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Biomedical subjects

B Dutourné

Publications and source records attributed to B Dutourné.

6 recordsLinked to original sources
PubMed1983

An endocrine and histophysiological study of the testicular annual cycle in the hedgehog (Erinaceus europaeus L.).

The histophysiology of the testis was studied all year round in adult male hedgehogs living in middle-western France. Variations in Leydig and Sertoli cell populations were correlated to plasma testosterone levels and compared to variations in seminiferous tubule diameter and germ cell production. During the last part of the hibernating period, in winter, Leydig cell parameters and plasma testosterone levels increased and reached maximum values in February, 1 month before the maximum development of seminiferous epithelium. The numerous large-sized Leydig cells in spring and summer corresponded to the maximum levels of plasma testosterone and maximum development of seminiferous tubules, spermatogenesis, and Sertoli cells. Regression occurred in August for Leydig cells and plasma testosterone levels, in September for seminiferous tubules and spermatogenesis. All the gonadal functions remained depressed from September to November. The relative frequency of the stages and duration of the seminiferous epithelium cycle were also studied. The same duration (10 days) was observed in hibernating animals in winter and active animals in spring.

Animals↗
PubMed1981

The reproductive cycle in the male hedgehog (Erinaceus europaeus L.): a study of endocrine and exocrine testicular functions.

Seasonal changes in testicular and accessory gland weights, histological testicular structures, fructose and citric acid concentrations in two accessory glands and plasma testosterone levels were determined in adult male hedgehogs living in middle western France. Testicular activity started in winter (from December to February) during the last part of the hibernation period. During this resumption period, testis weights as well as all the testicular structural features (Leydig cell volume; length, diameter and volume of seminiterous tubules) increased. These changes were correlated with similar variations in plasma testosterone concentrations and accessory gland features (weight, fructose and citric acid contents). However, maximal development of endocrine testicular function was reached about one month before the completion of spermatogenesis and the maximal development of androgen target organs. Testicular activity was high from February-March to August-September, according to the year. After the spring peak corresponding to the main breeding period, a decrease in testicular activity was always noted in May-June. The values of the testicular features then remained high or increased again and a second breeding period always occurred. Finally, involution began at the end of summer but the endocrine function of the testis decreased before the exocrine function. All the gonadal functions were depressed from September to November. Our results show that in middle western France, one of the southern-most countries characterized by a mild, temperate climate, the testis of Erinaceus europaeus L. is activated earlier and the breeding season lasts longer than in any of the other European countries cited in the literature.

Animals↗
PubMed1979

[Electromyographic study of uterine activity in the castrated red fox (Vulpes vulpes L.) treated with oestradiol and progesterone (author's transl)].

Effect of oestradiol and progesterone on the electromyographic activity (EMG) of the uterus is studied in 6 groups of 2 previously castrated vixens (A, B, C, D, E, F). The animals of gropu A are treated daily with intramuscular injections of oestradiol benzoate alone or oestradiol and progesterone together. These hormones are also given to the group F, oestradiol by a subcutaneous tablet and progesterone intramuscularly. The other females only receive a silastic implant of oestrogen (groups B, C, D, E). Electrical activity is daily recorded during the various treatments, in unanaesthetized animals, by means of platinum electrodes permanently implanted in the uterus. Plasma oestradiol concentrations in peripheral blood are determined in groups A and B. The results show that : 1. OEstradiol induces rhythmic EMG activity composed of bursts of action potentials (Fig. 2). It appears after a delay of 1 to 3 days following the beginning of treatment, except in the animals of group E, treated with a 25 mg oestradiol implant (6 days). Then, EMG activity gradually increases, and the frequency of bursts is at a maximum within 24 to 48 hours. Except in group E, it exceeds 30 per 10 minutes and the amplitude of potentials sometimes reachs 1 mV.

Action Potentials↗
PubMed1978

Oestrogen and progesterone concentrations in peripheral blood in pregnant red foxes (Vulpes vulpes).

Oestrogen levels were low during most of gestation, but there was a significant increase (P less than 0.05) in oestradiol concentrations at implantation. Early pregnancy was characterized by high levels of progesterone which decreased significantly (P less than 0.001) thereafter, but there was no decline in progesterone or rise in oestrogen levels at parturition. There was no difference in the length of progesterone secretion between pregnant and non-pregnant females.

Animals↗
PubMed1977

Implantable telemetry system for long-term EMG.

Our aim was to record the uterine muscular activity of the badger or the fox. For long-term physiological experiments, commercial transmitters cannot be used. The operating time of commercial transmitters with a single set of batteries does not exceed 15 days at the most. In addition, the dimensions render implantation of such equipment impossible. It is not always necessary to record permanently but sometimes a few minutes a day are sufficient to assess the evolution of a phenomenon. We have conceived and constructed a miniature implantable receiver module which allows the transmitter to be switched on and off in order to be operated only during selected periods of time.

Animals↗