8 research outputs found
Effects of morphine on hypothalamic corticotropin-releasing factor (CRF), norepinephrine and dopamine in non-stressed and stressed rats.
The effects of morphine on the hypothalamic corticotropin-releasing factor (CRF), norepinephrine (NE) and dopamine (DA) concentrations were investigated in non-stressed and stressed rats. Acutely administered morphine stimulated both the synthesis and release of CRF in the hypothalamus, thereby activating the pituitary-adrenocortical system in non-stressed rats, but inhibited the stress-induced CRF synthesis and ACTH-corticosterone secretion. Either a morphine or ether-laparotomy stress reduced NE and DA concentrations in the hypothalamus. A pretreatment with morphine inhibited the stress-induced reduction in the hypothalamic NE and DA concentrations, and induced a significant increase in the DA concentration. These observations suggest that hypothalamic NE and DA are involved in morphine-induced changes in hypothalamo-pituitary-adrenocortical (HPA) activity and that endogenous opiates have a role in regulating CRF secretion by interacting with hypothalamic biogenic amines.</p
A case of non-Hodgkin's lymphoma associated with hypercalcemia.
A patient with a diffuse, small cleaved cell, non-Hodgkin's lymphoma associated with marked hypecalcemia was described. Antibody to the adult T-cell leukemia-lymphoma virus was absent. Although bone marrow was infiltrated by lymphoma cells, destructive or lytic bone lesions could not be detected. The serum level of immunoreactive parathyroid hormone C-terminal (PTH-C) was normal. The serum level of 1, 25-dihydroxyvitamin D was lower than normal. This case suggests that other humoral substances produced by lymphoma cells may be responsible for hypercalcemia.</P></p
Effect of Hyperosmotic Stimulation and Adrenalectomy on Vasopressin mRNA Levels in the Paraventricular and Supraoptic Nuclei of the Hypothalamus:
The effects of salt loading and adrenalectomy on arginine vasopressin (AVP) mRNA levels in the paraventricular nucleus (PVN) and the supraoptic nucleus (SON) of the hypothalamus were studied by semiquantitative in situ hybridization histochemistry, using a synthetic oligonucleotide probe and a computer-assisted image analysis system. Salt loading (2% NaCl) for 7 days produced marked increases in AVP mRNA levels in the magnocellular neurons of the PVN, SON, and accessory nuclei. Adrenalectomy caused an increase in AVP mRNA expression in the magnocellular part of the PVN and the expansion of hybridization signals into its medial parvocellular region, where the cell bodies of corticotropin-releasing hormone (CRH) neurons are located. No apparent alteration of AVP mRNA levels was observed in the SON following adrenalectomy. These results indicate that hyperosmotic stimulation and the loss of circulating glucocorticoids had differential effects on AVP gene expression in the PVN and SON, and that the magnocellular PVN and SON neurons responded in different manners to the loss of feedback signals.</p
Effect of a long-acting somatostatin analogue (SMS 201-995) on a growth hormone and thyroid stimulating hormone-producing pituitary tumor.
A 46-year-old woman with acromegaly and hyperthyroidism due to a pituitary adenoma. She had high serum thyroid-stimulating hormone (TSH) levels and very high serum growth hormone (GH) levels. Transsphenoidal removal of the tumor, post-operative irradiation, frontal craniotomy for removal of residual tumor and large-dose bromocriptine therapy were carried out consecutively. After therapy, serum GH levels gradually decreased, but not to the normal range, and serum TSH levels remained at inappropriately normal levels. Using immunoperoxidase techniques, GH-, TSH- and follicle-stimulating hormone (FSH)-containing cells were demonstrated in the adenoma. A long-acting somatostatin analogue (SMS 201-995, 600 micrograms/day) suppressed the serum GH level to the normal range with a concomitant suppression of TSH. Furthermore, the paradoxical serum GH responses to TRH and LH-RH were slightly improved. No important subjective side-effects were noted. Therefore, SMS 201-995 appeared to be a very effective drug in this patient with a GH- and TSH-producing pituitary tumor.</P></p