In 2 prepubertal bulls 10-min blood samples collected during a 24-h period showed that gonadotrophin and testosterone peaks occurred regularly at intervals of 6h in one animal and 8h in the other. There was a clear relationship between the LH, FSH and testosterone peaks. The increase of gonadotrophin levels was followed 20 +/- 6 (s.d.) min later by an increase of testosterone; the interval betw...

While it is now widely accepted that two gonadotrophins, resembling mammalian LH and FSH, are produced by the pituitaries of birds, reptiles and amphibians, most work with bony fishes suggests the presence of only one gonadotrophin in this class of vertebrates (e. g. Burzawa-G6rQrd, 1971 ; Donaldson et al., 1972 ; BurzawaG6rard et al.,1975 ; Breton et al., 1976). This conclusion is, however, be...

Ultrasound assessment of ovarian volume, follicular size, and uterine growth was undertaken in 40 normal premenarcheal girls aged 6 months to 14 years. Ovarian follicles were detected from 6 months of age and increased in size and number, so that after the age of 8.5 years there was a progressive increase in the incidence of 'megalocystic' appearance. Eight girls with idiopathic precocious pube...

Congenital hypogonadotrophic hypogonadism (CHH) is a rare form of infertility caused by deficient secretion or action of gonadotrophin-releasing hormone. There is no consensus regarding the optimal approach to fertility treatment in CHH men. In most cases, appropriate hormonal treatment with human chorionic gonadotrophin with or without follicle stimulating hormone will induce testicular develo...

Effective contraception is necessary in countries where limiting population growth has become a public policy imperative. The main antigenic targets for contraceptive vaccine development can be listed as following: 1) sperm antigens, 2) zona pellucida antigens, 3) gonadotrophin-releasing hormone, 4) chorionic gonadotrophin, 5) other protein/peptide hormones (follicle-stimulating hormone, lutein...

A case of successful pregnancy in an in-vitro fertilization cycle, in spite of an accidental exposure to daily long-acting gonadotrophin-releasing hormone analogue administration, is reported. The patient underwent two intracytoplasmic sperm injection cycles with thawed epididymal spermatozoa, in which, due to a pharmacist's mistake, ovarian stimulation was carried out by a combination of long-...

Ovulation Induction and Oocyte Recovery Ovarian hyperstimulation was achieved using GnRH analogue (nafarelin acetate, Synarel®, Pfizer) along with human recombinant FSH (r-hFSH: Gonal-F®, MerckSerono) in a long down-regulation protocol. Starting gonadotrophin dose varied from 150-300 IU and was based on female age, body mass index, ovarian volume, basal FSH levels and the number of preantral fo...

Familial cerebellar ataxia with hypogonadotrophic hypogonadism is a rare condition. Two affected siblings in a sibship of three were studied and found to have low plasma gonadotrophin levels. No rise in gonadotrophin levels was demonstrable after repeated stimulation with LHRH. The pattern of TSH and prolactin responses to TRH stimulation suggest hypothalamic dysfunction. The results clearly id...