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At least 487 records · Page 27Linked to original sources
PubMed1993

[Protective effect of panaxatriols on function of reproductive endocrine axis in radiation-injured rats].

After whole body irradiation with X-ray 5 Gy (radiation condition: 0.31 Gy.min-1, 200 kV, 10 mA, 0.5 mm Cu and 1.0 mm Al), the male rats were given ip panaxatriols 5 mg.d-1 24 h before and after irradiation for 14 d. The results showed that hypothalamic leu-enkephalin (165 +/- 12 vs 131 +/- 14 pg.mg-1), pituitary beta-endorphin (2.3 +/- 0.5 vs 1.6 +/- 0.3 ng.mg-1) contents, and serum testosterone (1.66 +/- 0.15 vs 0.82 +/- 0.23 ng.ml-1) level were decreased, while serum FSH (1.34 +/- 0.10 vs 1.99 +/- 0.10 ng.ml-1) level increased in irradiation group vs normal control. These indices approached to control levels in irradiation + panaxatriols group. These suggest that panaxatriols have protective effects on reproductive endocrine axis and promote their recovering course from the radiation injuries.

Animals↗
PubMed1994

Prospective study of pituitary-gonadal function to evaluate short-term effects of ablative chemotherapy or total body irradiation with autologous or allogenic marrow transplantation in post-menarcheal female patients.

Pituitary-gonadal (P-G) function was evaluated 0-3 months before and 3-4 months after bone marrow transplantation (BMT) in 15 post-menarcheal females aged 17-30 (21.6 +/- 0.34) years with haematological malignancies. All patients had evidence of gonadal insufficiency prior to BMT in that their basal and human menopausal gonadotrophin (HMG)-stimulated oestradiol (E2) levels were significantly lower than those of control subjects. The patients also had markedly higher basal FSH levels and exaggerated responses to 100 micrograms iv gonadotrophin release hormone bolus compared with those of control subjects. However, the conditioning regimens employed prior to BMT, i.e. cytotoxic chemotherapy (CT) and total body irradiation (TBI), acting either singly or in combination, caused further ovarian damage. As a result, their gonadotrophins rose further into the menopausal range. Their oestradiol secretion diminished and ovaries became almost unresponsive 3-4 months after BMT. Pelvic ultrasound undertaken in 5 patients before and after BMT demonstrated a reduction in ovarian size associated with follicular depletion. All patients developed menopausal symptoms and became amenorrhoeic during this period. Contrary to expectation, the hormonal changes occurring acutely were similar in patients undergoing radiation-based regimens and those conditioned with high-dose chemotherapy alone. Also, the severity of ovarian dysfunction appeared independent of age at transplantation, the nature of the conditioning-regimen or the type of transplant. Gonadotrophic, thyrotrophic, lactotrophic and adrenocorticotrophic secretions were unaffected. These data indicate that the ovary suffers an acute insult during short-term chemotherapy but the anterior pituitary gland retains its trophic hormone reserve and secretory capacity.

Adolescent↗
PubMed1995

Chemoprevention by dietary dehydroepiandrosterone against promotion/progression phase of radiation-induced mammary tumorigenesis in rats.

When pregnant rats received whole body irradiations with 260 cGy gamma-ray at day 20 of pregnancy, and were then implanted with a diethylstilbestrol (DES) pellet for an experimental period of 1 year under feeding of a control diet, a high incidence (96.2%) of mammary tumors was observed. Administration of dietary 0.6% dehydroepiandrosterone (DHEA) together with DES implantation significantly decreased the incidence (35.0%) of mammary tumors. The first appearance of palpable tumors in the DHEA-fed group was 4.5 months later than that in the control group. For clarification of the mechanism of the chemopreventive action, we measured hormone levels in the serum of DHEA-fed rats. In the DHEA diet rats, the concentration of estradiol-17 beta exceeded, by approximately 6-fold, that in the control rats, while the levels of progesterone and prolactin were decreased by 30 and 45%, respectively. Interestingly, DHEA feeding prevented DES-induced hypertrophy of pituitary glands and DES-induced high level of prolactin in pituitary glands detected by immunohistochemical studies, but stimulated the development of mammary glands more than that in control rats treated with DES alone. These findings suggest that DHEA has a potent preventive activity against the promotion/progression phase of radiation-induced mammary tumorigenesis. The mechanism of chemoprevention by change of endocrinological environment is discussed.

Animals↗
PubMed1985

[Endocrinological reactions following UV A whole body irradiation].

The basal secretion of proteo-hormones alpha-MSH and ACTH in plasma as well as the changes of the plasma concentrations following UV A-whole-body irradiation were investigated on 40 young male volunteers with different pigmentation levels (Caucasians: skin types I, II, III. Blacks: skin type VI). Significantly lower mean basic values of alpha-MSH and ACTH of light-haired persons in comparison with dark-haired and black persons (p less than 0,05) were demonstrated. We observed furthermore a significant increase of these proteo-hormones (alpha-MSH: skin type I: 26,7%, skin type II: 22,7%) in persons less pigmented within a short time after UV A whole-body irradiation in contrast to the more pigmented volunteers. These results prove a cutaneous peripheral sensor for UV A-rays, reacting with a different sensitivity depending on disposition and inducing endocrinological reactions. How this cutaneous-hypothalamic-pituitary stimulus mediation functions in detail is not completely revealed up to now. In what respect the present results, which can be explained as a consequence of evolutionary development, have a connection with the induction of melanoma remains to be seen.

Adrenocorticotropic Hormone↗
PubMedDate not supplied

[Hemodynamics and myocardial contractility in chromophobe adenoma of the pituitary gland after conservative, and surgical treatment].

Mechano- and polycardiographic methods were applied before and after the treatment to study the cardiovascular system in 35 patients suffering from chromophobic adenoma of the hypophysis. Both conservative treatment with the use of gamma irradiation and surgical removal of the tumour leads to normalization of hemodynamic parameters. Contractile capacity of the myocardium remained unchanged after gamma therapy and diminished after surgical treatment.

Adenoma, Chromophobe↗
PubMed1993

Doses to radiation sensitive organs and structures located outside the radiotherapeutic target volume for four treatment situations.

This study documents dosage to radiation sensitive organs/structures located outside the radiotherapeutic target volume for four treatment situations: (a) head and neck, (b) brain (pituitary and temporal lobe), (c) breast and (d) pelvis. Clinically relevant treatment fields were simulated on a tissue-equivalent anthropomorphic phantom and subsequently irradiated with Cobalt-60 gamma rays, 6- and 18-MV x-ray beams. Thermoluminescent dosimeters and diodes were used to measure absorbed dose. The head and neck treatment resulted in significant doses of radiation to the lens and thyroid gland. The total treatment lens dose (300-400 cGy) could be cataractogenic while measured thyroid doses (1000-8000 cGy) have the potential of causing chemical hypothyroidism, thyroid neoplasms, Graves' disease and hyperparathyroidism. Total treatment retinal (400-700cGy) and pituitary (460-1000 cGy) doses are below that considered capable of producing chronic disease. The pituitary treatment studied consisted of various size parallel opposed lateral and vertex fields (4 x 4 through 8 x 8 cm). The lens dose (40-200 cGy) with all field sizes is below those of clinical concern. Parotid doses (130-1200 cGy) and thyroid doses (350-600 cGy) are in a range where temporary xerostomia (parotid) and thyroid neoplasia development are a reasonable possibility. The retinal dose (4000 cGy) from the largest field size (8 x 8 cm2) is in the range where retinopathy has been reported. The left temporal lobe treatment also used parallel opposed lateral and vertex fields (7 x 7 and 10 x 10 cm). Doses to the pituitary gland (5200-6200 cGy), both parotids (200-6900 cGy), left lens (200-300 cGy) and left retina (1700-4500 cGy) are capable of causing significant future clinical problems. Right-sided structures received insignificant doses. Secondary malignancies could result from measured total treatment thyroid doses (670-980 cGy). Analysis of three breast/chest wall and regional nodal irradiation techniques demonstrated a 25-50% decrease in secondary lung dose with use of independent collimation compared to use of custom alloy blocking material. However, it is unlikely that a reduction in secondary dose of this magnitude would reduce the risk of treatment sequellae. In four-field "box" pelvic irradiation, secondary testes dose may result in temporary (clamshell shield) or permanent azoospermia, but is unlikely to impair androgen production.

Brain↗
PubMed1983

[Cushing's disease: do patients remain dependent upon substitution therapy following microsurgical exstirpation of hypophyseal adenomas?].

Data on 4 patients with Cushing's disease (2 microadenomas, 2 macroadenomas with chiasma syndromes) demonstrate that a few months after microsurgical extirpation of the pituitary adenoma (and, in macroadenomas, irradiation) the previously suppressed normal ACTH-producing cells recuperate and react adequately to stimulation. Because of the similar behaviour of the remainder of the gland, none of the 4 patients needed hormonal substitution and all were back at work full time about 1 year after the operation. This is in contrast to the obligatory need for corticoid substitution after bilateral epinephrectomy, and affords ground to consider pituitary microsurgery the treatment of choice in these patients.

Adenoma↗