Effects of cysteamine on pituitary, MTTW15 tumor, and serum prolactin levels measured by rat lymphoma cell bioassay and radioimmunoassay

Journal Article · Tue May 01 04:00:00 EDT 1984 · Endocrinology; (United States)

OSTI ID:6781616

Parsons, J A; Peterson, E K; Hartfel, M A

Cysteamine (CSH), a sulfhydryl compound, reduces both serum and anterior pituitary (AP) PRL measured by RIA. We have used the Nb2 lymphoma cell bioassay (BIO) for PRL to evaluate possible CSH-related changes in PRL levels in sera and tissues of male and MtTW15 mammosomatotropic tumor-bearing female rats. Experimental animals received a single sc injection of CSH (300 mg/kg), and samples were collected 0.5-24 h later. Since CSH and serum from CSH rats were toxic in BIO, samples were dialyzed before assay. All samples were evaluated for PRL and GH by RIA as well. A significant decrease (P less than 0.05) in BIO serum PRL was evident in male rats 0.5 h after CSH; levels remained low for 24 h. Serum PRL by RIA was significantly depressed at 4 h but not at 0.5 h or 24 h. PRL in AP extracts was decreased (60-90%) at all times by BIO and RIA. Significant decreases of BIO- and RIA-detectable PRL were recorded in serum and tissues (AP and tumors) at 4 h in tumor rats. Sequentially bled (0.5-4 h) CSH-treated tumor-bearing rats showed 50% and 80% reductions in serum PRL at 1 and 4 h by both BIO and RIA. CSH had no effect on GH levels in sera and tissues of any animal studied at any time interval. Our results substantiate earlier reports on CSH-induced decreases in RIA-detectable PRL. They show that such changes cannot be attributed to assay effects alone, as significant decreases in circulating and stored PRL (both AP and tumor) were evident by BIO. Results with tissue extracts were the most dramatic. They suggest an action of CSH or a metabolic intermediate with stored PRL which reduces both extractable PRL and hormone release. Such an effect of CSH on PRL extraction has been suggested by others. Whatever the mechanism, it appears to be relatively specific, since GH cells were not affected.

• Research Organization: Department of Anatomy, University of Minnesota, Minneapolis
• OSTI ID: 6781616
• Journal Information: Endocrinology; (United States), Journal Name: Endocrinology; (United States) Vol. 114:5; ISSN ENDOA
• Country of Publication: United States
• Language: English

Related Subjects

550501 -- Metabolism-- Tracer Techniques
560305* -- Chemicals Metabolism & Toxicology-- Vertebrates-- (-1987)
59 BASIC BIOLOGICAL SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
AMINES
ANIMALS
BIOASSAY
BIOLOGICAL EFFECTS
BLOOD SERUM
BODY
DRUGS
ENDOCRINE GLANDS
GLANDS
GONADOTROPINS
HORMONES
ISOTOPE APPLICATIONS
LTH
MAMMALS
MAMMARY GLANDS
MEA
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
ORGANS
PEPTIDE HORMONES
PITUITARY GLAND
PITUITARY HORMONES
RADIOASSAY
RADIOIMMUNOASSAY
RADIOPROTECTIVE SUBSTANCES
RATS
RODENTS
THIOLS
TRACER TECHNIQUES
VERTEBRATES