Cells positive for microtubule-associated protein 1B (MAP 1B) are present along rat and human efferent ductules and epididymis.
Microtubule-associated protein 1B (MAP 1B) is a neuronal cytoskeleton marker with predominant expression in the developing nervous system. The present study provides evidence for the expression of this cytoskeleton protein in non-neuronal and neuronal cells along rat and human efferent ductules and epididymis (initial segment, caput, and cauda). Reverse transcription/polymerase chain reaction and Western blot analysis were used to confirm the presence of MAP 1B (mRNA and protein) in rat tissues. Immunohistochemical studies revealed MAP-1B-positive staining in columnar ciliated cells present in efferent ductules and in narrow cells located in the initial segment, in both rat and human. MAP-1B-positive basal cells, located underneath the columnar cells, were only identified in the initial segment and caput epididymidis of the rat. Qualitative analysis of tissues from 40-day-old and 120-day-old rats indicated that the number of MAP-1B-positive ciliated, narrow, and basal cells per tubule increased with sexual maturation. These immunoreactive cells did not stain for dopamine beta-hydroxylase or acetylcholinesterase, indicating that they were not adrenergic or cholinergic in nature. Immunohistochemical studies also revealed the presence of MAP-1B-positive staining in interstitial nerve fibers in caput and cauda epididymidis from both rat and human. Thus, the expression of MAP 1B is not confined to a specific cell type in rat and human efferent ductules and epididymis. The functional significance of this cytoskeleton protein in tissues from the male reproductive tract requires further investigation.
Section of Experimental Endocrinology, Department of Pharmacology, Universidade Federal de São Paulo-Escola Paulista de Medicina, Rua 3 de maio 100, INFAR, Vila Clementino, 04044-020 São Paulo, Brazil.
Daniel B C
DB
Queiróz
Adilson M da
AM
Silva
Gabriel
G
Gutiérrez-Ospina
Catarina S
CS
Porto
Gail
G
Grossman
Peter
P
Petrusz
Maria C W
MC
Avellar
D000818:Animals; D004822:Epididymis / Q000166:cytology* / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008869:Microtubule-Associated Proteins / Q000032:analysis*; D051381:Rats; D017208:Rats, Wistar; D012152:Rete Testis / Q000166:cytology* / Q000378:metabolism*
D008869:Microtubule-Associated Proteins; C085284:microtubule-associated protein 1B