Gestational Changes in Calcitonin Gene-Related Peptide, Nerve Growth Factor, and Its Receptors in Rat Dorsal Root Ganglia

• Published in: Biology of reproduction 2001-11, Vol.65 (5), p.1601-1605
• Main Authors: LANLUA, P, GANGULA, P. R. R, TAGLIALATELA, G, YALLAMPALLI, C
• Format: Article
• Language: English
• Subjects: Animals; Biological and medical sciences; Blotting, Western; Calcitonin Gene-Related Peptide - analysis; Calcitonin Gene-Related Peptide - metabolism; Female; Fundamental and applied biological sciences. Psychology; Ganglia, Spinal - chemistry; Ganglia, Spinal - metabolism; Hormone metabolism and regulation; Immunoassay; Male; Nerve Growth Factor - analysis; Nerve Growth Factor - metabolism; Neurons - chemistry; Neurons - metabolism; Ovariectomy; Postpartum Period; Pregnancy; Pregnancy. Parturition. Lactation; Radioimmunoassay; Rats; Rats, Sprague-Dawley; Receptor, Nerve Growth Factor - analysis; Receptor, Nerve Growth Factor - metabolism; Receptor, trkA - analysis; Receptor, trkA - metabolism; Receptors, Nerve Growth Factor - analysis; Receptors, Nerve Growth Factor - metabolism; Vertebrates: reproduction
• ISSN: 0006-3363; 1529-7268
• DOI: 10.1095/biolreprod65.5.1601

In dorsal root ganglia (DRG) cell cultures, levels of calcitonin gene-related peptide (CGRP) are increased in the presence of ovarian hormones and nerve growth factor (NGF). In addition, injection of ovariectomized rats with ovarian hormones led to an increase in levels of two NGF receptors, TrkA and p75 NTR , in DRG. Thus, we hypothesized that increased levels of ovarian hormones during pregnancy may elevate the synthesis of CGRP and NGF receptors in the DRG. DRG harvested from rats on specific days of pregnancy, on Day 2 postpartum, and after ovariectomy were subjected to radioimmunoassay, Western blot analysis, and NGF immunoassay to determine levels of CGRP, TrkA and p75 NTR , and NGF, respectively. CGRP levels in rat DRG were significantly higher during pregnancy than at Day 2 postpartum or in ovariectomized rats. Levels of both TrkA and p75 NTR in DRG increased during pregnancy and remained elevated at Day 2 postpartum, but CGRP levels declined. Levels of NGF reached a statistically significant peak at Day 18 of gestation, and were not significantly reduced at Day 2 postpartum. Increased levels of ovarian steroid hormones during pregnancy may be involved in the synthesis of CGRP, however, the postpartum decreases in CGRP synthesis appear to be unrelated to NGF and its receptors.