Early spontaneous deficiency of calcitonin renal binding sites in rats with a high incidence of calcitonin-secreting tumors (WAG/Rij)

• Published in: Cancer research (Chicago, Ill.) Vol. 47; no. 13; pp. 3595 - 3598
• Main Authors: BOUIZAR, Z, ROSTENE, W. H, TREILHOU-LAHILLE, F, PIDOUX, E, MILHAUD, G, MOUKHTAR, M. S
• Format: Journal Article
• Language: English
• Published: Philadelphia, PA American Association for Cancer Research 01.07.1987
• Subjects: Aging; Animals; Autoradiography; Biological and medical sciences; Calcitonin - metabolism; Carcinoma - metabolism; Endocrinopathies; Kidney - metabolism; Kidney Cortex - metabolism; Kidney Medulla - metabolism; Medical sciences; Non tumoral diseases. Target tissue resistance. Benign neoplasms; Rats; Rats, Inbred Strains - physiology; Receptors, Calcitonin; Receptors, Cell Surface - metabolism; Thyroid Neoplasms - metabolism; Thyroid. Thyroid axis (diseases); Animal model; Rat; Rodentia; Peptide hormone; Thyroid gland; Kidney; Vertebrata; Mammalia; Urinary system; Calcitonin; Medullary carcinoma; Tumor; Hormonal receptor
• ISSN: 0008-5472; 1538-7445

Old rats of the WAG/Rij strain have a high incidence (50%) of medullary thyroid carcinoma, a calcitonin (CT)-secreting tumor. We have characterized and quantified the topographical distribution of [125I]salmon calcitonin (sCT) binding sites in the kidneys of this strain, as compared to Wistar CF rats (2% incidence of spontaneous medullary thyroid carcinoma). We report here that, up to 15 days of postnatal development, the distribution of CT-binding sites in the kidney of the WAG/Rij strain was quite similar to that found in developing and adult Wistar CF rats. However, from the age of 1 month, sCT-binding sites were dramatically reduced in both the medulla and the inner part of the kidney cortex, though plasma CT levels were not significantly different in both strains. Adult WAG/Rij rats bearing a transplanted tumor for 12 weeks had a high level of plasma calcitonin and exhibited an even greater reduction of both medullary and cortical sCT-binding sites. These results suggest that the modification in the CT-binding sites in WAG/Rij rats is not a consequence of a possible down regulation due to elevated circulating hormonal level but could be inherited and possibly associated with the later development of the tumor in this strain.