This Article Full Text Full Text (PDF) Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Copyright Permission Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Chiarenza, C. Articles by Palombi, F. Search for Related Content PubMed PubMed Citation Articles by Chiarenza, C. Articles by Palombi, F.

Platelet-Derived Growth Factor-BB Stimulates Hypertrophy of Peritubular Smooth Muscle Cells from Rat Testis in Primary Cultures¹

Department of Histology and Medical Embryology and Centro Acidi Nucleici (E.B.), Consiglio Nazionale delle Ricerche, La Sapienza University, 00161 Rome, Italy

Address all correspondence and requests for reprints to: Dr. Fioretta Palombi, Department of Histology and Medical Embryology, Via A. Scarpa 14; 00161 Rome, Italy. E-mail: fioretta.palombi{at}uniroma1.it

The tunica propria of seminiferous tubules contains a particular type of smooth muscle cell (myoid cells) arranged in a contractile epithelioid layer that is responsible for sperm and tubular fluid flow. Unlike other types of smooth muscle (SM) cells, highly purified populations of peritubular smooth muscle cells (PSMC) survive and maintain their contractile phenotype in primary cultures in controlled conditions. We used this culture model to investigate the response of the SM contractile phenotype to prolonged exposure to platelet-derived growth factor (PDGF), one of the main factors involved in vascular SM pathologies. We observed that 4-day continuous exposure of PSMC to PDGF-BB at nanomolar concentrations in plain medium enhances contractile phenotype traits and induces cell hypertrophy without inducing proliferation. In Northern and Western blotting experiments, SM--actin transcript and protein were found to be markedly increased in the PDGF-BB-treated samples, which is in line with the formation of conspicuous SM--actin-containing stress fibers. Moreover, binding sites for endothelin-1 were increased, and the calcium response to the contractile agonist, determined in single fura-2-loaded cells, was enhanced. In response to PDGF-BB, the cells underwent immediate, transient contraction, as seen in a scanning electron microscope, followed by a gradual increase in size, as evaluated by cytofluorometry, and enhancement of protein synthesis. The observed pattern of response to PDGF-BB was not accompanied by cell proliferation, as assessed by [³H]thymidine incorporation and direct cell counts. Unlike other SM cell types, in which proliferation and loss of contractile traits are induced by PDGF, chronic treatment of PSMC with this growth factor results in hypertrophy rather than hyperplasia.

This article has been cited by other articles:

				R. V. Hoch and P. Soriano Roles of PDGF in animal development Development, October 15, 2003; 130(20): 4769 - 4784. [Abstract] [Full Text] [PDF]

				S. Basciani, S. Mariani, M. Arizzi, S. Ulisse, N. Rucci, E. A. Jannini, C. D. Rocca, A. Manicone, C. Carani, G. Spera, et al. Expression of Platelet-Derived Growth Factor-A (PDGF-A), PDGF-B, and PDGF Receptor-{alpha} and -{beta} during Human Testicular Development and Disease J. Clin. Endocrinol. Metab., May 1, 2002; 87(5): 2310 - 2319. [Abstract] [Full Text] [PDF]

				F. BARONE, A. A. GENAZZANI, A. CONTI, G. C. CHURCHILL, F. PALOMBI, E. ZIPARO, V. SORRENTINO, A. GALIONE, and A. FILIPPINI A pivotal role for cADPR-mediated Ca2+ signaling: regulation of endothelin-induced contraction in peritubular smooth muscle cells FASEB J, May 1, 2002; 16(7): 697 - 705. [Abstract] [Full Text] [PDF]