Genetic reprogramming with stem cells regenerates glomerular epithelial podocytes in Alport syndrome

Glomerular filtration relies on the type IV collagen (ColIV) network of the glomerular basement membrane, namely, in the triple helical molecules containing the α3, α4, and α5 chains of ColIV. Loss of function mutations in the genes encoding these chains (Col4a3, Col4a4, and Col4a5) is associated with the loss of renal function observed in Alport syndrome (AS). Precise understanding of the cellular basis for the patho-mechanism remains unknown and a specific therapy for this disease does not currently exist. Here, we generated a novel allele for the conditional deletion of Col4a3 in different glomerular cell types in mice. We found that podocytes specifically generate α3 chains in the developing glomerular basement membrane, and that its absence is sufficient to impair glomerular filtration as seen in AS. Next, we show that horizontal gene transfer, enhanced by TGFβ1 and using allogenic bone marrow-derived mesenchymal stem cells and induced pluripotent stem cells, rescues Col4a3 expression and revive kidney function in Col4a3-deficient AS mice. Our proof-of-concept study supports that horizontal gene transfer such as cell fusion enables cell-based therapy in Alport syndrome.

Nutritional Status Association With Sarcopenia in Patients Undergoing Maintenance Hemodialysis Assessed by Nutritional Risk Index

Background

Malnutrition and sarcopenia are frequently observed in patients undergoing maintenance hemodialysis (MHD). To elucidate whether malnutrition is associated with sarcopenia in those cases, the relationship of nutritional status with sarcopenia was investigated.

Methods

Nutritional status was assessed using a nutritional risk index (NRI) developed for patients undergoing MHD. This retrospective cross-sectional study included 315 MHD patients (199 males, 116 females), who were divided into low-risk (score 0–7) and medium-/high-risk (score 8–13) groups. Sarcopenia and severe sarcopenia, along with low muscle mass, low muscle strength, and low physical performance were defined using the Asian Working Group for Sarcopenia 2019 criteria.

Results

The median NRI score was 5.0, while the prevalence of medium-/high-risk cases among the patients was 31.1%. Additionally, the rates of those with low muscle mass, low muscle strength, and low physical performance were 55.9, 60.6, and 31.4%, respectively, while those of sarcopenia and severe sarcopenia were 44.1 and 20.0%, respectively. Multivariable logistic regression analyses revealed a significant (P < 0.001) association of NRI score with sarcopenia [odds ratio (OR) 1.255, 95% confidence interval (CI) 1.143–1.377] and severe sarcopenia (OR 1.257, 95% CI 1.122–1.407), as well as low muscle mass (OR 1.260, 95% CI 1.157–1.374), low muscle strength (OR 1.310, 95% CI 1.178–1.457), and low physical performance (OR 1.216, 95% CI 1.104–1.339). Furthermore, medium-/high-risk status showed a significant (P < 0.05) association with sarcopenia (OR 2.960, 95% CI 1.623–5.401) and severe sarcopenia (OR 2.241, 95% CI 1.151–4.362), as well as low muscle mass (OR 2.141, 95% CI 1.219–3.760), low muscle strength (OR 7.665, 95% CI 3.438–17.091), and low physical performance (OR 2.570, 95% CI 1.401–4.716).

Conclusions

These results suggest that malnutrition contributes to sarcopenia/severe sarcopenia in MHD patients by reducing muscle mass and strength, and physical performance.

Xanthine Oxidoreductase Inhibitor Use Associated With Reduced Risk of Sarcopenia and Severe Sarcopenia in Patients Undergoing Hemodialysis

Background

Xanthine oxidoreductase (XOR) inhibition reduces reactive oxygen species (ROS) production and enhances adenosine triphosphate (ATP) synthesis. We investigated the protective effects of XOR inhibitor treatment on sarcopenia, frequently observed in patients undergoing hemodialysis (HD), in which increased ROS and ATP shortage are known to be involved.

Methods

This retrospective cross-sectional study included 296 HD patient (203 males, 93 females). Muscle mass, physical performance, and muscle strength were assessed using dual-energy X-ray absorptiometry, five-time chair stand testing, and handgrip strength, respectively. The Asian Working Group for Sarcopenia 2019 criteria were used to define low muscle mass, low physical performance, and low muscle strength, as well as sarcopenia and severe sarcopenia.

Results

Sarcopenia and severe sarcopenia prevalence rates were 42.2 and 20.9%, respectively. XOR inhibitor users (n = 119) showed a significantly (p < 0.05) lower prevalence of sarcopenia and severe sarcopenia, as well as reduced muscle mass, physical performance, and muscle strength than non-users (n = 177). Multivariate logistic regression analyses also revealed XOR inhibitor use to be significantly associated with low muscle mass [odds ratio (OR), 0.384; 95% confidence interval (CI), 0.183–0.806; p = 0.011] and low physical performance (OR, 0.286; 95% CI, 0.142–0.578; p < 0.001), while significance with low muscle strength was borderline. Furthermore, XOR inhibitor use was significantly associated with sarcopenia (OR, 0.462; 95% CI, 0.226–0.947; p = 0.035) and severe sarcopenia (OR, 0.236; 95% CI, 0.091–0.614; p = 0.003).

Conclusions

XOR inhibitor use was significantly associated with reduced risk of sarcopenia/severe sarcopenia in HD patients, suggesting that XOR inhibitor treatment has protective effects on sarcopenia in HD patients.

BMP7 Signaling in TGFBR2-Deficient Stromal Cells Provokes Epithelial Carcinogenesis

Deregulated transforming growth factor-β (TGFβ) signaling is a common feature of many epithelial cancers. Deletion of TGFβ receptor type 2 (TGFBR2) in fibroblast specific protein-1 (FSP1)-positive stromal cells induces squamous cell carcinoma in the murine forestomach, implicating fibroblast-derived hepatocyte growth factor (HGF) as the major driver of the epithelium carcinogenesis. Prior to cancer development, hyperproliferative FSP1⁺ fibroblasts lacking TGFBR2 accumulate in the forestomach, disrupting the regulatory signaling cross-talk with the forestomach epithelium. Here, concurrent loss in TGFBR2 and SMAD4 completely abrogates the development of forestomach cancer. Bone morphogenic protein-7 (BMP7) was highly upregulated in forestomach cancer tissue, activating Smad1/5/8 signaling, cell proliferation, and HGF production in TGFBR2-deficient FSP1⁺ fibroblasts. This stimulation by BMP7 was lost in the combined TGFBR2 and SMAD4 double knockout fibroblasts, which included a profound decrease in HGF expression. Thus, Smad4-mediated signaling is required to initiate epithelial carcinogenesis subsequent to TGFBR2 deletion in FSP1⁺ fibroblasts.Implications: These findings reveal a complex cross-talk between epithelial cells and the stroma, wherein Smad4 is required to elicit squamous cell carcinomas in the forestomach of mice with TGFBR2-deficient stromal cells. Mol Cancer Res; 16(10); 1568-78. ©2018 AACR.

Endothelial-mesenchymal transition as a novel mechanism for generating myofibroblasts during diabetic nephropathy

This Commentary provides perspective on epithelial-mesenchymal transition in diabetic nephropathy.

Different risk factors for vascular calcification in end-stage renal disease between diabetics and nondiabetics: the respective importance of glycemic and phosphate control

Vascular calcification is highly prevalent in dialysis patients, and significantly increases cardiovascular mortality. The presence and progression of vascular calcification is significantly associated with chronic inflammation and malnutrition. Disorders of mineral metabolism, particularly hyperphosphatemia, have been emphasized as risk factors for vascular calcification. Although vascular calcification has been reported to be highly prevalent in diabetic patients with end-stage renal disease (ESRD), the risk factors for vascular calcification in these patients have not been fully explored. Through a review of the literature and our recent studies examining vascular calcification in ESRD patients, hyperphosphatemia is significantly associated with vascular calcification in nondiabetic ESRD patients, while it may not be a significant risk factor for vascular calcification in diabetic ESRD patients. In diabetic patients, vascular calcification occurs long before the initiation of dialysis therapy, and the factors associated with vascular calcification in non-uremic diabetics appear to be hyperglycemia and related metabolic disorders, such as increased glycation and oxidative stress. In diabetic ESRD patients, hyperglycemia is also suggested to be a significant factor associated with the progression of vascular calcification. Thus, the importance of glycemic and phosphate control is suggested to be emphasized in diabetic and nondiabetic ESRD patients, respectively, for prevention of the progression of vascular calcification.

Receptor for advanced glycation end products is involved in impaired angiogenic response in diabetes

Angiogenic response is impaired in diabetes. Here, we examined the involvement of receptor for advanced glycation end products (RAGE) in diabetes-related impairment of angiogenesis in vivo. Angiogenesis was determined in reconstituted basement membrane protein (matrigel) plugs containing vascular endothelial growth factor (VEGF) implanted into nondiabetic or insulin-deficient diabetic wild-type or RAGE(-/-) mice. The total, endothelial, and smooth muscle (or pericytes) cells in the matrigel were significantly decreased in diabetes, with the regulation dependent on RAGE. In the matrigel, proangiogenic VEGF expression was decreased, while antiangiogenic thrombospondin-1 was upregulated in diabetic mice, regardless of the presence of RAGE. In wild-type mice, proliferating cell nuclear antigen (PCNA)-positive cells in the matrigel were significantly less in diabetic than in nondiabetic mice, while the numbers of transferase-mediated dUTP nick-end labeling (TUNEL)-positive cells were significantly higher. This alteration in PCNA- and TUNEL-positive cells in diabetes was not observed in RAGE(-/-) mice. Similarly, the percentage of nuclear factor kappaB-activated cells is enhanced in diabetes, with the regulation dependent on the presence of RAGE. Importantly, adenovirus-mediated overexpression of endogenous secretory RAGE, a decoy receptor for RAGE, restores diabetes-associated impairment of angiogenic response in vivo. Thus, RAGE appears to be involved in impairment of angiogenesis in diabetes, and blockade of RAGE might be a potential therapeutic target.

[Mechanism of vascular calcification]

Vascular calcification in dialysis patients is associated with morbidity and mortality risks. Recent evidence suggests that vascular calcification is an active process resembling osteogenesis and chondrogenesis process. In this process, hyperphosphatemia is one of the important regulators. Inorganic phosphates directly regulate vascular calcification in vitro through a sodium-dependent phosphate cotransporter and promote expression of the osteoblastic differentiation markers.

Matrix Gla protein is associated with coronary artery calcification as assessed by electron-beam computed tomography

Matrix Gla protein (MGP) is an extracellular matrix protein with wide tissue distribution. It has been demonstrated that the expression of MGP is detected not only in the normal blood vessels but also calcified atherosclerotic plaques, and that MGP deficient mice develop extensive arterial calcification. MGP is thought to be a regulator of vascular calcification. A recent clinical study demonstrates the association between polymorphisms of the MGP gene and increased risk of myocardial infarction. However, there are no reports of the relationship between serum MGP levels and coronary artery calcification (CAC). We evaluated the severity of CAC using electron-beam computed tomography (EBCT), and measured serum MGP levels by enzyme-linked immunosorbent assay in 115 subjects with suspected coronary artery disease. CAC scores were correlated with traditional risk factors, such as age, gender, hyper-tension, diabetes, hyperlipidemia and smoking. The serum MGP levels were lower in patients with CAC than in those without CAC (p<0.001). As the severity of CAC increased, there was a significant decrease in serum MGP levels. Serum MGP levels (U/L) were 116.7 +/- 20.3, 104.9 +/- 19.2, 95.2 +/- 15.2 and 82.2 +/- 19.7, (medians 115.5, 105.0, 94.8, and 81.9) for the subjects with normal (CAC score=0), mild (CAC score=1 to 99), moderate (CAC score=100 to 400), and severe (CAC score >400) coronary calcification, respectively. We found that serum MGP levels are inversely correlated with the severity of CAC. These data suggest a possible role for MGP in the development of vascular calcification.

Statins inhibit in vitro calcification of human vascular smooth muscle cells induced by inflammatory mediators

Although lipid-lowering therapy with 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) decreases the progression of coronary artery and aortic valve calcification, the mechanism of action of these drugs to inhibit the calcification process remains unclear. In this study, we investigated the effect of statins such as cerivastatin and atorvastatin on vascular calcification by utilizing an in vitro model of inflammatory vascular calcification. Cerivastatin and atorvastatin dose-dependently inhibited in vitro calcification of human vascular smooth muscle cells (HVSMCs) induced by the following inflammatory mediators (IM): interferon-gamma, 1alpha,25-dihydroxyvitamin D3, tumor necrosis factor-alpha, and oncostatin M. These statins also depressed expression of alkaline phosphatase (ALP) in HVSMCs induced by these factors. Mevalonate and geranylgeranylpyrophosphate reversed the inhibitory effect of cerivastatin on ALP expression in HVSMCs, while farnesylpyrophosphate showed no effect on the ALP activities inhibited by this drug, suggesting that inhibition of Rho and its downstream target, Rho kinase may mediate the inhibitory effect of cerivastatin. Cerivastatin prevented RhoA activation in HVSMCs induced by the IM. A specific inhibitor of Rho kinase (Y-27632) inhibited in vitro calcification and induction of ALP in HVSMCs. These findings provide a possible mechanism of statins to prevent the progression of calcification in inflammatory vascular diseases such as atherosclerosis and cardiac valvular calcification.

Arterial wall stiffness is associated with peripheral circulation in patients with type 2 diabetes

The prevalence of peripheral vascular disease (PVD) in diabetic patients is manyfold higher than that of age- and sex-matched nondiabetic subjects. This study was designed to evaluate the relationship between quantitatively determined peripheral circulation in the lower extremities and arterial wall thickness or stiffness in 68 patients with type 2 diabetes. Peripheral circulation during treadmill-exercise was monitored by transcutaneous oxygen tension (TcPO2) and was expressed as percentage of post-exercise TcPO2 adjusted by that of pre-exercise (TcPO2 index). Arterial wall thickness (intima-media thickness; IMT) and stiffness (stiffness beta) were measured by ultrasonography. TcPO2 index was negatively (r=-0.350, P=0.0007) correlated with stiffness beta, not with IMT, of the femoral artery. In patients without insulin therapy (n=52), both fasting plasma insulin concentration (r=-0.323, P=0.0023) and HOMA IR, an insulin resistance index, (r=-0.281, P=0.0084) were negatively correlated with TcPO2 index. Multiple regression analyses showed that association of stiffness beta of the femoral artery or HOMA IR with the TcPO2 index was independent of other factors including age, smoking index, ankle brachial pressure index and IMT of femoral artery. Thus, arterial wall stiffness of femoral artery appears to be a major determinant of peripheral circulation in patients with type 2 diabetes.

A case with fear of emitting body odour resulted in successful treatment with clomipramine

A patient with fear of emitting body odour of about 20 years' duration is reported. The patient was improved with clomipramine, a tricyclic antidepressant. Generally in Japan, he would be classified as having anthropophobia. However, according to the criteria advocated by Munro and Chmara (1982), he could be classified as having monosymptomatic hypochondriasis (MH). There are some reports that antidepressants have been effective in patients with either anthropophobia or MH. Therefore, a subgroup of patients which respond to antidepressants may exist in these disorders.

Striatal N-methyl-D-aspartate receptors in haloperidol-induced catalepsy

Bilateral ablation of the frontal cortex of rats markedly reduced the catalepsy induced by haloperidol (1 mg/kg i.p.). Similarly, the selective antagonist of N-methyl-D-aspartate (NMDA) receptors, D(-)-2-amino-5-phosphonopentanoic acid (10 micrograms/side), injected bilaterally into the rostral part of the caudate-putamen (CP) reduced haloperidol-induced catalepsy whereas its injection into the intermediate part of the CP was ineffective. The quisqualate receptor antagonist, L-glutamic acid diethyl ester (100 micrograms/side), did not affect haloperidol-induced catalepsy when injected into the rostral part of the CP. On the other hand, NMDA (1 micrograms/side) injected bilaterally into the rostral part of the CP was able to restore haloperidol-induced catalepsy in frontally decorticated rats without any notable cataleptic effect of its own. These findings suggest that a certain degree of tonic stimulatory effect of corticostriatal glutamatergic pathways on NMDA receptors within the rostral part of the CP is a prerequisite for the expression of the cataleptogenic action of haloperidol.

[Characteristics and regulation of 3H-haloperidol binding to rat brain sigma receptors]

Rat brain sigma receptors were labeled by 3H-haloperidol, and the effects of repeated administrations of pentazocine and haloperidol on these binding sites were investigated. On the basis of preliminary experiments, 30 nM spiperone was included in the assay medium in the frontal cortex (to block binding to D2 dopamine and S2 serotonin sites), but not in the hippocampus or cerebellum; the specific binding was defined by inhibition by 30 or 100 microM (+)3-(3-hydroxy)-N-(1-propyl)piperidine. In the brain regions from untreated animals, saturation studies for the specific binding revealed a single population of saturable binding sites; inhibition studies revealed a distinct sigma receptor pharmacology. Fourteen days successive administrations of 7.5 mg/kg of pentazocine induced a significant increase in Kd without affecting Bmax of the binding in the frontal cortex, but not in the cerebellum. Similar treatments with haloperidol (2 or 4 mg/kg) resulted in a significant decrease in Bmax without changes in Kd of the binding in the frontal cortex and hippocampus. However, no effects were observed in the cerebellum. These findings indicate rat brain sigma receptors respond differently to pentazocine and haloperidol, and there are regional differences in the regulatory mechanisms of sigma receptors.

Rat cortical sigma receptors differentially regulated by pentazocine and haloperidol

Repeated administrations of 7.5 mg/kg of pentazocine (for 14 days) resulted in a significant decrease in the affinity of 3H-haloperidol binding to rat cortical sigma receptors without any changes in the maximal number of binding sites (Bmax). On the other hand, similar treatment with haloperidol (2 or 4 mg/kg) induced a dose dependent decrease in the Bmax values without affecting the affinity of the 3H-haloperidol binding. These findings indicate that rat cortical sigma receptors are differentially regulated by pentazocine and haloperidol.

The restorative action of coenzyme Q10 in 2,4-dinitrophenol-depressed electrical and contractile activities of guinea-pig heart

With electrophysiological methods, mechanisms of the restorative action of coenzyme Q10 (CoQ10) in 2,4-dinitrophenol-depressed electrical and mechanical activities of isolated guinea-pig hearts were studied. Isoproterenol (3 X 10(-8) M)-induced action potential and contraction of the heart in 27 mM KCl Tyrode solution were abolished by 6 X 10(-6) M 2,4-dinitrophenol, while the additional application of CoQ10 (50 micrograms/ml) restored both these activities of the heart. This restorative action of CoQ10 was dose related (2 to 50 micrograms/ml) and was inhibited by 10 micrograms/ml 15-hydroperoxyarachidonic acid (15-HPAA) or pretreatment of the animals with indomethacin (5 mg/kg i.v.). When exogenously applied, 200 ng/ml prostacyclin also restored the 2,4-dinitrophenol-depressed electrical and contractile activities of the heart, but this restorative action of prostacyclin was affected neither by 15-HPAA nor by indomethacin pretreatment. These results suggest the possible participation of prostacyclin in the restorative action of CoQ10 in 2,4-dinitrophenol-depressed electrical and mechanical activities of the heart.

Modulation by alpha 2-adrenergic stimulation of IgE-mediated 14C-serotonin release from rat mast cells

The formaldehyde method was used to examine the effects of clonidine and methoxamine on IgE-mediated 14C-serotonin release from rat mast cells in vitro. Clonidine (10(-11) -10(-8) M) caused dose-related enhancement of the mediator release 7 min after the antigen challenge; yohimbine (10(-6) M) blocked this enhancement by clonidine (10(-6) M), but prazosin (10(-6) M) did not. Methoxamine did not enhance this immunological release reaction at concentrations up to 10(-6) M. PGE1 (2 X 10(-8) -2 X 10(-5) M), isoproterenol (10(-10) -10(-8) M), dopamine (4 X 10(-8) -4 X 10(-8) M) and aminophylline (6 X 10(-6) -6 X 10(-4) M) caused dose-related inhibition of this mediator release 1 min after antigen challenge. Clonidine (10(-13) -10(-12) M), but not methoxamine (10(-8) -10(-6) M), reversed dose-dependently this inhibition of mast cells by PGE1 (2 X 10(-6) M), isoproterenol (10(-8) M), dopamine (4 X 10(-6) M); yohimbine (10(-8) M) antagonized this reversing action of clonidine (10(-12) M), but prazosin (10(-10) M) did not. Neither clonidine (10(-14) -10(-11) M) nor methoxamine (10(-8) -10(-6) M) reversed the inhibitory action of aminophylline (2 X 10(-4) M). These results suggests that clonidine enhances IgE-mediated 14C-serotonin release from rat mast cells and also antagonizes the inhibition of mast cells by PGE1, isoproterenol and dopamine, but not by aminophylline in this immunological reaction through alpha 2-adrenergic receptors, and that the inhibition of adenylate cyclase of mast cells is one of the biochemical actions of alpha 2-adrenergic mechanisms.

Interactions of morphine with PGE1, isoproterenol, dopamine and aminophylline in rat mast cells; their effect on IgE-mediated 14C-serotonin release

The formaldehyde method was used to examine the interactions of morphine with PGE1, isoproterenol, dopamine and aminophylline in rat mast cells by their effects on IgE-mediated 14C-serotonin release. PGE1 (2 x 10(-8) -2 x 10(-5) M), isoproterenol (10(-10) -10(-8) M), dopamine (4 x 10(-8) -4 x 10(-6) M) and aminophylline (6 x 10(-6) -6 x 10(-4) M) caused dose-related inhibition of the mediator release 1 min after an antigen challenge, and propranolol (10(-7) M) blocked the inhibition by isoproterenol (10(-8) M) but not that by dopamine (4 x 10(-6) M), while haloperidol (4 x 10(-6) M) blocked that by dopamine (4 x 10(-6) M) but not that by isoproterenol (10(-8) M). Morphine (3 x 10(-7) -3 x 10(-5) M) reversed the inhibitory effects of PGE1 (2 x 10(-6) M), isoproterenol (10(-8) M) and dopamine (4 x 10(-6) M) dose-dependently and stereospecifically; naloxone (2 x 10(-4) M) antagonized these reversing actions of morphine (3 x 10(-5) M). Morphine (10(-6) -10(-4) M) did not reverse the inhibitory action of aminophylline (6 x 10(-4) M). These results suggest that the inhibitory responses of mast cells to PGE1, isoproterenol and dopamine but not to aminophylline in immunological mediator release were reversed by morphine through opioid receptors, and that the inhibition of adenylate cyclase in mast cells is one of the biochemical actions of morphine.

IgE-mediated 14C-serotonin release from passively sensitized rat mast cells: comparative kinetic study with formaldehyde and ice-cold methods

The kinetics of IgE-mediated release of serotonin from passively sensitized rat mast cells in vitro was studied by stopping 14C-serotonin release with the application of formaldehyde fixative or ice-cold mast cell medium (MCM). Antigen dose-release curves of 14C-serotonin and/or histamine were comparable when mediator release was terminated with either formaldehyde at a final concentration of 1% or ice-cold MCM 15 min after antigen challenge. However, the kinetic study of immunological mediator release stopped by formaldehyde showed that the addition of antigen resulted in a progressive increase of released 14C-serotonin for 7 min, the release curve being sigmoidal, whereas the application of ice-cold MCM artificially enhanced 14C-serotonin and histamine release in the first 2 min. The results suggest that stopping IgE-mediated release of 14C-serotonin with formaldehyde is a simple, rapid and accurate method of studying the kinetics of mediator release from mast cells.

IgE-mediated 14C-serotonin release from rat mast cells modulated by morphine and endorphins

The formaldehyde method was used to examine the interaction of PGE1 with morphine, beta-endorphin and Met-enkephalin on rat mast cells by their effects on IgE-mediated 14C-serotonin release. PGE1 (2x10(-8) -2x10(-5) M) caused a dose-related inhibition of the mediator release 1 min after an antigen challenge, and morphine (3x10(-7) -3x10(-5) M) reversed this PGE1 effect dose-dependently and stereospecifically; naloxone (2x10(-4) M) antagonized this action of morphine. Beta-Endorphin (3x10(-7) -10(-5) M) and Met-enkephalin (3x10(-6) -10(-4) M) mimicked this morphine action dose-dependently and were antagonized by naloxone (2x10(-4) M). These results suggest that morphine and endorphins modulate immunological mediator release from rat mast cells through opioid receptors.

Cardiac hypertrophy: its characteristics as a growth process

The causal relation between cardiac function and growth is analyzed in this review article. Three different levels of development are discussed: cytodifferentiation, embryogenesis and postnatal development. The earliest stage of cardiac morphogenesis, that is, the appearance of cell-specific proteins and of spontaneous contractions, appears to be independent of hemodynamic forces. Also, the first major morphologic transformation of the primitive heart, looping, is the intrinsic property of the heart itself. However, at any later stage of life, hemodynamic function in both health and disease is closely coupled to cardiac growth.

Studies on beta-pyridylcarbinol as a precursor of nicotinamide adenine dinucleotide

The major part of orally administered beta-pyridylcarbinol was converted to nicotinic acid in the gastrointestinal tract, whereas that administered intraperitoneally was partially converted to nicotinic acid in the liver. The conversion of this compound to nicotinic acid in both the gastrointestinal tract and liver involved enzymatic processes. The converted nicotinic acid from beta-pyridylcarbinol may play a dominant role in the biological actions of beta-pyridylcarbinol and possibly involves in the synthesis of NAD via Preiss-Handler's pathway.

Effect of 4-hydroxypyrazolo[3,4-d]pyrimidine (allopurinol) administration of growth of Ehrlich tumor cells

Effect of the administration of 4-hydroxypyrazolo([3,4-d]pyrimidine (allopurinol) on the growth of Ehrlich ascites tumor cells was investigated in an in vivo system. Oral administration of allopurinol (0.1% in diet) suppressed the growth of both ascites and solid types of the tumor after the implantation of Ehrlich tumor cells in mice. The inhibitory action depended on the dose but was lost repidly when the administration was interrupted. Possible mechanisms involved in the inhibitory effect of allopurinol on tumor growth were briefly discussed.

Effect of xanthine oxidase inhibitor on myocardial ischemia

The xanthine oxidase inhibitor, 4-hydroxypyrazolo(3,4-d) pyrimidine (HPP), Allopurinol, caused augmentation of myocardial uptake of [3H] hypoxanthine, which was eventually completely incorporated into ATP. The decrease of [32P] orthophosphate incorporation into ATP induced by isoproterenol was restored by HPP administration.