The role of trace elements in male infertility.

The elemental status of seminal plasma collected from four populations subdivided on the basis of sperm counts is presented. Elemental analysis was performed by inductively coupled plasma-source mass spectrometry (ICP-MS) for calcium, cadmium, cobalt, chromium, copper, iron, magnesium, manganese, molybdenum, nickel, lead, rubidium, selenium, vanadium, and zinc. The majority of elements reflected no statistically significant differences among the four groups. The role of trace elements in infertility may be more directly related to sperm and whole semen than seminal plasma levels.

Studies on the control of gonadotrophin release in the gonadectomized male rat: evidence for a lack of involvement of the hypothalamic noradrenergic system in the long-term castrated rat.

The effects of castration with or without testosterone replacement in the adult male rat were studied to investigate possible hypothalamic mechanisms by which changes in gonadotrophin secretion occur at different times after castration, with particular reference to the continuing LH rise and its lack of suppression by testosterone in the long-term castrated rat. Castrated rats received either subcutaneous silicone elastomer implants containing testosterone or empty implants at the time of castration, and a sham-operated group served as controls. At 1, 10 and 40 days after castration, there were six-, 15- and 25-fold rises respectively in LH and 1.5-, two- and fivefold rises in FSH. However, there were no significant changes in hypothalamic noradrenaline concentration and turnover or in alpha-adrenoceptor density and affinity at any time after castration. Testosterone implants were effective in suppressing gonadotrophin release at 1 and 10 days, but not at 40 days after castration, and did not significantly affect hypothalamic noradrenaline turnover or alpha-adrenoceptors at any time. Neither acute inhibition of the noradrenergic system, using either the alpha-adrenoceptor blockers phenoxybenzamine and phentolamine or the synthesis inhibitor alpha-methyl-p-tyrosine, nor chronic depletion of hypothalamic noradrenaline by 6-hydroxydopamine had any significant effect on the normal rise in LH levels seen on days 10 and 40 after castration, and did not alter the ability of testosterone to suppress LH levels. This indicates that, in the long-term castrated rat, the noradrenergic system may not be involved in the control of gonadotrophin release. However, at 16 h after castration, alpha-adrenoceptor blockers and alpha-methyl-p-tyrosine did reduce LH levels, indicating that the noradrenergic system is likely to be involved in the short-term response to castration.

Physical changes associated with the onset of precocious puberty in rats after treatment with PMSG.

Body dimensions, composition, oxygen consumption and core temperature were measured in 2 groups of immature rats treated with PMSG. The first group weighed over 60 g on Day 27 of life and responded to PMSG treatment by ovulating; the second group weighed less than 60 g and did not ovulate after PMSG. Body composition, expressed as a percentage of body weight, was identical in the two groups, but growth rate, oxygen consumption and body temperature were all lower in the lighter animals. Oxygen consumption and body temperature were manipulated by altering temperature (i.e. 5, 22 and 30 degrees C) or by hyperphagia, and a positive correlation was found between body temperature and the occurrence of ovulation.

Plasma amine and hormone changes in 'post-partum blues'.

The relationship between hormone levels, plasma catecholamines, and mood disturbances has been investigated in 44 patients during days 2 to 5 of the immediate post-partum period. Fifty-two per cent of the mothers showed periods of emotional lability although there was no significant correlation between plasma concentrations of FSH, prolactin, oestrone, oestradiol, cortisol, or progesterone and the incidence of post-partum blues. In contrast there was a significant reduction of circulating catecholamines which correlated with mood disturbances. Women who experienced only a single day of post-partum blues had significantly lower levels of noradrenaline and adrenaline on that day compared with preceding or subsequent days.

The correlation between LH determination in the urine (Hi-Gonavis) and serum LH, FSH, oestradiol, progesterone, prolactin levels, and vaginal cytology at midcycle.

Radioimmunoassays (RIA) of serum gonadotrophins, prolactin, oestradiol, and progesterone were carried out from day 10 to 20 in 25 normal women for two cycles. In addition, we measured LH in urine twice daily using semiquantitative Hi-Gonavis kits. Finally, vaginal cytology was assessed daily in order to find out the optimum time for conception. LH in serum, as well as in urine, increased significantly at midcycle and so did FSH, prolactin, oestradiol, and the cornification index. Hi-Gonavis showed a significant increase 12 hours prior to the day of ovulation (day 0). The levels reached the peak on the day of ovulation and remained high 12 hours after the peak level on day 0. For the evaluation of the optimum time for conception in normal women who receive artificial insemination, or to improve fertility in those who have irregular ovulatory cycles, determination of the urinary LH by means of Hi-Gonavis appears to be useful, reliable, and economic, both in time and expense.

Investigation into the hypogonadism of the obese mouse (genotype ob/ob).

Features of the reproductive axis in the genetically hypogonadal, obese mouse (genotype, ob/ob) were examined at 5-8 months of age and compared with those of wild-type litter mates. Hypothalamic concentrations of dopamine and 5-hydroxytryptamine were normal. Those of 5-hydroxyindoleacetic acid, noradrenaline and LH-RH were raised. LH-RH was biologically active. Pituitary concentration of LH was normal, but that of FSH was raised. Serum concentrations of LH and FSH, compared with those of wild-type animals, were normal and low, respectively. Gonad and accessory sex organs weights were reduced. These findings suggest that the release of FSH but not LH is defective in the ob/ob mouse. Preliminary in-vitro experiments indicated that the pituitary gland responded normally or even supernormally towards LH-RH in its release of LH. The defect in the reproductive axis of the obese mouse may be due to inadequate release of LH-RH although an insensitivity of the pituitary gland towards LH-RH in its release of FSH cannot be excluded.

Blood pressure changes and cardiovascular lesions found in rats given T-2 toxin, a trichothecene secondary metabolite of certain Fusarium microfungi.

White weanling rats were given intragastrically 4 doses of T-2 toxin (3 alpha-hydroxy-4 beta-1,5-diacetoxy-8 alpha-(3-methylbutyryloxy)-12,13-epoxytrichothec-9-ene) a secondary metabolite of certain Fusarium species, 6 out of 9 treated rats developed increased blood pressure; these animals showed microscopically severe cardiovascular abnormalities. Occasional contamination of foodstuffs wh Fusarium may contribute to hypertension and cardiovascular lesions in animals and man.