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Showing papers by "University of Chicago published in 1990"


Journal ArticleDOI
TL;DR: In this article, it is shown that many particular choices among possible neurophysiological assumptions are equivalent, in the sense that for every net behaving under one assumption, there exists another net which behaves under another and gives the same results, although perhaps not in the same time.

14,937 citations


Journal ArticleDOI
TL;DR: A new method for automatic indexing and retrieval to take advantage of implicit higher-order structure in the association of terms with documents (“semantic structure”) in order to improve the detection of relevant documents on the basis of terms found in queries.
Abstract: A new method for automatic indexing and retrieval is described. The approach is to take advantage of implicit higher-order structure in the association of terms with documents (“semantic structure”) in order to improve the detection of relevant documents on the basis of terms found in queries. The particular technique used is singular-value decomposition, in which a large term by document matrix is decomposed into a set of ca. 100 orthogonal factors from which the original matrix can be approximated by linear combination. Documents are represented by ca. 100 item vectors of factor weights. Queries are represented as pseudo-document vectors formed from weighted combinations of terms, and documents with supra-threshold cosine values are returned. initial tests find this completely automatic method for retrieval to be promising.

12,443 citations


Journal ArticleDOI
TL;DR: In this article, the authors argue that firms compete for reputational status in institutional fields and attempt to influence other stakeholders' assessments by signaling firms' salient advantages by signaling their salient advantages.
Abstract: Firms compete for reputational status in institutional fields. Managers attempt to influence other stakeholders' assessments by signaling firms' salient advantages. Stakeholders gauge firms' relati...

4,862 citations


Journal ArticleDOI
TL;DR: The frequency of a given gene in a population may be modified by a number of conditions including recurrent mutation to and from it, migration, selection of various sorts and, far from least in importance, were chance variation.

4,833 citations


Journal ArticleDOI
TL;DR: The authors investigated the relation between Tobin's Q and the structure of equity ownership for a sample of 1,173 firms for 1976 and 1,093 firms for 1986 and found a significant curvilinear relation between Q and common stock owned by corporate insiders.

4,567 citations


Journal ArticleDOI
TL;DR: AR and ER may modulate nonolfactory sensory information as well since labeled cells were found in regions involved in the central relay of somatosensory information, including the mesencephalic nucleus of the trigeminal nerve, the ventral thalamic nuclear group, and the dorsal horn of the spinal cord.
Abstract: The distribution of cells that express mRNA encoding the androgen (AR) and estrogen (ER) receptors was examined in adult male and female rats by using in situ hybridization. Specific labeling appeared to be largely, if not entirely, localized to neurons. AR and ER mRNA-containing neurons were widely distributed in the rat brain, with the greatest densities of cells in the hypothalamus, and in regions of the telencephalon that provide strong inputs in the medial preoptic and ventromedial nuclei, each of which is thought to play a key role in mediating the hormonal control of copulatory behavior, as well as in the lateral septal nucleus, the medial and cortical nuclei of the amygdala, the amygdalohippocampal area, and the bed nucleus of the stria terminalis. Heavily labeled ER mRNA-containing cells were found in regions known to be involved in the neural control of gonadotropin release, such as the anteroventral periventricular and the arcuate nuclei, but only a moderate density of labeling for AR mRNA was found over these nuclei. In addition, clearly labeled cells were found in regions with widespread connections throughout the brain, including the lateral hypothalamus, intralaminar thalamic nuclei, and deep layers of the cerebral cortex, suggesting that AR and ER may modulate a wide variety of neural functions. Each part of Ammon's horn contained AR mRNA-containing cells, as did both parts of the subiculum, but ER mRNA appeared to be less abundant in the hippocampal formation. Moreover, AR and ER mRNA-containing cells were also found in olfactory regions of the cortex and in both the main and accessory olfactory bulbs. AR and ER may modulate nonolfactory sensory information as well since labeled cells were found in regions involved in the central relay of somatosensory information, including the mesencephalic nucleus of the trigeminal nerve, the ventral thalamic nuclear group, and the dorsal horn of the spinal cord. Furthermore, heavily labeled AR mRNA-containing cells were found in the vestibular nuclei, the cochlear nuclei, the medial geniculate nucleus, and the nucleus of the lateral lemniscus, which suggests that androgens may alter the central relay of vestibular and auditory information as well. However, of all the regions involved in sensory processing, the heaviest labeling for AR and ER mRNA was found in areas that relay visceral sensory information such as the nucleus of the solitary tract, the area postrema, and the subfornical organ. We did not detect ER mRNA in brainstem somatic motoneurons, but clearly labeled AR mRNA-containing cells were found in motor nuclei associated with the fifth, seventh, tenth, and twelfth cranial nerves. Similarly, spinal motoneurons contained AR but not ER mRNA.(ABSTRACT TRUNCATED AT 400 WORDS)

2,058 citations


Posted Content
TL;DR: In this article, the authors consider how prior outcomes are combined with the potential payoffs offered by current choices, and propose an editing rule to describe how decision makers frame such problems. And they also present data from real money experiments supporting a "house money effect" (increased risk seeking in the presence of a prior gain) and "break-even effects" (that outcomes which offer a chance to break even are especially attractive).
Abstract: How is risk-taking affected by prior gains and losses? While normative theory implores decision makers to only consider incremental outcomes, real decision makers are influenced by prior outcomes. We first consider how prior outcomes are combined with the potential payoffs offered by current choices. We propose an editing rule to describe how decision makers frame such problems. We also present data from real money experiments supporting a "house money effect" (increased risk seeking in the presence of a prior gain) and "break-even effects" (in the presence of prior losses, outcomes which offer a chance to break even are especially attractive).

1,973 citations


Posted Content
TL;DR: The authors showed that in most countries, rent seeking rewards talent more than entrepreneurship does, leading to stagnation, and showed that countries with a higher proportion of engineering college majors grow faster; whereas countries with higher proportions of law concentrators grow slower.
Abstract: A country's most talented people typically organize production by others, so they can spread their ability advantage over a larger scale. When they start firms, they innovate and foster growth, but when they become rent seekers, they only redistribute wealth and reduce growth. Occupational choice depends on returns to ability and to scale in each sector, on market size, and on compensation contracts. In most countries, rent seeking rewards talent more than entrepreneurship does, leading to stagnation. Our evidence shows that countries with a higher proportion of engineering college majors grow faster; whereas countries with a higher proportion of law concentrators grow slower.

1,889 citations


Posted Content
TL;DR: In this article, a model of growth departs from both the Malthusian and neoclassical approaches by including investments in human capital and assumes that rates of return on human capital investments rise, rather than, decline, as the stock of human capital increases, until the stock becomes large.
Abstract: Our model of growth departs from both the Malthusian and neoclassical approaches by including investments in human capital We assume, crucially, that rates of return on human capital investments rise, rather than, decline, as the stock of human capital increases, until the stock becomes large This arises because the education sector uses human capital note intensively than either the capital producing sector of the goods producing sector This produces multiple steady scares: an undeveloped steady stare with little human capital, low rates of return on human capital investments and high fertility, and a developed steady stats with higher rates of return a large, and, perhaps, growing stock of human capital and low fertility Multiple steady states mean that history and luck are critical determinants of a country's growth experience

1,829 citations


Journal ArticleDOI
TL;DR: In this paper, the authors argue that some investors are not fully rational and their demand for risky assets is affected by their beliefs or sentiments that are not completely justified by fundamental news.
Abstract: This paper reviews an alternative to the efficient markets approach that we and others have recently pursued. Our approach rests on two assumptions. First, some investors are not fully rational and their demand for risky assets is affected by their beliefs or sentiments that are not fully justified by fundamental news. Second, arbitrage - defined as trading by fully rational investors not subject to such sentiment - is risky and therefore limited. The two assumption together imply that changes in investors sentiment are not fully countered by arbitrageurs and so affect security returns. We argue that this approach to financial markets is in many ways superior to the efficient markets paradigm. Our case for the noise trader approach is threefold. First, theoretical models with limited arbitrage are both tractable and more plausible than models with perfect arbitrage. The efficient markets hypithesis obtains only as an extreme case of perfect riskless arbitrage that unlikely to apply in practice. Second, the investors sentiment/ limited arbitrage approach yields a more accurate description of financial markets than the efficient markets paradigm. The approach not only explains the available anomalies, but also readly explains board features of financial markets such as trading volume and actual investment strategies. Third, and most importantly, this approach yields new and testable implications about asset prices, some of which have been proved to be consistent with the data. It is absolutely not true that introducing a degree of irrationality of some investors into models of financial markets "eliminates all discipline and can explain anything".

1,513 citations



Journal ArticleDOI
16 Nov 1990-Cell
TL;DR: Yeast telomeres exert a position effect on the transcription of nearby genes, an effect that is under epigenetic control as demonstrated by phenotype and mRNA analyses.

Journal ArticleDOI
TL;DR: This article examined the effects of job security provisions on employment in European countries and found that the severance pay requirements reduce employment, and that new workers are less likely to be hired in a perfectly functioning market.
Abstract: European countries have enacted various job security provisions over the last 30 years. Employers are required to pay workers on separation or to give advance notice of termination. In anything less than a perfectly functioning market, there are effects of the provisions on employment. Incumbents are more likely to retain their jobs, but new workers are less likely to be hired. An examination of the European data suggests that severance pay requirements reduce employment.

Journal ArticleDOI
TL;DR: Morphometric studies of immature cerebral cortex in humans show developmental changes extending up to the time of adolescence, which may form the anatomical substrate for neural plasticity and for certain types of early learning.

Journal ArticleDOI
TL;DR: In this article, necessary and sufficient conditions for the stationarity and ergodicity of the GARCH(l.l) process were established, and it was shown that the IGARCH(1,1) process with no drift converges almost surely to zero.
Abstract: This paper establishes necessary and sufficient conditions for the stationarity and ergodicity of the GARCH(l.l) process. As a special case, it is shown that the IGARCH(1,1) process with no drift converges almost surely to zero, while IGARCH(1,1) with a positive drift is strictly stationary and ergodic. We examine the persistence of shocks to conditional variance in the GARCH(l.l) model, and show that whether these shocks "persist" or not depends crucially on the definition of persistence. We also develop necessary and sufficient conditions for the finiteness of absolute moments of any (including fractional) order.

Journal ArticleDOI
TL;DR: A secreted inhibitor of angiogenesis that is controlled by a tumor suppressor gene in hamster cells has been found to be similar to a fragment of the platelet and matrix protein thrombospondin, which demonstrates a function for the ubiquitous adhesive glycoprotein thromBosponin that is likely to be important in the normal physiological down-regulation of neovascularization.
Abstract: A secreted inhibitor of angiogenesis that is controlled by a tumor suppressor gene in hamster cells has been found to be similar to a fragment of the platelet and matrix protein thrombospondin. The two proteins were biochemically similar and immunologically crossreactive and could substitute for one another in two functional assays. Human thrombospondin inhibited neovascularization in vivo and endothelial cell migration in vitro, as does the hamster protein, gp140. gp140 sensitized smooth muscle cells to stimulation by epidermal growth factor, as does human thrombospondin. The thrombospondin gene has been localized on human chromosome 15. These results demonstrate a function for the ubiquitous adhesive glycoprotein thrombospondin that is likely to be important in the normal physiological down-regulation of neovascularization. In addition, they raise the possibility that thrombospondin may be one of a number of target molecules through which a tumor suppressor gene could act to restrain tumor growth.

Journal ArticleDOI
TL;DR: The data strongly support the use of more extensive initial surgery in class I and II patients with tumors more than 1 cm in size as well as postoperative radioactive 131I ablation of thyroid remnant tissue.
Abstract: We have analyzed the course of papillary thyroid carcinoma in 269 patients managed at the University of Chicago, with an average follow-up period of 12 yr from the time of diagnosis. Patients were categorized by clinical class; I, with intrathyroidal disease; II, with cervical nodal metastases; III, with extrathyroidal invasion; and IV, with distant metastases. Half of the patients had a history of thyroid enlargement known, on the average, for over 3 yr. In 15% of patients given thyroid hormone, the mass decreased in size. The peak incidence of cancer was when subjects were between 20–40 yr of age. Tumors averaged 2.4 cm in size; 21.6% had tumor capsule invasion, and 46% of patients had multifocal tumors. Sixty-six percent of the patients had near-total or total thyroidectomy. The overall incidence of postoperative hypoparathyroidism was 8.4%, but the incidence was zero in 83 near-total or total thyroidectomies carried out by 1 surgeon. Twenty-five percent of the patients had continuing or recurrent dise...

Journal ArticleDOI
TL;DR: In this paper, the authors investigated the convergence of stochastic difference equations (e.g., ARCH) to stochastically differential equations as the length of the discrete time intervals between observations goes to zero, and developed a class of diffusion approximations based on the exponential ARCH model.

Journal ArticleDOI
TL;DR: This chapter shows how the theory of stochastic dynamical systems can be used to characterize the equilibria that are most likely to be selected when the evolutionary process is subject to small persistent perturbations, said to be stochastically stable.

Journal ArticleDOI
TL;DR: The authors show positively framed messages, which specify attributes or benefits gained by using a product, to increase the likelihood of persuading a user to buy a product with a positive effect on her decision.
Abstract: Studies examining message framing effects on persuasion have produced mixed results. Some studies show positively framed messages, which specify attributes or benefits gained by using a product, to...

Journal ArticleDOI
TL;DR: Different functional regions of the NTS/area postrema complex and medullary reticular formation were found to innervate largely nonoverlapping zones in the PB.
Abstract: We examined the subnuclear organization of projections to the parabrachial nucleus (PB) from the nucleus of the solitary tract (NTS), area postrema, and medullary reticular formation in the rat by using the anterograde and retrograde transport of wheat germ agglutinin-horseradish peroxidase conjugate and anterograde tracing with Phaseolus vulgaris-leucoagglutinin. Different functional regions of the NTS/area postrema complex and medullary reticular formation were found to innervate largely nonoverlapping zones in the PB. The general visceral part of the NTS, including the medial, parvicellular, intermediate, and commissural NTS subnuclei and the core of the area postrema, projects to restricted terminal zones in the inner portion of the external lateral PB, the central and dorsal lateral PB subnuclei, and the "waist" area. The dorsomedial NTS subnucleus and the rim of the area postrema specifically innervate the outer portion of the external lateral PB subnucleus. In addition, the medial NTS innervates the caudal lateral part of the external medial PB subnucleus. The respiratory part of the NTS, comprising the ventrolateral, intermediate, and caudal commissural subnuclei, is reciprocally connected with the Kolliker-Fuse nucleus, and with the far lateral parts of the dorsal and central lateral PB subnuclei. There is also a patchy projection to the caudal lateral part of the external medial PB subnucleus from the ventrolateral NTS. The rostral, gustatory part of the NTS projects mainly to the caudal medial parts of the PB complex, including the "waist" area, as well as more rostrally to parts of the medial, external medial, ventral, and central lateral PB subnuclei. The connections of different portions of the medullary reticular formation with the PB complex reflect the same patterns of organization, but are reciprocal. The periambiguus region is reciprocally connected with the same PB subnuclei as the ventrolateral NTS; the rostral ventrolateral reticular nucleus with the same PB subnuclei as both the ventrolateral (respiratory) and medial (general visceral) NTS; and the parvicellular reticular area, adjacent to the rostral NTS, with parts of the central and ventral lateral and the medial PB subnuclei that also receive rostral (gustatory) NTS input. In addition, the rostral ventrolateral reticular nucleus and the parvicellular reticular formation have more extensive connections with parts of the rostral PB and the subjacent reticular formation that receive little if any NTS input. The PB contains a series of topographically complex terminal domains reflecting the functional organization of its afferent sources in the NTS and medullary reticular formation.

Journal ArticleDOI
R Gomer1
TL;DR: The theory of diffusion and the principal methods of determining surface diffusion coefficients are presented and their strengths and weaknesses discussed and areas of agreement and disagreement between various measurements are discussed.
Abstract: The theory of diffusion and the principal methods of determining surface diffusion coefficients are presented and their strengths and weaknesses discussed. A summary of major experimental results for diffusion of metallic and non-metallic adsorbates on metal surfaces is given and areas of agreement and disagreement between various measurements are discussed. A brief overview of principal conclusions, problem areas and future directions concludes the review.

Journal ArticleDOI
TL;DR: The isolation and characterization of cDNAs and genes for these glucose transporters will facilitate studies of their role in the pathogenesis of disorders characterized by abnormal glucose transport, including diabetes mellitus, the glucose-galactose malabsorption syndrome, and benign renal glycosuria.
Abstract: The oxidation of glucose represents a major source of metabolic energy for mammaliancells However, because the plasma membrane is impermeable to polar molecules such as glucose, the cellular uptake of this important nutrient is accomplished by membrane-associated carrier proteins that bind and transfer it across the lipid bilayer Two classes of glucose carriers have been described in mammalian cells: the Na+-glucose cotransporter and the facilitative glucose transporter The Na+-glucose cotransporter transports glucose against its concentration gradient by coupling its uptake with the uptake of Na+ that is being transported down its concentration gradient Facilitative glucose c rriers accelerate the transport of glucose down its concentration gradient by facilitative diffusion, a form of passive transport cDNAs have been isolated from human tissues encoding a Na+-glucose-cotransporter protein and five functional facilitative glucosetransporter isoforms The Na+-glucose cotransporter is expressed by absorptive epithelial cells of the small intestine and is involved in the dietary uptake of glucose The same or a related protein may be responsible for the reabsorption of glucose by the kidney Facilitative glucose carriers are expressed by most if not all cells The facilitative glucose-transporter isoforms have distinct tissue distributions and biochemical properties and contribute to the precise disposal of glucose under varying physiological conditions The GLUT1 (erythrocyte) and GLUT3 (brain) facilitative glucose-transporter isoforms may be responsible for basal or constitutive glucose uptake The GLUT2 (liver) isoform mediates the bidirectional transport of glucose by the hepatocyte and is responsible, at least in part, for the movement of glucose out of absorptive epithelial cells into the circulation in the small intestine and kidney This isoform may also comprise part of the glucosesensing mechanism of the insulin-producing β-cell The subcellular localization of the GLUT4 (muscle/fat) isoform changes in response to insulin, and this isoform is responsible for most of the insulin-stimulated uptake of glucose that occurs in muscle and adipose tissue The GLLJT5 (small intestine) facilitative glucose-transporter isoform is expressed at highest levels in the small intestine and may be involved in the transcellular transport of glucose by absorptive epithelial cells The exon-intron organizations of the human GLUT1 , GLUT2 , and GLUT4 genes have been determined In addition, the chromosomal locations of the genes encoding the Na+-dependent and facilitative glucose carriers have been determined Restriction-fragment-length polymorphisms have also been identified at several of these loci The isolation and characterization of cDNAs and genes for these glucose transporters will facilitate studies of their role in the pathogenesis of disorders characterized by abnormal glucose transport, including diabetes mellitus, the glucose-galactose malabsorption syndrome, and benign renal glycosuria

Journal ArticleDOI
18 Oct 1990-Nature
TL;DR: Evidence is presented that the candidate cDNA is the murine homologue of bovine phosphodiesterase β cDNA and that the mouse rd locus encodes the rod photoreceptor cGMP-phosphodiesterases β subunit.
Abstract: MICE homozygous for the rd mutation display hereditary retinal degeneration and the classic rd lines serve as a model for human retinitis pigmentosa1,2. In affected animals the retinal rod photo-receptor cells begin degenerating at about postnatal day 8, and by four weeks no photoreceptors are left3. Degeneration is preceded by accumulation of cyclic GMP in the retina4 and is correlated with deficient activity of the rod photoreceptor cGMP-phospho-diesterase5. We have recently isolated a candidate complementary DNA for the rd gene6 from a mouse retinal library and completed the characterization of cDNAs encoding all subunits of bovine photoreceptor phosphodiesterase7. The candidate cDNA shows strong homo logy with a cDNA encoding the bovine phospho-diesterase β subunit. Here we present evidence that the candidate cDNA is the murine homologue of bovine phosphodiesterase β cDNA. We conclude that the mouse rd locus encodes the rod photoreceptor cGMP-phosphodiesterase β subunit.


Journal ArticleDOI
TL;DR: Using partial wave unitarity and the observed density of the Universe, it is show that a stable elementary particle which was once in thermal equilibrium cannot have a mass greater than 340 TeV.
Abstract: Using partial wave unitarity and the observed density of the Universe, it is show that a stable elementary particle which was once in thermal equilibrium cannot have a mass greater than 340 TeV. An extended object which was once in thermal equilibrium cannot have a radius less than 7.5 x 10(exp -7) fm. A lower limit to the relic abundance of such particles is also found.

Journal ArticleDOI
30 Nov 1990-Science
TL;DR: Inasmuch as the product of the gamma 134.5 gene extended the host range of the virus by enabling it to replicate and destroy brain cells, it is a viral neurovirulence factor.
Abstract: The gene designated gamma 134.5 maps in the inverted repeats flanking the long unique sequence of herpes simplex virus-1 (HSV-1) DNA, and therefore it is present in two copies per genome. This gene is not essential for viral growth in cell culture. Four recombinant viruses were genetically engineered to test the function of this gene. These were (i) a virus from which both copies of the gene were deleted, (ii) a virus containing a stop codon in both copies of the gene, (iii) a virus containing after the first codon an insert encoding a 16-amino acid epitope known to react with a specific monoclonal antibody, and (iv) a virus in which the deleted sequences were restored. The viruses from which the gene was deleted or which carried stop codons were avirulent on intracerebral inoculation of mice. The virus with the gene tagged by the sequence encoding the epitope was moderately virulent, whereas the restored virus reacquired the phenotype of the parent virus. Significant amounts of virus were recovered only from brains of animals inoculated with virulent viruses. Inasmuch as the product of the gamma 134.5 gene extended the host range of the virus by enabling it to replicate and destroy brain cells, it is a viral neurovirulence factor.

Journal ArticleDOI
TL;DR: This paper examined the relation between a company's performance and its top executives' service on other boards of directors and found that top executives of companies that reduce their dividends are approximately 50% less likely to receive additional outside directorships than are top executives that do not reduce their dividend (significant at 1% level).

Journal ArticleDOI
TL;DR: It is necessary that the Universe possess a nonzero value of B\ensuremath{-}L prior to the epoch of fermion-number violation if baryon and lepton asymmetries are to survive.
Abstract: In the presence of rapid fermion-number violation due to nonperturbative electroweak effects certain relations between the baryon number of the Universe and the lepton numbers of the Universe are predicted. In some cases the electron-neutrino asymmetry is exactly specified in terms of the baryon asymmetry. Without introducing new particles, beyond the usual quarks and leptons, it is necessary that the Universe possess a nonzero value of B - L prior to the epoch of fermion-number violation if baryon and lepton asymmetries are to survive. Contrary to intuition, even though electroweak processes violate B + L, a nonzero value of B + L persists after the epoch of rapid fermion-number violation. If the standard model is extended to include lepton-number violation, for example through Majorana neutrino masses, then electroweak processes will reduce the baryon number to zero even in the presence of an initial B - L unless 20 M(sub L) approximately greater than the square root of (T(sub B - L) m(sub P1)) where M(sub L) sets the scale of lepton number violation and T(sub B - L) is the temperature at which a B - L asymmetry is produced. In many models this implies that neutrinos must be so light that they cannot contribute appreciably to the mass density of the Universe.

Journal ArticleDOI
C G Brilla1, Ruth Pick1, L B Tan1, Joseph S. Janicki1, Karl T. Weber1 
TL;DR: In experimental arterial hypertension in the rat, myocyte and nonmyocyte compartments of the myocardium are under separate controls: myocyte hypertrophy is most closely related to ventricular loading while circulating AII and AL, acting alone or in concert with other humoral factors, regulate the accumulation of collagen within the right and left ventricles.
Abstract: Pathological left ventricular hypertrophy in renovascular hypertension is associated with the accumulation of fibrillar collagen within the extracellular space and around intramyocardial coronary arteries. Even though the angiotensin converting enzyme inhibitor captopril was previously found to attenuate this interstitial and perivascular fibrosis, the relative importance of arterial and ventricular systolic pressures versus circulating angiotensin II (AII) and aldosterone (AL) in promoting hypertrophy and collagen accumulation in renovascular hypertension is uncertain. By drawing on the in-parallel arrangement of the right and left ventricles, with respect to their coronary circulation, and the in-series mechanical alignment of the ventricles, with a pressure-overloaded left and a normotensive right ventricle, this study sought to address this uncertainty. Three models of experimental hypertension, each having a different circulating AII and AL profile, were examined and compared with their controls: renovascular hypertension, where both AII and AL are increased; infrarenal aorta banding, where AII and AL are normal; and a chronic infusion of AL, where AII is suppressed or normal and AL is increased. In renovascular hypertension, as well as with AL, we found a significant rise in the interstitial collagen volume fraction and perivascular collagen area of the pressure-overloaded, hypertrophied left ventricle as well as the normotensive, nonhypertrophied right ventricle. This remodeling was not seen in either ventricle with infrarenal aorta banding despite comparable systemic hypertension and left ventricular hypertrophy. Thus, in experimental arterial hypertension in the rat, myocyte and nonmyocyte compartments of the myocardium are under separate controls: myocyte hypertrophy is most closely related to ventricular loading while circulating AII and AL, acting alone or in concert with other humoral factors, regulate the accumulation of collagen within the right and left ventricles.