Augmented transport and metabolism of sex steroids in lymphoid neoplasia in the rat

Journal Article · Sun Mar 01 04:00:00 EST 1987 · Endocrinology; (United States)

DOI:https://doi.org/10.1210/endo-120-3-1000· OSTI ID:6647478

Cefalu, W T; Pardridge, W M

Sex steroid hormones have been shown to influence a number of biological properties of lymphoid neoplastic tissue. Receptor occupancy is a function of the pool size of cellular exchangeable hormone therefore it is important to understand the mechanisms regulating hormone transport from the microcirculation and hormone metabolism. In this study, steroid hormone transport and metabolism were investigated in control and neoplastic lymph nodes after transplanting control rats with the WR-6 leukemic line. Steroid hormone transport and metabolism were studied after pulse labeling the nodal tissue in vivo with arterial bolus injections of (/sup 3/H)testosterone. Residual vascular radioactivity was monitored by simultaneously injecting 113m indium chelated to bovine transferrin. Both testosterone and estradiol were partially available for transport through the capillary barriers of control and neoplastic lymph nodes from the circulating albumin-bound pool. Estradiol was readily available for transport from the circulating sex hormone-binding globulin-bound pool in both control and neoplastic lymph nodes. Testosterone was not available for transport from the sex hormone-binding globulin-bound pool in control lymph nodes, but was readily available for transport in metastatic lymph nodes. Thaw-mount autoradiography and physiological measurements showed that plasma proteins such as albumin or transferrin were confined to the microcirculation compartment. The transport of protein-bound hormones into lymph node represents a mechanism of enhanced steroid hormone dissociation from the binding protein without the plasma protein per se significantly exiting the microcirculation compartment. Metabolic studies showed no measurable metabolism of (/sup 3/H)testosterone in the control lymph nodes by 60 sec after arterial injection.

• Research Organization: UCLA School of Medicine
• OSTI ID: 6647478
• Journal Information: Endocrinology; (United States), Journal Name: Endocrinology; (United States) Vol. 3; ISSN ENDOA
• Country of Publication: United States
• Language: English

Related Subjects

551001* -- Physiological Systems-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ANDROGENS
ANDROSTANES
ANIMAL CELLS
ANIMALS
AUTORADIOGRAPHY
DISEASES
ESTRADIOL
ESTRANES
ESTROGENS
HORMONES
HOURS LIVING RADIOISOTOPES
HYDROXY COMPOUNDS
INDIUM 113
INDIUM ISOTOPES
INTERMEDIATE MASS NUCLEI
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
KETONES
LABELLED COMPOUNDS
LYMPH NODES
LYMPHATIC SYSTEM
LYMPHOMAS
MAMMALS
MEMBRANE PROTEINS
METABOLISM
NEOPLASMS
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
PROTEINS
RADIOISOTOPES
RATS
RECEPTORS
RODENTS
STABLE ISOTOPES
STEROID HORMONES
STEROIDS
TESTOSTERONE
TRITIUM COMPOUNDS
TUMOR CELLS
VERTEBRATES