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Biomedical subjects

D Boucher

Publications and source records attributed to D Boucher.

At least 109 records · Page 6Linked to original sources
PubMed1980

[Developmental changes in plasma gonadotropins and testosterone and in testicular lutropin receptors in normal and cryptorchid rats].

Testis weight, ventral prostate weight, plasma gonadotropins and testosterone and testicular LH receptors were assessed throughout sexual maturation in the 23 to 84 day old rat. Intact, sham-operated and cryptorchid rats (operated at day 21) were studied. In the intact rats, plasma FSH rose to a peak at day 33, and fell to a plateau from day 50 throughout adult life. Plasma LH showed a sharp peak at day 42. Testis LH receptor content increased continually with age, reaching a plateau at day 49, but there was no change in the affinity constant (Ka = 2.4 +/- 0.5 X 10(10) M-1) measured at four time intervals. These observations suggested that the peak of FSH initiated an increase in testicular LH receptors, and that the LH peak enhanced it. In the cryptorchid rats, FSH showed a maximum between days 30 and 40. After day 33, FSH was higher in the cryptorchid rats than in the controls. The pattern of plasma LH was different in controls and cryptorchids; in the latter group, LH was often higher than in the controls. Testicular LH receptors increased continually between days 23 and 84, but Ka remained constant (Ka = 2.2 +/- 0.9 X 10(10) M-1) during that period. When compared with the control rats, the cryptorchid animals showed an increased concentration of testicular LH receptors at day 84, but this concentration decreased at days 35, 49 and 84; plasma testosterone also declined at days 23 and 49. These data suggested that the Leydig cell function of the cryptorchid rats was altered.

Animals↗
PubMed1978

[Blood prolactin in insulin-dependent diabetics. Basal study and effect of stimulation].

Blood prolactin levels were measured under basal conditions and following the intravenous injection of TRH at time 0, 30, 60 and 120 minutes in 22 men and 21 women insulin-dependent diabetics, aged less than 50 years and not taking any drug influencing prolactin secretion. Prolactin levels were significantly higher (alpha = 0.05) at the 120th minute in male diabetics and under basal conditions and at the 60th minute in female controls. There was no correlation with retinopathy, age and control of diabetes. At the 30th minute, prolactin levels were higher when diabetes was of more recent onset. These results confirm the absence of any participation of prolactin in the development of retinopathy, although variations in prolactin may be seen in association with the presence of diabetes.

Adult↗
PubMed1978

[Chronic vascular catheterization in the rat. Adaptation to injections and semi-continous blood sampling for hormonal studies].

A method for frequent sampling of blood and injections of fluids in undisturbed rats is described. The right external jugular vein and the left carotid artery are cannulated without completely blood stream interruption in the vessel. Injection or perfusion can be performed during several weeks. Blood was collected for at least 15 post-operative days. The technique appears suitable for pituitary kinetics studies which can be carried out several times in rats bearing indwelling catheters.

Acclimatization↗
PubMed1978

Circadian variations of ovarian ascorbic acid depletion in response to luteinising hormone in the rat.

The ovarian ascorbic acid (OAA) was titrated, three hours after an I.V. injection of either saline or LH, administered to 46 day-old Sprague Dawley female rats pretreated with P.M.S., H.C.G., and estradiol benzoate (and undecylate). The rats were killed at specific times along the 24-hour scale (L.D. 12:12; L 06(00) to 18(00); Ambient temperature 24 degrees C +/- 2 degrees C). The OAA content varied with a statistically significant circadian rhythm in the controls. The minimum dose of LH effecting OAA depletion varied systematically with the circadian system phase. OAA depletion increases with the dose of LH, and also depends on the circadian time that the animal is killed; it is maximum at the same time that the OAA peak is found in the controls. The slope of the linear regression (quantity of OAA as a function of the logarithm of the LH doses administered) is always significant, but varies over the 24-hour span; in consequence the LH biological titration must be carried out rapidly, the optimal circadian time for killing the animals is about 16(30).

Animals↗