their concentrations in both cytosolic and nuclear fractions were increased. These results confirm the androgen dependency of the quail uropygial gland, and show that it is an organ which can be used as a model for the study of androgen action in sebaceous glands.

Animals↗
PubMed1985

Testosterone metabolism in the uropygial gland of the quail.

The metabolism of testosterone in the uropygial gland of the quail principally results in the production of 17 alpha, 5 beta derivatives. Moreover, an unusually small amount of testosterone is converted to 5 alpha-dihydrotestosterone. These results question the role played by intracellular 5 alpha-reduction in the response of the gland to testosterone stimulation.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗
PubMed1984

Androgen control of the secretion in the sebaceous-like preen gland.

Uropygial gland of quails was previously proved to have androgen receptors. The waxes secreted by this gland were shown to consist mainly of linear saturated fatty acids esterified by linear saturated diols. In adult male quails, the relative concentration of the C12 diol was found to be correlated to the androgen levels of the birds. Furthermore, in castrated quails implanted with testosterone propionate capsules, 6 days were required for the C12 diol to reach the level found in sexually active birds. These testosterone effects related to the C12 diol were nullified by cyproterone acetate administration. Consequently the C12 diol is a reliable specific marker for androgenicity in the quails' preen gland, a new and accurate model for the study of androgen action in sebaceous glands.

Animals↗
PubMed1984

Absence of 5 alpha-dihydrotestosterone action in the sebaceous-like uropygial gland of the male Japanese quail.

The uropygial gland of the quail, a sebaceous-like gland, has been proven to be androgen-dependent. Waxes secreted by this gland consist of fatty acids esterified by alkane-2,3-diols [12]. In castrated quails, the relative concentration of dodecane diol was enhanced after testosterone treatment; but 5 alpha-DHT could not evoke any increase in the relative concentration of dodecane diol. It is not possible from our present results to know if this lack of gland response to DHT administration is related to a high level of DHT metabolism in the gland cells or to a decreased affinity of the androgen receptor for DHT. However, because of the high similarity existing between uropygial gland of birds and mammalian sebaceous glands, these results give rise to the question of the true role of DHT in mammalian sebaceous glands.

Animals↗
PubMed1984

Androgen control of transcortin binding capacity in adult male ducks.

In adult male ducks submitted to marked variations in plasma testosterone concentration, plasma transcortin (CBG) levels were shown to be closely related to the level of plasma testosterone. In connection with previous data on female ducks, the results strongly support the evidence that at least in this species, CBG is under a stimulatory control by testosterone.

Animals↗
PubMed1984

Androgen regulation of secretions in the sebaceous-like uropygial gland of the male Japanese quail.

The uropygial gland of the male quail is a sebaceous-like, androgen-dependent structure. The waxes secreted by this gland consist of fatty acids esterified by alkane-2,3-diols. In adult male quail the relative concentrations of all fatty acids were not affected by castration and testosterone treatment; but in contrast, the relative concentration of dodecane diol was found to be correlated with the androgen levels. In castrated quail administration of testosterone induced an increase in the dodecane diol percentage which was blocked by protein-synthesis inhibitors. Furthermore, the effects of testosterone were found to be neutralized by the administration of cyproterone acetate. Consequently it may be stated that the relative concentration of dodecane diol is indeed a very good marker for androgenicity in the uropygial gland of the male quail. This experimental model seems well suited for evaluating the stimulators and inhibitors of the activity of the sebaceous gland.

Animals↗
PubMed1983

Testosterone stimulation of DNA-dependent DNA polymerase activities in the cloacal and uropygial glands of the male quail (Coturnix coturnix japonica).

DNA polymerase alpha and beta activities were studied and compared in the cloacal gland and the uropygial gland (sebaceous-like gland) taken from castrated quails after testosterone administration. In the cloacal gland, testosterone induced an important increase in DNA polymerase alpha while DNA polymerase beta was not found to be altered. In the uropygial gland, testosterone induced a cyclic variation of DNA polymerase alpha activity which may relate to the holocrine function of this gland.

Animals↗
PubMed1983

[25-hydroxyvitamin D plasma levels in adults, neonates and their mothers].

25-hydroxyvitamin D (25 OH vit D) plasma levels were measured according to the method of Preece et al. in 2 groups of subjects. Group 1 consisted of 10 adult controls in whom 25 OH vit D levels were measured 11 times at 1 month intervals. Group 2 consisted of 93 mother-child pairs including 71 neonates with normal plasma calcium levels (group 2a) and 22 with hypocalcemia (group 2b). In mothers, 25 OH vit D levels (group 2a: 12 ng/ml +/- 6.4 SD, n = 71; group 2b: 9.5 ng/ml +/- 3.5 SD, n = 22) were lower than in controls (25.1 ng/ml +/- 7.9 SD). In neonates, 25 OH vit D levels were correlated with those of their mothers; however there was no significant difference in neonates with or without hypocalcemia (group 2a: means = 11.9 ng/ml +/- 6.1 SD, n = 71; group 2b: means = 10 ng/ml +/- 4.1 SD, n = 22). 25 OH vit D levels in adults of group 1 were significantly correlated with exposure to sunlight, while no significant correlation was found in the mothers-children pairs of group 2. These results confirm the relationship of 25 OH vit D plasma levels of neonates with their mothers' but do not support the concept of a relation between low plasma levels in mother and the occurrence of hypocalcemia in neonates.

Adolescent↗
PubMed1982

[Evidence and characterization of an androgen receptor in the uropygial gland of the adult male quail].

5 alpha-DHT is bound with a high affinity (Kd = 0.8 nM) and a limited capacity (80 fmol/mg proteins) in the cytosol of the preen gland of quails, an analogue of sebaceous glands. The complex can be precipitated by protamin-sulfate and is sedimented in the 8 S region after ultra-centrifugation in a sucrose gradient. The occurrence of this binding that exhibits the main properties of an androgen receptor, supports the use of the preen gland of quails as a tool for the study of the mechanism of action of androgens in birds and as a model for the study of the androgen control of sebaceous-like glands.

Animals↗
PubMed1982

Interrelations between binding affinity and metabolic clearance rate for the main corticosteroids in the rabbit.

In the rabbit, the metabolic clearance rate (MCR) was found to be higher for corticosterone than for cortisol. At the same time corticosterone, aldosterone and 11-dehydrocorticosterone showed similar MCR while cortisone ranged at intermediate levels between cortisol and corticosterone. The relative binding affinity of transcortin to the corticosteroids, as calculated by an in vitro technique, decreased progressively from cortisol, to cortisone, then to corticosterone, then 11-dehydrocorticosterone and, finally to aldosterone. The occurrence of antibodies in plasma, induced against aldosterone, corticosterone or even cortisone resulted in a marked decrease in the MCR of the corresponding steroid, to the level measured in controls for cortisol. We deduced that, in rabbits: (1) the MCR of a corticosteroid is clearly connected with its binding to a specific protein; (2) in spite of the relatively high binding affinity of transcortin for corticosterone as compared to other species it nevertheless appears unable to significantly protect the steroid against peripheral metabolism; (3) a very effective protection is however, induced, by raising a specific antibody with a high binding affinity for corticosterone.

Adrenal Cortex Hormones↗
PubMed1981

Evidence of a sex related difference of transcortin level in adult ducks.

Corticosteroid binding globulin (CBG) serum level as evaluated by either equilibrium dialysis or gel filtration was found to be higher in male than in female adult ducks during the reproductive period. Castration did not modify CBG concentrations in females, whereas in males it induced a significant decreased in CBG, to the level observed in intact or castrated females. Testosterone injections administrated to castrated females increased CBG to the level of adult intact males. Finally it was found that testosterone stimulated CBG production in ducks without altering thyroxine levels.

Animals↗