The hypothalamic anterior pituitary system in the clinacteric age period

Hormonal treatments modulate pulsatile plasma growth hormone, gonadotrophin and osteocalcin levels in postmenopausal women

Oestrogen plays a role in modulating growth hormone (GH), luteinizing hormone (LH), follicle-stimulating hormone (FSH) and osteocalcin secretion in women. Indeed, the postmenopausal period is characterized by changes in plasma GH, LH, FSH and osteocalcin levels. The aim of the present study was to investigate the changes in the secretory patterns of these hormones in postmenopausal women under different therapeutic regimens. A total of 20 subjects took part in the study. They were subdivided into four groups comprising 5 untreated postmenopausal women (time since menopause 1-5 years), 5 postmenopausal women receiving steroid hormone replacement therapy, 5 postmenopausal women receiving salmon calcitonin and 5 fertile women with regular menstrual cycles. Blood samples were collected every 15 min for 4 h and hormone levels were measured by radioimmunoassay. Plasma GH levels fell in the postmenopausal women, but were restored under oestrogen-progestogen treatment. The pulsatile patterns of plasma LH and FSH did not show significant differences in the treated and untreated women. Plasma osteocalcin levels showed episodic fluctuations and mean levels decreased under steroid hormone or calcitonin treatment. No significant correlation was observed between plasma GH and osteocalcin or gonadotrophin levels or body mass index.

The menopausal hot flash: a procrustean bed of research

There are several scientific researchers from a variety of academic disciplines investigating the menopausal hot flash (MHF). Synthesis of all MHF research findings results in contradictory and inconclusive information available to health care providers and perimenopausal women. This study used epistemological construction and hermenuetical understanding to explore this information problem. Specific MHF exemplars, the problem-solutions, were constructed from extant scientific literature; two models of health guiding MHF research were generated from these exemplars. These models, health as a shared and communicable experience and health as a medical-physiological concept, provided a focus for hermeneutical understanding of the MHF information problem. Cooperative-collaborative inquiry was proposed as an approach for future MHF research.

Effect of pituitary gonadotrophins on proliferation of primary cultures of human ovarian stroma

Proliferation of ovarian stromal cells is a common phenomenon in peri- and post-menopausal ovaries. It is generally assumed to be secondary to the rise in circulating gonadotrophins at the menopause, though the process by which it occurs is poorly understood. This study aimed to examine the effect of menopausal levels of pituitary gonadotrophins on the growth of primary cultures of ovarian stroma. A culture system was developed using primary explants of ovarian stroma on a collagen substrate. The effect of follicle stimulating hormone (FSH; 10(-5) g/l) and luteinizing hormone (LH; 10(-5) g/l) on the proliferation of cultures derived from the cortices and medullae of ten ovaries was evaluated using a dual radiothymidine labelling technique. FSH was stimulatory to cortical cultures from 9/10 ovaries and medullary cultures from 7/10 ovaries, while LH was stimulatory to cortical cultures from 6/9 ovaries and medullary cultures from 5/10 ovaries. The responsiveness of the cultures did not correlate with the degree of hyperplasia in vivo. This study demonstrates that pituitary gonadotrophins may modulate the growth of stromal cells in culture, and thus may play a role in the process whereby stromal proliferation occurs in peri- and post-menopausal ovaries.

Effect of premenopausal castration and incremental dosages of conjugated equine estrogens on plasma follicle-stimulating hormone, luteinizing hormone, and estradiol

Plasma levels of follicle-stimulating hormone (FSH), luteinizing hormone (LH), and estradiol (E2) were measured serially in 11 premenopausal patients before and after hysterectomy with bilateral salpingo-oophorectomy. One week after operation an incremental dosage regimen of conjugated estrogens (CEE) in tablet form was commenced on a basis of two weeks with therapy (0.3, 0.625, 1.25, and finally 2.5 mg.), with each dose interspersed by two weeks without therapy. FSH, LH and E2 levels were measured at the end of each period with and without therapy. E2 levels fell within 24 hours of operation while FSH and LH levels rose gradually. CEE therapy produced an elevation of E2, but circulating concentrations comparable to the premenopausal values were only maintained during the dosage periods of 0.625 and 1.25 mg. of CEE. In only one instance did CEE succeed in reducing FSH to premenopausal levels, and that was at a dosage of 2.5 mg., in which instance the E2 level was higher than the premenopausal value. LH was never reduced to a premenopausal level. Thus, the data indicate that CEE alone in dosages up to 2.5 mg. per day was unable to reproduce in postmenopausal women the gonadotropin and E2 blood serum levels shown to exist prior to oophorectomy. Usual CEE treatment after menopause, therefore, in itself does not represent physiologic "hormone replacement therapy," if defined as the dosage required to maintain premenopausal circulating concentrations of reproductive hormones.