Maria L. Vitale, Ph.D.

Associate Professor

Department of pathology and cell biology 

Faculty of Medecine, Université de Montréal

Pavillon Roger-Gaudry, R-804

2900 Edouard-Montpetit, Montréal, Québec

H3T 1J4

Tel.: (514) 343-7543

Fax: (514) 343-5755

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Field of research:

Our research has two aims. Aim 1) To study the role of the actin cytoskeleton in different cellular events in particular, the exocytosis, apoptosis and cell motility. Aim2) To study the role of the gap junctions and of the intercellular communication mediated by these junctions in hormone secretion. In our studies, we use cell biology techniques (cell culture, Western blots, immunoprecipitatrion, etc), molecular biology techniques (PRC, Northen blots), and morphological studies (fluorescence microscopy and confocal microscopy).


Resume of recent results:

We recently demonstrated the participation of the isoform B of non-muscle myosin II in cell contraction during apoptosis. In addition, we showed that this particular myosin II isoform contributes to the modulation of several polarity complexes. Our studies on the role of gap junctions in hormone secretion demonstrated that connexin 43, a gap junction protein, expressed by the anterior pituitary folliculo-stellate cells, is a target of modulators of the immune and endocrine responses.


Laboratory members:



Email Address

Christopher Garcia

M.Sc student

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Ahmed Barry

M.Sc student

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Publications :



1.   Trifaró JM, Vitale ML, Rodriguez Del Castillo A.

Cytoskeleton and molecular mechanisms in neurotransmitter release by neurosecretory cells.

Journal of Pharmacology. 1992: 225: 83-104, 1992.


2.   Trifaró JM, Vitale ML, Rodriguez Del Castillo A.

Scinderin and chromaffin cell actin network dynamics during neurotransmitter release.

Journal of Physiology, Paris. 1993; 87:89-106.


3.   Trifaró JM, Vitale ML.

Cytoskeleton dynamics during neurotransmitter release.

Trends in Neurosciences. 1993; 16:466-72.


4.   Vitale ML, Chiocchio SR.

Serotonin, a neurotransmitter involved in the regulation of luteinizing hormone release.

Endocrine Reviews. 1993; 14:480-93.


5.   Vitale ML

The role of the actin cytoskeleton in hormone secretion by exocytosis.

Recent Research Developments in Endocrinology 2001; 2:251-260.


6.   Pelletier R-M, Vitale ML

Las uniones oclusivas del testículo, epidídimo y conducto deferente

Boletín de la Sociedad Argentina de Andrología 2003; 12:53-72.


7.   Vitale ML

Dopamine-mediated regulation of the actin cytoskeleton in prolactin-secreting cells.

In: “Dopamine Research Focus”, Nova Science Publishers, Inc., Hauppauge, NY, USA. 2007



Full papers


  1. Parisi MN, Vitale ML, Chiocchio SR, Tramezzani JH

Serotonin levels in rat median eminence change during the estrous cycle.

Acta Physiol.Pharmacol. Latinoamericana 1983; 33:89-91.


 2.  Vitale ML, Parisi MN, Chiocchio SR, Tramezzani JH

            Median eminence serotonin involved in proestrous gonadotropin release.

            Neuroendocrinology 1984; 39:136-141.


 3.  Vitale ML, Parisi MN, Chiocchio SR, Tramezzani JH

Serotonin stimulates gonadotropin release by acting directly on the median eminence.

            Acta Physiol.Pharmacol. Latinoamericana 1985; 35:473-479.


 4.  Vitale ML, Parisi MN, Chiocchio SR, Tramezzani JH

Serotonin induces gonadotropin release through stimulation of LH-releasing hormone release from the median eminence.

            Journal of Endocrinology 1986; 111:309-315.


 5.  Parisi MN, Vitale ML, Villar MJ, Estivariz FE, Chiocchio SR, Tramezzani JH

Serotonergic terminals in the anterior hypothalamic nucleus involved in the prolactin release during lactation.

            Endocrinology 1987; 120:2402-2412.


 6.  Villar MJ, Vitale ML, Parisi MN

Dorsal raphe serotonergic projection to the retina. A combined peroxidase tracing-neurochemical high performance liquid chromatography study in the rat.

            Neuroscience 1987; 22:681-686.


 7.  Vitale ML, Villar MJ, Chiocchio SR, Tramezzani JH

Dorsal raphe lesion alters the estrous cycle and the preovulatory gonadotropin release.

            Neuroendocrinology 1987; 46:252-257.


 8.  Villar MJ, Vitale ML, Hökfelt T, Verhofstadt AAJ

Dorsal raphe serotonergic branching neurons projecting both to the lateral geniculate body and the superior colliculus. A combined tracing-immunochemical study in the rat.

            Journal of Comparative Neurology 1988; 277:126-140.


 9.  Campos MB, Vitale ML, Calandra RS, Chiocchio SR

Serotonergic innervation of the rat testis.

            Journal of Reproduction and Fertility 1990; 80:475-479.


10.  Parisi MN, Vitale ML, Chiocchio SR

Model dependent effect of VIP on prolactin secretion.

            Hormone and Metabolic Research 1990; 22:194-195.


11.  Rodríguez Del Castillo A, Lemaire S, Tchakarov L, Jeyapragasan M, Doucet J-P, Vitale ML, Trifaró JM

Chromaffin cell scinderin, a novel calcium-dependent actin filament-severing protein.

            EMBO Journal 1990; 9:43-52.


12.  Campos MB, Vitale ML, Ritta MN, Chiocchio SR, Calandra RS

Catecholamine distribution in adult rat testis.

            Andrologia 1990; 22:247-250.


13.  Tchakarov L, Vitale ML, Jeyapragasan M, Rodríguez Del Castillo A, Trifaró JM.

Expression of scinderin, an actin filament-severing protein, in different tissues.

            FEBS Letters 1990; 268:209-212.


14.  Chiocchio SR, Parisi MN, Vitale ML, Tramezzani JH

Suckling induced changes in vasoactive intestinal polypeptide (VIP) concentration in hypothalamic areas implicated in the control of prolactin release.

            Neuroendocrinology 1991; 54:77-82.


15. Vitale ML, Rodríguez Del Castillo A, Tchakarov L, Trifaró JM

Cortical filamentous actin disassembly and scinderin redistribution during chromaffin cell stimulation precede exocytosis. A phenomenon not exhibited by gelsolin.

            Journal of Cell Biology 1991; 113:1057-106.


16. Rodríguez Del Castillo A, Vitale ML, Tchakarov L, Trifaró JM

Human platelets contain scinderin, a Ca2+-dependent actin-filament severing protein.

            Thrombosis and Haemostasis 1992; 67:248-25.


17. Trifaró JM, Vitale ML, Rodríguez Del Castillo A

Cytoskeleton and molecular mechanisms in neurotransmitter release by neurosecretory cells.

            European Journal of Pharmacology (Molecular Pharmacology section) 1992; 225:83-104.


18. Rodríguez Del Castillo A, Vitale ML, Trifaró JM

Ca2+ and pH determine the interaction of chromaffin cell scinderin with phosphatidylserine (PS) and phosphatidylinositol 4,5 biphosphate (PIP2) and its cellular distribution during nicotinic receptor stimulation and protein kinase C activation.

            Journal of Cell Biology 1992; 119:797-810.


19. Vitale ML, Rodríguez Del Castillo A, Trifaró JM

Loss and Ca2+-dependent retention of scinderin in digitonin-permeabilized chromaffin cells. Correlation with Ca2+-evoked catecholamine secretion.

            Journal of Neurochemistry 1992; 59:1717-1728.


20. Vitale ML, Rodríguez Del Castillo A, Trifaró JM

Protein kinase C activation by phorbol esters induces chromaffin cell cortical filamentous actin disassembly and increases the initial rate of exocytosis in response to nicotininc receptor stimulation.

            Neuroscience 1992; 51:463-474.


21. Trifaró JM, Rodríguez Del Castillo, Vitale ML

Dynamic changes in chromaffin cell cytoskeleton as prelude to exocytosis.

            Molecular Neurobiology 1992; 6:339-358.


22. Pelletier RM, Vitale ML

Filipin versus enzymatic localization of cholesterol in guinea pig, mink and mallard duck testicular cells.

            Journal of Histochemistry and Cytochemistry 1994; 42:1539-1554.


23. Marcu MG, Rodríguez Del Castillo A, Vitale ML, Trifaró JM

Molecular cloning and functional expression of chromaffin cell scinderin indicates that it belongs to the family of Ca2+-dependent F-actin severing proteins.

            Molecular and Cellular Biochemistry 1994; 141:153-165.


24. Vitale ML, Seward EP, Trifaró J-M

Chromaffin cell cortical actin network dynamics control the size of the release-ready vesicle pool and the initial rate of exocytosis.

            Neuron 1995; 14:353-363.


25. Pelletier RM, Okawara Y, Vitale ML, Anderson JM

Differential distribution of the tight junction associated protein ZO-1α+ and α- isoforms in guinea pig Sertoli cells: a possible association with F-actin and G-actin.

            Biology of Reproduction 1997; 57:367-376.


26. Gandía L, Vitale ML, Villaroya M, Ramírez-Lavergne C, García AG, Trifaró JM

Differential effects of forskolin and 1,9 dideoxyforskolin on nicotine receptor and K+-induced responses in chromaffin cells.

            European Journal of Pharmacology 1997; 329:189-199.


27. Carbajal ME†, Vitale ML

The cortical actin cytoskeleton of lactotrophs as an intracellular target for the control of prolactin secretion.

Endocrinology 1997;138:5374-5384.


28. Glavinovic MI, Vitale ML, Trifaró J-M.

Comparison of vesicular volume and quantal size in bovine chromaffin cell.

            Neuroscience 1998; 85:957-968.


29. Pelletier RM, Trifaró JM, Carbajal ME†, Okawara Y, Vitale ML

Calcium-dependent actin filament-severing protein scinderin levels and localization in the bovine testis, epididymis and spermatozoa.

            Biology of Reproduction 1999; 60: 1128-1136.


30. Nguyen B*, Carbajal ME†, Vitale ML

Intracellular mechanisms involved in dopamine-induced actin cytoskeleton organization and maintenance of a round phenotype in cultured rat lactotropes.

            Endocrinology 1999; 140: 3467-3477.


31. Cardin J*,Carbajal ME†; Vitale ML

Biochemical and morphological diversity of folliculo-stellate cells in the mink (Mustela vison) anterior pituitary.

            General and Comparative Endocrinology 2000; 120:75-87.


32. Vitale ML, Cardin J*, Gilula NB, Carbajal ME†, Pelletier R-M

Dynamics of connexin 43 levels and distribution in the mink (Mustela vison) anterior pituitary are associated with seasonal changes in anterior pituitary prolactin content.

            Biology of Reproduction 2001; 64:625-633.


33. Kabbaj O‡, Holm C, Vitale ML, Pelletier R-M

Expression, activity and subcellular localization of the testicular hormone-sensitive lipase during post-natal development in guinea pig.

            Biology of Reproduction 2001; 65:601-612.


34. Kabbaj O‡, Holm C, Rose J, Yoon SR‡, Vitale ML1, Pelletier R-M1

Relationship of the hormone sensitive lipase (HSL)-mediated modulation of cholesterol metabolism in individual compartments of the testis to serum pituitary hormone and testosterone concentrations in a seasonal breeder, the mink (Mustela vison).

            Biology of Reproduction 2003; 68:722-734.

            1 les deux auteurs doivent être considérés auteurs senior.


35. Vitale ML, Carbajal ME†

Involvement of myosin II in dopamine-induced reorganization of the lactotroph cell’s cytoskeleton.

            Journal of Histochemistry and Cytochemistry 2004; 52:517-527.


36. Zheng GF*, Solinet S‡, Pelletier R-M, Vitale ML

Actin cytoskeleton remodelling in the anterior pituitary folliculostellate cell line TtT/GF: Participation of the actin-binding protein cortactin.

            Journal of Molecular Histology 2005; 36:461-474.


37. Fortin M-E*, Pelletier R-M, Meilleur MA*, Vitale ML

Modulation of GJA1 turnover and intercellular communication by proinflammatory cytokines in the anterior pituitary folliculostellate cell line TtT/GF.

            Biology of Reproduction 2006; 74:2-12.


38. Akpovi CD‡, Yoon SR‡, Vitale ML, and Pelletier R-M

Predominance of one of the SR-BI isoforms is associated with increased esterified cholesterol levels not apoptosis in mink testis.

            Journal of Lipid Research 2006; 47:2233-2247.


39. Meilleur M-A*, Akpovi CD‡, Pelletier R-M, Vitale ML

TNF-α-induced anterior pituitary folliculostellate TtT/GF cell uncoupling is mediated by Cx43 dephosphorylation
Endocrinology 2007; 148:5913-5924.


40. Solinet, S‡, Vitale ML

Isoform B of Myosin II heavy chain mediates actomyosin contractility during TNFα-induced apoptosis

            Journal of Cell Science 2008; 121:1681-1692.


41. Pelletier R-M, Yoon SR‡, Akpovi CD‡, Silvas E*, Vitale ML

Defects in the regulatory clearance mechanisms favor the breakdown of self-tolerance during spontaneous autoimmune orchitis.

American Journal of Physiology. Regulatory, Integrative and Comparative Physiology 2009; 296: R743-R762.


42. Vitale ML, Akpovi CD†, Pelletier R.-M

Cortactin/tyrosine-phosphorylated cortactin interaction with connexin 43 in mouse seminiferous tubules.

            Microscopy Research and Technique 2009;72:856-867


43. Pelletier R-M, Akpovi CD†, Day R, Vitale ML

Cx43 expression, phosphorylation and distribution in the normal and autoimmune orchitic testis with a look at gap junctions joining germ cell-to-germ cells.

American Journal of Physiology. Regulatory, Integrative and Comparative Physiology 2011;300:R121-R139


44. Solinet S‡,Akpovi CD†, Garcia GJ*,Barry A*, Vitale ML

Myosin IIB deficiency in embryonic fibroblasts affects regulators and core members of the par polarity complex.

            Histochemistry and Cell Biology 2011 (in press/sous presse)



† stagiaire post-doctorale/PDF, *étudiant de maîtrise/M.Sc student; ‡ étudiant au doctorat/Ph.D. student




- Fonds de la Recherche en Santé du Québec

Chercheur junior II 1996/06-1998/05


- Fonds de la Recherche en Santé du Québec

Chercheur senior 1998/06-2002/05


- Fonds de la Recherche en Santé du Québec

Chercheur-nationaux 2002/06-2007/05