http://sedici.unlp.edu.ar:80/handle/10915/146965 2026-11-05T17:56:04Z 2026-11-05T17:56:04Z Vásquez, Rodrigo Sobrevia, Luis http://sedici.unlp.edu.ar:80/handle/10915/146981 2022-12-07T20:03:43Z 2006-06-01T00:00:00Z

Revision Physiological Mini Reviews (PMR); vol. 1, no. 11 TGF-β is one of the members of the TGF-β superfamily of growth factors, including activins/inhibins and bone morphogenic proteins (BMP). At least three TGF-β isoforms have been reported in mammals: TGF-β1, TGF-β2 and TGF-β3. Virtually all human cells produce TGF-β and express its plasma membrane receptors. Each isoform is coded by a different gene, in a tissue-specific and developmental-regulated manner. TGF-β1 mRNA is expressed in endothelial, haematopoietic and connective-tissue cells, TGF-β2 mRNA is expressed in epithelial and neuronal cells, and TGF-β3 mRNA in mesenchymal cells (1,3,25). The sequence homology is 70-80% between TGF-β isoforms and 30-40% with activins/inhibins and BMP. TGF-β1, 2 and 3 are highly conserved in mammals suggesting a critical biological function for each of these isoforms, acting as strong mediators of tissue repair through chemotaxis and angiogenesis stimulation and extracellular matrix generation (1,3,25). TGF-β1 is a 112 amino acid polypeptide which forms a homodimer with both subunits linked with a disulfide bond. TGF-β1 is synthesized as a precursor of 391 amino acids whose amino acid sequence includes TGF-β1 and the propeptide latencyassociated peptide (LAP) in the amino terminal. TGF-β1 is cleaved from LAP before the precursor is secreted from the cells, but it continues non-covalently bond to this propeptide. After being secreted, TGF-β1 is stored at the extracellular matrix as a complex formed between TGF-β1, LAP and the latent TGF-b binding protein (LTBP). The relation between TGF-β1 and LTBP through disulfide bond prevents the binding of TGF-β1 to its receptors. In vivo, TGF-β1 is released from the complex by the matrix glycoprotein thrombospondin 1 (TSP-1), which changes the conformation of LTBP (1,25).

2006-06-01T00:00:00Z TGF-β is one of the members of the TGF-β superfamily of growth factors, including activins/inhibins and bone morphogenic proteins (BMP). At least three TGF-β isoforms have been reported in mammals: TGF-β1, TGF-β2 and TGF-β3. Virtually all human cells produce TGF-β and express its plasma membrane receptors. Each isoform is coded by a different gene, in a tissue-specific and developmental-regulated manner. TGF-β1 mRNA is expressed in endothelial, haematopoietic and connective-tissue cells, TGF-β2 mRNA is expressed in epithelial and neuronal cells, and TGF-β3 mRNA in mesenchymal cells (1,3,25). The sequence homology is 70-80% between TGF-β isoforms and 30-40% with activins/inhibins and BMP. TGF-β1, 2 and 3 are highly conserved in mammals suggesting a critical biological function for each of these isoforms, acting as strong mediators of tissue repair through chemotaxis and angiogenesis stimulation and extracellular matrix generation (1,3,25). TGF-β1 is a 112 amino acid polypeptide which forms a homodimer with both subunits linked with a disulfide bond. TGF-β1 is synthesized as a precursor of 391 amino acids whose amino acid sequence includes TGF-β1 and the propeptide latencyassociated peptide (LAP) in the amino terminal. TGF-β1 is cleaved from LAP before the precursor is secreted from the cells, but it continues non-covalently bond to this propeptide. After being secreted, TGF-β1 is stored at the extracellular matrix as a complex formed between TGF-β1, LAP and the latent TGF-b binding protein (LTBP). The relation between TGF-β1 and LTBP through disulfide bond prevents the binding of TGF-β1 to its receptors. In vivo, TGF-β1 is released from the complex by the matrix glycoprotein thrombospondin 1 (TSP-1), which changes the conformation of LTBP (1,25). Gutiérrez, Antonio M. Echevarría, Miriam Whittembury, Guillermo http://sedici.unlp.edu.ar:80/handle/10915/146979 2022-12-07T20:03:44Z 2006-05-01T00:00:00Z

Revision Physiological Mini Reviews (PMR); vol. 1, no. 10 We overview the critical steps leading to the demonstration that each ~28 kD protein monomer of the water channel (or pore)¹ pierce the lipid bilayer part of the cell membrane allowing the passage of ~ 10¹³ water molecules per second. The biophysical approach gives a functional and physical image of the water pore close to what has recently been obtained from the amino acid sequence, crystallography and other advances from the cloning era of trans-membrane water transport. Paracellular “wide” water channels of some leaky epithelia are not covered here [cf. Whittembury and Reuss, 1992; Whittembury and Hill, 2000].

2006-05-01T00:00:00Z We overview the critical steps leading to the demonstration that each ~28 kD protein monomer of the water channel (or pore)¹ pierce the lipid bilayer part of the cell membrane allowing the passage of ~ 10¹³ water molecules per second. The biophysical approach gives a functional and physical image of the water pore close to what has recently been obtained from the amino acid sequence, crystallography and other advances from the cloning era of trans-membrane water transport. Paracellular “wide” water channels of some leaky epithelia are not covered here [cf. Whittembury and Reuss, 1992; Whittembury and Hill, 2000]. McCann, Samuel M. http://sedici.unlp.edu.ar:80/handle/10915/146977 2022-12-07T20:03:47Z 2006-04-01T00:00:00Z

Revision Physiological Mini Reviews (PMR); vol. 1, no. 9 A means by which the brain could control the anterior pituitary gland was discovered by B. A. Houssay et al. (1933). In the living toad they found that portal vessels drained blood from a primary capillary plexus in the median eminence (ME) down the pituitary stalk to the sinusoids in the anterior pituitary gland. Popa and Fielding found these vessels in dead animals but believed that the blood flow was upward from the pituitary to the median eminence, a conclusion also reached in the living rabbit by G. W. Harris. Later with Green (1947), he found that the flow was downward in the living rat. Since the blood pressure in the portal vessels is very low, it is likely that, depending on the conditions, flow can be either upward or downward. Additionally, the short portal vessels carry blood from the neural lobe across the intermediate lobe to the anterior lobe, thus delivering neural lobe hormones directly in high concentrations to the anterior lobe of the gland. This fact has been largely neglected.

2006-04-01T00:00:00Z A means by which the brain could control the anterior pituitary gland was discovered by B. A. Houssay et al. (1933). In the living toad they found that portal vessels drained blood from a primary capillary plexus in the median eminence (ME) down the pituitary stalk to the sinusoids in the anterior pituitary gland. Popa and Fielding found these vessels in dead animals but believed that the blood flow was upward from the pituitary to the median eminence, a conclusion also reached in the living rabbit by G. W. Harris. Later with Green (1947), he found that the flow was downward in the living rat. Since the blood pressure in the portal vessels is very low, it is likely that, depending on the conditions, flow can be either upward or downward. Additionally, the short portal vessels carry blood from the neural lobe across the intermediate lobe to the anterior lobe, thus delivering neural lobe hormones directly in high concentrations to the anterior lobe of the gland. This fact has been largely neglected. Lascano, Elena C. Negroni, Jorge A. http://sedici.unlp.edu.ar:80/handle/10915/146976 2022-12-07T20:03:48Z 2006-03-01T00:00:00Z

Revision vol. 1, no. 8; Physiological Mini Reviews (PMR) In the normoperfused heart, Ca²⁺ enters the myocardial cell through voltagedependent Ca²⁺ channels and is extruded through the sarcolemmal Ca²⁺ pump and the Na+/Ca²⁺ exchanger. During ischemia and early reperfusion, however, sarcoplasmic reticulum reuptake and sarcolemmal Ca²⁺ pump activities are impaired due to decreased ATP. In addition, owing to defective Na⁺-K⁺ pump performance and low pH favoring Na⁺ entry in exchange for H⁺ output through the Na⁺/H⁺ exchanger, the Na⁺/Ca²⁺ exchanger operates in its reverse mode incorporating Ca²⁺ to diminish increased intracellular Na⁺. Thus, the resulting impaired Ca²⁺ balance produces Ca²⁺ overload and myocardial injury probably by activation of Ca²⁺-dependent proteases which can partially destroy contractile proteins leading to decreased responsiveness of contractile filaments to Ca²⁺ (18). This chain of ischemic events is in part counteracted by activation of ATP-dependent K⁺ (KATP) channels which by allowing earlier passive K⁺ output, shortens action potential duration and reduces the time during which Ca²⁺ can enter the cell.

2006-03-01T00:00:00Z In the normoperfused heart, Ca²⁺ enters the myocardial cell through voltagedependent Ca²⁺ channels and is extruded through the sarcolemmal Ca²⁺ pump and the Na+/Ca²⁺ exchanger. During ischemia and early reperfusion, however, sarcoplasmic reticulum reuptake and sarcolemmal Ca²⁺ pump activities are impaired due to decreased ATP. In addition, owing to defective Na⁺-K⁺ pump performance and low pH favoring Na⁺ entry in exchange for H⁺ output through the Na⁺/H⁺ exchanger, the Na⁺/Ca²⁺ exchanger operates in its reverse mode incorporating Ca²⁺ to diminish increased intracellular Na⁺. Thus, the resulting impaired Ca²⁺ balance produces Ca²⁺ overload and myocardial injury probably by activation of Ca²⁺-dependent proteases which can partially destroy contractile proteins leading to decreased responsiveness of contractile filaments to Ca²⁺ (18). This chain of ischemic events is in part counteracted by activation of ATP-dependent K⁺ (KATP) channels which by allowing earlier passive K⁺ output, shortens action potential duration and reduces the time during which Ca²⁺ can enter the cell. Alleva, Karina Amodeo, Gabriela http://sedici.unlp.edu.ar:80/handle/10915/146974 2022-12-07T20:03:49Z 2006-02-01T00:00:00Z

Revision Physiological Mini Reviews (PMR); vol. 1, no. 7 More than 30 years ago, biophysicist and animal physiologists supported the hypothesis of the existence of pores facilitating water transport through membranes since certain animal structures were unusually permeable to water. Although plant physiologists also discussed the existence of water channels since the early 1960s, the survey remained marginal in the field (reviewed by Chrispeels and Maurel 1994). It was in 1992 that the hypothetical proteinaceous water channel was identified (named CHIP28, now AQP1) by Preston et. al. This discovery opened the molecular detection of homologous proteins in all kingdoms. The term “aquaporins” (AQPs) was suggested later, when other two proteins belonging to the MIP26 family (WCH-CD -from mammalian collecting ductand g-TIP -from tonoplast of Arabidopsis thaliana-) were also characterized as water channels (Agre et al., 1993). The first cloned and functionally expressed aquaporin from plants was therefore g-TIP (now TIP1;1) (Maurel et al., 1993). Since this event, plant aquaporins captured significant attention. This article intends to explore the regulatory mechanisms in plant aquaporins and to contrast them with those achievements made on their animal homologues. The aim is to merge the contributions made by both fields of research.

2006-02-01T00:00:00Z More than 30 years ago, biophysicist and animal physiologists supported the hypothesis of the existence of pores facilitating water transport through membranes since certain animal structures were unusually permeable to water. Although plant physiologists also discussed the existence of water channels since the early 1960s, the survey remained marginal in the field (reviewed by Chrispeels and Maurel 1994). It was in 1992 that the hypothetical proteinaceous water channel was identified (named CHIP28, now AQP1) by Preston et. al. This discovery opened the molecular detection of homologous proteins in all kingdoms. The term “aquaporins” (AQPs) was suggested later, when other two proteins belonging to the MIP26 family (WCH-CD -from mammalian collecting ductand g-TIP -from tonoplast of Arabidopsis thaliana-) were also characterized as water channels (Agre et al., 1993). The first cloned and functionally expressed aquaporin from plants was therefore g-TIP (now TIP1;1) (Maurel et al., 1993). Since this event, plant aquaporins captured significant attention. This article intends to explore the regulatory mechanisms in plant aquaporins and to contrast them with those achievements made on their animal homologues. The aim is to merge the contributions made by both fields of research. Candia, Oscar A. Alvarez, Lawrence J. http://sedici.unlp.edu.ar:80/handle/10915/146973 2022-12-07T20:03:52Z 2006-01-01T00:00:00Z

Revision Physiological Mini Reviews (PMR); vol. 1, no. 6 Ion-coupled fluid secretion (or absorption) is a property of epithelia, in general, and such fluid transport has been demonstrated with all ocular tissues examined to date, which include corneal endothelium and epithelium, and the epithelia of the ciliary body, lens, and conjunctiva, as well as, the retinal pigmented epithelium.

2006-01-01T00:00:00Z Ion-coupled fluid secretion (or absorption) is a property of epithelia, in general, and such fluid transport has been demonstrated with all ocular tissues examined to date, which include corneal endothelium and epithelium, and the epithelia of the ciliary body, lens, and conjunctiva, as well as, the retinal pigmented epithelium. Bouzat, Cecilia http://sedici.unlp.edu.ar:80/handle/10915/146972 2022-12-07T20:03:54Z 2005-12-01T00:00:00Z

Revision Physiological Mini Reviews (PMR); vol. 1, no. 5 Ligand binding and channel gating are dynamic processes that require precise and coordinated movements of the protein, which have recently begun to be unraveled. Desensitization still remains a complex and mysterious process. If the goal of designing new ligands targeted to specific LGICs subtypes or to mutated receptors at the origin of the disease states is to be fulfilled, we require an intimate knowledge of the structure-function relationship of them. There is hope that the new understanding of the molecular pharmacology of Cys-loop receptors will led to a new generation of more selective drugs with improved safety profiles.

2005-12-01T00:00:00Z Ligand binding and channel gating are dynamic processes that require precise and coordinated movements of the protein, which have recently begun to be unraveled. Desensitization still remains a complex and mysterious process. If the goal of designing new ligands targeted to specific LGICs subtypes or to mutated receptors at the origin of the disease states is to be fulfilled, we require an intimate knowledge of the structure-function relationship of them. There is hope that the new understanding of the molecular pharmacology of Cys-loop receptors will led to a new generation of more selective drugs with improved safety profiles. Cardinali, Daniel P. http://sedici.unlp.edu.ar:80/handle/10915/146971 2022-12-07T20:03:55Z 2005-11-01T00:00:00Z

Revision Physiological Mini Reviews (PMR); vol. 1, no. 4 Melatonin provides an innovative neuroprotective strategy by combining its effects on sleep with its cytoprotective properties. Melatonin protects against several mechanisms of neuronal death, including oxyradical-mediated damage and apoptosis implicated in the pathogenesis of a number of neurodegenerative diseases like AD, Parkinsonism, Huntington’s chorea and neurological conditions like stroke, epilepsy and brain trauma.

2005-11-01T00:00:00Z Melatonin provides an innovative neuroprotective strategy by combining its effects on sleep with its cytoprotective properties. Melatonin protects against several mechanisms of neuronal death, including oxyradical-mediated damage and apoptosis implicated in the pathogenesis of a number of neurodegenerative diseases like AD, Parkinsonism, Huntington’s chorea and neurological conditions like stroke, epilepsy and brain trauma. Cingolani, Horacio Eugenio Ennis, Irene Lucía http://sedici.unlp.edu.ar:80/handle/10915/146969 2022-12-07T20:03:56Z 2005-10-01T00:00:00Z

Revision Physiological Mini Reviews (PMR); vol. 1, no. 3 The stretching of a papillary muscle induces a sudden and immediate rise in force, due to an augmentation in myofilament Ca²⁺ responsiveness. During the next 10 to 15 minutes a progressive increase in force develops known as the “slow force response” (SFR), that is due to a progressive increase in Ca²⁺ transient amplitude. The source for this increase in Ca²⁺ transient remained obscure until we proposed a link between Ca²⁺ influx mediated by Na⁺/ Ca²⁺ (NCX) exchange in reverse mode and the activation of the Na⁺/H⁺ exchanger (NHE-1) caused by stretch;1-4 being the increase in the Ca²⁺ transient secondary to the increase in intracellular Na⁺ concentration ([Na+]i). It is known that the increase in [Na⁺]i can induce an increase in intracellular Ca²⁺ levels ([Ca²⁺ ]i) through the NCX either as a result of a decrease in Ca²⁺ efflux (decreased forward mode) or an increase in Ca²⁺ entry (increased reverse mode). The fact that after myocardial stretch there is no increase in diastolic [Ca²⁺ ]i 1,5 as would be expected for a decrease in Ca²⁺ efflux, suggests that the reverse mode of NCX is the mechanism involved in the increase in Ca²⁺ transient.1The SFR, the increase in [Na⁺]i and the increase in Ca²⁺ transient can be abolished by blocking the Angiotensin II (Ang II) AT1 receptors with losartan; the endothelin (ET) ETA receptors by BQ123 and by inhibition of the NHE-1.6

2005-10-01T00:00:00Z The stretching of a papillary muscle induces a sudden and immediate rise in force, due to an augmentation in myofilament Ca²⁺ responsiveness. During the next 10 to 15 minutes a progressive increase in force develops known as the “slow force response” (SFR), that is due to a progressive increase in Ca²⁺ transient amplitude. The source for this increase in Ca²⁺ transient remained obscure until we proposed a link between Ca²⁺ influx mediated by Na⁺/ Ca²⁺ (NCX) exchange in reverse mode and the activation of the Na⁺/H⁺ exchanger (NHE-1) caused by stretch;1-4 being the increase in the Ca²⁺ transient secondary to the increase in intracellular Na⁺ concentration ([Na+]i). It is known that the increase in [Na⁺]i can induce an increase in intracellular Ca²⁺ levels ([Ca²⁺ ]i) through the NCX either as a result of a decrease in Ca²⁺ efflux (decreased forward mode) or an increase in Ca²⁺ entry (increased reverse mode). The fact that after myocardial stretch there is no increase in diastolic [Ca²⁺ ]i 1,5 as would be expected for a decrease in Ca²⁺ efflux, suggests that the reverse mode of NCX is the mechanism involved in the increase in Ca²⁺ transient.1The SFR, the increase in [Na⁺]i and the increase in Ca²⁺ transient can be abolished by blocking the Angiotensin II (Ang II) AT1 receptors with losartan; the endothelin (ET) ETA receptors by BQ123 and by inhibition of the NHE-1.6 de Bold, Adolfo J. http://sedici.unlp.edu.ar:80/handle/10915/146967 2022-12-07T20:03:58Z 2005-09-01T00:00:00Z

Revision Physiological Mini Reviews (PMR); vol. 1, no. 2 Two polypeptide hormones are produced, stored and secreted in a regulated manner by cardiac muscle cells (cardiocytes) of the atria of the heart of mammals. These are atrial natriuretic factor (ANF)1-3 and brain natriuretic peptide (BNP).4 They form part of a family of hormones referred to as natriuretic peptides (NP). A third member: CNP, is not natriuretic and is not produced by cardiocytes. Both ANF and BNP are co-stored in atrial cardiocytes in storage granules referred to as specific atrial granules. Some confusion has recently developed in the clinical literature as to the precise cell type where this secretory function resides, as well as to the peptide storage form and the location of the secretory function, which, of late, is often quoted as being the atria for ANF and the ventricular muscle for BNP. By Northern blot analysis, immunocytochemistry, in situ hybridization, radioimmunoassay and oligonucleotide array, ANF and BNP are far more abundant in the atria than the ventricles. In fact, the level of expression of NP in the normal ventricles is negligible compared to that of the atria.

2005-09-01T00:00:00Z Two polypeptide hormones are produced, stored and secreted in a regulated manner by cardiac muscle cells (cardiocytes) of the atria of the heart of mammals. These are atrial natriuretic factor (ANF)1-3 and brain natriuretic peptide (BNP).4 They form part of a family of hormones referred to as natriuretic peptides (NP). A third member: CNP, is not natriuretic and is not produced by cardiocytes. Both ANF and BNP are co-stored in atrial cardiocytes in storage granules referred to as specific atrial granules. Some confusion has recently developed in the clinical literature as to the precise cell type where this secretory function resides, as well as to the peptide storage form and the location of the secretory function, which, of late, is often quoted as being the atria for ANF and the ventricular muscle for BNP. By Northern blot analysis, immunocytochemistry, in situ hybridization, radioimmunoassay and oligonucleotide array, ANF and BNP are far more abundant in the atria than the ventricles. In fact, the level of expression of NP in the normal ventricles is negligible compared to that of the atria. Cereijido, M. Shoshani, L. Contreras, R. G. Larre, I. http://sedici.unlp.edu.ar:80/handle/10915/146966 2022-12-07T20:04:00Z 2005-08-01T00:00:00Z

Revision Physiological Mini Reviews (PMR); vol. 1, no. 1 The cells of metazoan organisms exchange nutrients and wastes with an extremely thin layer of interstitial milieu, that would be quickly spoiled, were it not for a circulatory apparatus that constantly restores nutrients and takes away waste products by carrying them to and from large areas of epithelia (intestinal, renal, lung, gills, etc.), where they are finally exchanged with the external environment. Therefore metazoans ultimately depend on the ability of their epithelia to transport substances in a net amount towards the outside of the organism or in the opposite direction. In the second half of the Nineteen Century Emile Du Bois Raymond found that the frog skin maintains a spontaneous electrical potential across, and in 1904 G. Galeotti proposed that it was due to a higher Na+ permeability in the inward than in the outward direction, but his suggestion was rejected lest that it would be in violation of the first and second laws of thermodynamics (for reviews see Cereijido and Rotunno 1971, Cereijido et al. 2004). To circumvent this difficulty it was proposed that energy would be afforded by cellular metabolism. Yet this was also refuted because, according to Curie’s Principle, phenomena of different tensorial order cannot be coupled, i.e. since the transport of Na+ is a vectorial phenomenon (it occurs in the outside −> inside direction) it cannot be driven by a scalar phenomenon (in those days chemical reactions were assumed to be scalar, and therefore was not expected to proceed in a given direction of space). Half a century later electric and tracer methods unambiguously demonstrated that the frog skin can actually transport a net amount of Na+ in the inward direction, in the absence of an external electrochemical potential gradient. This demanded, of course, a closer look at the arguments that had stood in the way of accepting that metabolism can drive Na+ transport.

2005-08-01T00:00:00Z The cells of metazoan organisms exchange nutrients and wastes with an extremely thin layer of interstitial milieu, that would be quickly spoiled, were it not for a circulatory apparatus that constantly restores nutrients and takes away waste products by carrying them to and from large areas of epithelia (intestinal, renal, lung, gills, etc.), where they are finally exchanged with the external environment. Therefore metazoans ultimately depend on the ability of their epithelia to transport substances in a net amount towards the outside of the organism or in the opposite direction. In the second half of the Nineteen Century Emile Du Bois Raymond found that the frog skin maintains a spontaneous electrical potential across, and in 1904 G. Galeotti proposed that it was due to a higher Na+ permeability in the inward than in the outward direction, but his suggestion was rejected lest that it would be in violation of the first and second laws of thermodynamics (for reviews see Cereijido and Rotunno 1971, Cereijido et al. 2004). To circumvent this difficulty it was proposed that energy would be afforded by cellular metabolism. Yet this was also refuted because, according to Curie’s Principle, phenomena of different tensorial order cannot be coupled, i.e. since the transport of Na+ is a vectorial phenomenon (it occurs in the outside −> inside direction) it cannot be driven by a scalar phenomenon (in those days chemical reactions were assumed to be scalar, and therefore was not expected to proceed in a given direction of space). Half a century later electric and tracer methods unambiguously demonstrated that the frog skin can actually transport a net amount of Na+ in the inward direction, in the absence of an external electrochemical potential gradient. This demanded, of course, a closer look at the arguments that had stood in the way of accepting that metabolism can drive Na+ transport.