Morphometric studies on rat epididymis in the course of postnatal development (computerised image analysis).

The studies were aimed at histological and morphometric analysis of postnatal development of epididymis in rats aged 1, 5, 10, 20, 28, 35, 45 and 59 days. Diameter of ductuli efferentes and of ductus epididymidis, height of epithelium, section area fractions occupied by the epithelium and by the sublayer were estimated (using MultiScan software) and serum testosterone levels were measured. The results documented a stepwise development of the epididymis, in three distinguishable stages.

Long-term effect of neonatal monosodium glutamate (MSG) treatment on reproductive system of the female rat.

The study aimed at determining effects of monosodium glutamate (MSG), introduced in the perinatal period, on the reproductive system of sexually mature female rats. In days 2, 4, 6, 8, 10 the newborns received s.c. injections of MSG (4 mg/g body weight) or 2% NaCl solution. When the animals reached the age of 6, 12 or 18 months, their ovaries and uteri were isolated for histological and morphometric studies while in their sera estradiol level was estimated by the RIA technique. The perinatal injection of MSG was found to decrease relative weights of ovaries and uteri. In the ovaries increased numbers of primordial follicles and decreased numbers of graafian follicles were detected. Also the thickness of endometrium and of the epithelium, which lined the endometrium, were lowered in females, which received perinatal injections of MSG, as compared to the controls. Serum estradiol level in MSG injected females was lowered at the age of 12 and 18 months. In 12 and 18 month old females the alterations were accompanied by obesity and a decreased body length.

Morphometric studies on the testes of rats treated neonatally with oestrogen and subsequently with gonadotrophins and testosterone.

The experiments involved male rats, which were given a single subcutaneous dose of 1 mg stilboestrol on the first day of life. Beginning on day 28, subgroups of the rats received either gonadotrophins or testosterone for 39 days. The weight of the testes, serum luteinizing hormone and testosterone levels were determined while sections of the testes were subjected to morphological analysis and morphometric measurements, based on computerized techniques. The results demonstrated that a single dose of oestrogen caused a reduction in the cross-sectional area of the seminiferous tubules and a reduction in the thickness of the seminiferous epithelium, accompanied by inhibition of spermatogenesis. The number of and area occupied by Leydig cells, as well as the size of their cell nuclei, were also diminished, and the levels of serum testosterone decreased by 73%. All the experimental animals manifested significantly increased serum luteinizing hormone levels. Stimulation with gonadotrophins markedly increased the number of Leydig cells, their size and the size of their cell nuclei. This was associated with significantly increased levels of serum testosterone. Under these conditions, the cross-sectional area of the seminiferous tubules and the thickness of seminiferous epithelium remained less than those in the untreated controls. Following stimulation with testosterone the pattern of the seminiferous tubules resembled that noted after stimulation with gonadotrophins; the number of Leydig cells was markedly reduced but the size of both the cells themselves and of their nuclei approached normal values.

Effects of melatonin, testosterone and the two hormones administered in parallel on epididymis of the rat estrogenized with stilbestrol in the first day of life.

Effect of melatonin, testosterone and of both hormones given in parallel on rat epididymis was tested in rats given a single dose of 1 mg stilbestrol on the first day of the life. The hormones were given daily for 39 days, beginning from the 20th or 28th day of life. The single dose of estrogen treatment resulted in epididymis atrophy, accompanied by changes in glandular epithelium and in its stroma, when the rats reached mature age (59 or 67 days of life). In such rats, LH gonadotropin level was elevated and testosterone level was decreased. Administration of melatonin failed to affect the changes induced by estrogen treatment. Administration of testosterone alone or of testosterone in parallel with melatonin caused the epididymis status to resemble more closely that seen in control animals. Efferent ductules of the testis (head of epididymis) were also demonstrated to be more sensitive to the performed experimental procedures than the duct of the epididymis (body and tail of the epididymis).

Effects of melatonin, testosterone and the two hormones administered in parallel on ventral prostate of the rat treated with stilbestrol in the first day of life.

Effects of melatonin, testosterone and the two hormones administered in parallel on ventral prostate were examined in the rats treated with estrogens in the first day of life. Thirty-nine-day long hormonal stimulation with melatonin, testosterone or the two hormones in parallel was started in rats aged 20, 28, 35 or 45 days. A single dose of estrogens led to atrophy of ventral prostate when the animals reached maturity, which was associated with high LH levels and low testosterone levels in the serum. Melatonin accentuated estrogen-induced changes in prostate morphology of ventral prostate while initemporal administration of melatonin and testosterone led to a resultant effect of testosterone-induced stimulation and melatonin-induced inhibition.

Effect of estrogenization in the first day of life on the reproductive system in male rats.

The aim of the present report was to investigate dynamics of morphological and functional changes in the reproductive system of male rats between 20th and 84th day of life, injected neonatally with a single dose of stilbestrol. Marked reduction in relative weights of testes and accessory sexual glands was demonstrated in various periods of life. This was associated with inhibition of spermatogenesis at the stage of primary spermatocytes and with morphological as well as functional alterations in epididymis, seminal vesicles and ventral prostate. In the serum, high levels of LH and lowered testosterone levels were demonstrated.

[Effect of perinatal administration of monosodium glutamate (MSG) on the reproductive system of the male rat]. / Wplyw okolourodzeniowego wprowadzania glutaminianu sodu (MSG) na uklad reprodukcyjny szczura samca.

The study was aimed at investigating the effect of monosodium glutamate administered during the perinatal period on the reproductive system of sexually mature male rats. Monosodium glutamate (at a dose of 4 mg/g of body weight) or hypertonic saline was administered subcutaneously to newborn rats at 2--nd, 4-th, 6-th, 8-th and 10-th day of life. At the age of four months the rats were killed and histological and morphometric examinations of testes, epididymis, seminal vesicles and ventral prostate were carried out. Blood serum levels of LH, FSH, testosterone and 17-beta-estradiol were determined by radioimmunoassay. The administration of monosodium glutamate caused inhibition of growth, obesity and decrease in weight of pituitary glands and testes. Blood serum levels of and FSH as well as the height of epithelial cells of accessory sexual glands remained unchanged, whereas testosterone level was lowered.

Effect of melatonin on reproductive system in male rat, treated with estrogen in the first day of life.

The study aimed at demonstrating the possible stimulating or inhibitory effect of melatonin on reproductive system of male rats, the function of which was altered by single diethylstilbestrol dose introduced in the first day of life. The single estrogen dose in the first day of life induced in the studied rats, after they reached the adult age, inhibition of spermatogenesis as well as morphological and functional alterations in accessory sexual glands. This was associated with high level of LH gonadotrophin and with lowered testosterone level in the serum. Additional administration of melatonin between 45th and 84th day of life accentuated the above described changes induced by the single estrogen injection. Results of the studies demonstrated that melatonin in the experimental model not only failed to stimulate but provided an additional inhibitory effect on reproductive system in male rat.

Reproductive functions in the adult male rats after prolonged intraventricular administration of corticotropin-releasing factor (CRF).

The effect of intraventricular injection of synthetic oCRF on reproductive functions in the male rats were studied and changes were compared with intact and control rats (daily intraventricular injections of 10 microliter of 0.1% albumin solution in PBS). The long-term administration of oCRF into lateral ventricle of freely moving rats caused a significant increase in relative weights of adrenals, pituitary glands and a decrease in body weight. Plasma LH and testosterone levels were significantly depressed after 8 days of oCRF administration, while there were no alteration in studied parameters in the control rats. Control i.v.c. injections of 0.1% albumin solution in PBS were without effect on levels of any of the hormones or weights of testes, epidydimis, seminal vesicles and prostate. Obtained results indicate a central inhibitory action of oCRF on LH and subsequent testosterone release.