Recently, bromocriptine has been successfully introduced as medical therapy for the pituitary hypersecreting syndromes of hyperprolactinemia and acromegaly. Subsequently, an inhibitory effect on ACTH secretion was reported using bromocriptine in Cushing's disease. While most studies have focused on the acute response to bromocriptine, few have investigated the response to chronic therapy with this agent. In this report, we describe a patient with Cushing's disease in whom an acute inhibition of ACTH and cortisol was demonstrated following bromocriptine and in whom the long term administration of bromocriptine as the sole therapy produced a transient beneficial response. Further pharmacologic testing suggested this inhibitory effect on the hypothalamic-pituitary-adrenal axis was mediated through dopaminergic stimulation.

Adrenocorticotropic Hormone↗

PubMedDate not supplied

Changes in thyrotropin-releasing hormone levels in alligator stomach during fasting.

Stomach tissue of the American alligator, Alligator mississippiensis, contains substantial levels of thyrotropin-releasing hormone (TRH) which behaves identically to the synthetic hormone on radioimmunoassay (RIA) and high performance liquid chromatography (HPLC). Fasting induces a marked increase in gastric tissue levels of this hypophysiotropic hormone, but is without effect on hypothalamic content, suggesting a physiological role for TRH in gastric function of this vertebrate.

Alligators and Crocodiles↗

PubMedDate not supplied

Partial purification and characterization of a novel growth hormone-releasing factor (GRF) from teleost brain related to the rat hypothalamic peptide.

A growth hormone-releasing factor (GRF)-like molecule has been partially purified and characterized from acid extracts of codfish (Gadhus morhua) brain using immunoaffinity and gel chromatography, followed by HPLC. This material has a mol.wt. which is similar to known mammalian forms of GRF but is immunologically and/or chromatographically distinct from previously described GRF peptides. However, it is related to rat(r) GRF(1-43) since it causes marked displacement in the rGRF RIA. Codfish GRF is a highly specific and potent hypophysiotropic factor as shown by its ability to stimulate the release of GH, but no other hormone, from rat anterior pituitary cells in vitro. These findings suggest that, phylogenetically, GRF is an ancient molecule with its biologic activity and certain immunoreactive domain(s) conserved, at least, from teleost to mammal.

Animals↗

PubMedDate not supplied

Transplantation of fetal growth hormone-releasing factor-immunoreactive neurons into the ventricular system of adult MSG-treated rats.

Fetal (17-18 days of gestation) mediobasal hypothalamic tissue (MBH) was transplanted into the third ventricle of adult, male rats which had been treated neonatally with monosodium glutamate (MSG). MSG treatment caused a marked reduction of growth hormone-releasing factor-like-immunoreactive (GRF-i) perikarya in the arcuate nucleus and GRF-i fibers in the median eminence (ME), as compared to littermate controls. When normal fetal MBH was transplanted into the third ventricle of MSG recipients, numerous GRF-i perikarya were located within the graft four weeks following surgery. GRF-i fibers in the ME of MSG-treated rats were enhanced when MBH grafts were in close contact with the ME, but not when transplants were located dorsally or rostrally in the third ventricle without making contact with the recipient's ME. Fetal cerebral cortex, which was grafted as a control tissue, did not contain GRF-i neurons. These immunohistochemical results suggest that grafted fetal GRF-i perikarya may contact the recipient's ME to increase the content of GRF previously depleted by exposure to MSG.

Animals↗

PubMedDate not supplied

[Characteristics of the effect of an excess of thyroid hormones in dogs].

Explore the source record for details and available documents.

17-Hydroxycorticosteroids↗

PubMedDate not supplied

Assessment of sex chromosome composition using fluorescent in situ hybridization as an adjunct to GTG-banding.

Fluorescent in situ hybridization (FISH) using dual color X chromosome- and Y chromosome-specific probes was employed to assess further the sex chromosome copy number in cells of a phenotypic female patient with hypergonadotropic hypogonadism, primary amenorrhea and growth retardation. The GTG-banding analysis of peripheral blood lymphocytes had revealed the presence of predominantly 46,XY cells. A FISH analysis, undertaken to assess further the contribution of a minor cell line, yielded frequencies of 87% cells with the 46,XY constitution and 9% with the 45,X constitution. To establish unequivocally the presence of mosaicism, a skin biopsy was obtained for fibroblast culture, which further corroborated the results of the peripheral blood study. Fluorescent in situ hybridization analysis revealed 74% of the cells to be 46,XY and 12% to be 45,X. The unequivocal presence of XY cells puts the patient at risk for neoplastic transformation of the gonads. Laparoscopy and surgical removal of the patient's presumptive streak gonads were therefore undertaken. Cytogenetic results derived from the gonadal tissues further strengthened findings of previous cytogenetic analyses. It is our experience that FISH is a useful adjunct to established cytogenetic techniques in the management and monitoring of patients similar to the proband described in this study.

Adolescent↗