Organization of inputs from cingulate motor areas to basal ganglia in macaque monkey

The cingulate motor areas reside within regions lining the cingulate sulcus and are divided into rostral and caudal parts. Recent studies suggest that the rostral and caudal cingulate motor areas participate in distinct aspects of motor function: the former plays a role in higher-order cognitive control of movements, whereas the latter is more directly involved in their execution. Here, we investigated the organization of cingulate motor areas inputs to the basal ganglia in the macaque monkey. Identified forelimb representations of the rostral and caudal cingulate motor areas were injected with different anterograde tracers and the distribution patterns of labelled terminals were analysed in the striatum and the subthalamic nucleus. Corticostriatal inputs from the rostral and caudal cingulate motor areas were located within the rostral striatum, with the highest density in the striatal cell bridges and the ventrolateral portions of the putamen, respectively. There was no substantial overlap between these input zones. Similarly, a certain segregation of input zones from the rostral and caudal cingulate motor areas occurred along the mediolateral axis of the subthalamic nucleus. It has also been revealed that corticostriatal and corticosubthalamic input zones from the rostral cingulate motor area considerably overlapped those from the presupplementary motor area, while the input zones from the caudal cingulate motor area displayed a large overlap with those from the primary motor cortex. The present results indicate that a parallel design underlies motor information processing in the cortico-basal ganglia loop derived from the rostral and caudal cingulate motor areas.

Prostaglandin I(2)/E(2) ratios in unilateral renovascular hypertension of different severities

Differences between prostaglandins I(2) and E(2) in their renal synthesis and pathophysiological roles were investigated in unilateral renovascular hypertension of different severities in 18 patients: 6 with mild stenosis (<75% of the diameter) of the renal artery, 7 with moderate stenosis (75% to 90%), and 5 with severe stenosis (>90%). Before and after aspirin administration (10 mg/kg), renal venous and aortic plasma was assayed for 6-ketoprostaglandin F(1alpha) (instead of prostaglandin I(2)), prostaglandin E(2), and renin activity. In mild or moderate stenosis, the mean 6-ketoprostaglandin F(1alpha) level in renal venous plasma from the stenotic side was not different from that from the normal side or from aortic plasma. Prostaglandin E(2) levels and renin activity in such patients were higher on the stenotic side than on the normal side and higher in venous than in aortic plasma. Aspirin inhibited prostaglandin E(2) synthesis and suppressed renin release from stenotic kidneys and lowered blood pressure as the renin activity decreased in patients with mild or moderate stenosis. In severe stenosis, levels of 6-ketoprostaglandin F(1alpha) and prostaglandin E(2) were higher on the stenotic side than on the normal side and higher in venous than in aortic plasma. Aspirin inhibited the synthesis of both prostaglandins and suppressed renin release from the stenotic kidney. In patients with unilateral renovascular hypertension with mild or moderate stenosis of the renal artery, prostaglandin E(2), rather than I(2), seems to contribute to further acceleration of renin release. Prostaglandin I(2) may increase and participate in further renin release when the stenosis is severe.

Sodium sensitivity of blood pressure appearing before hypertension and related to histological damage in immunoglobulin a nephropathy

Patients with renal parenchymal disease exhibit sodium-sensitive hypertension. We examined patients with immunoglobulin A (IgA) nephropathy to determine whether this sensitivity appears before hypertension begins and whether this sensitivity is related to histological damage. Thirty-eight patients with IgA nephropathy followed a diet with an ordinary sodium level for 1 week and a sodium-restricted diet for 1 week, in random order, and were divided into 3 groups by their systemic blood pressure on the diet with an ordinary sodium level (optimal, <120/<80 mm Hg, n=15; normal to high-normal, 120 to 139/80 to 89 mm Hg, n=18; hypertensive, >/=140/>/=90 mm Hg, n=5). The sodium sensitivity index was calculated as the reciprocal of the slope of the pressure-natriuresis curve drawn by linkage of 2 datum points obtained during the different diets. The scores for glomerulosclerosis and tubulointerstitial damage were evaluated semiquantitatively. The sensitivity index, glomerulosclerosis score, and score for tubulointerstitial damage were higher in patients with normal to high-normal blood pressure or hypertension than in patients with optimal pressure. The sensitivity index was significantly correlated with glomerulosclerosis (P=0.001) and tubulointerstitial damage (P=0.002). In patients with normal to high-normal pressure, sodium restriction lowered blood pressure to the optimal range and decreased proteinuria. In patients with IgA nephropathy, sodium sensitivity of blood pressure related to renal histological damage appears before hypertension.

Design of novel zinc finger proteins: towards artificial control of specific gene expression

In this review, we summarize design strategies for generating proteins with desired sequences such as long contiguous base pairs and diverse sequence specificities based on the nature of Cys(2)-His(2) zinc finger proteins. Recent progress towards artificial DNA binding proteins has been achieved by structure-based design processes and by selection strategies. Indeed, a multi-zinc finger protein with an 18 (or 27)-base pair address, and new zinc finger proteins for diverse DNA target sites (TATA-box and p53 binding site) have been created successfully. Such novel zinc finger proteins will probably be useful tools in molecular biology and potentially in human medicine.

Multiconnection of identical zinc finger: implication for DNA binding affinity and unit modulation of the three zinc finger domain

Cys(2)-His(2)-type zinc finger proteins have a tandemly repeated array structure consisting of independent finger modules. They are expected to elevate the DNA binding affinity and specificity by increasing the number of finger modules. To investigate the relation between the number and the DNA binding affinity of the zinc finger, we have designed the two- to four-finger peptides by connecting the central zinc finger (finger 2) of Sp1 with the canonical linker sequence, Thr-Gly-Glu-Lys-Pro. Gel mobility shift assays reveal that the cognate three- and four-finger peptides, Sp1(zf222) and Sp1(zf2222), strongly bind to the predicted target sequences, but the two-finger peptide, Sp1(zf22), does not. Of special interest is the fact that the dissociation constant for Sp1(zf2222) binding to the target DNA is comparable to that for Sp1(zf222). The methylation interference, DNase I and hydroxyl radical footprintings, and circular permutation analyses demonstrate that Sp1(zf2222) binds to its target site with three successive zinc fingers and the binding of the fourth zinc finger is inhibited by DNA bending induced by the binding of the three-finger domain. The present results strongly indicate that the zinc finger protein binds to DNA by the three-finger domain as one binding unit. In addition, this information provides the basis for the design of a novel multifinger protein with high affinity and specificity for long DNA sequences, such as chromosomal DNAs.

Inhibitory effect of baicalein, a flavonoid in Scutellaria Root, on eotaxin production by human dermal fibroblasts

Eotaxin is an eosinophil-specific chemokine associated with the recruitment of eosinophils to sites of allergic inflammation. "Saiboku-to" (Formula magnoliae et bupleuri) is a kampo herbal medicine used for the treatment of bronchial asthma in Japan. In this study, we investigated the effects of Scutellaria Root, a major herb in Saiboku-to and its components such as baicalein and baicalin on eotaxin production by IL-4 plus TNF-alpha-stimulated human fibroblasts. An extract of Scutellaria Root markedly inhibited eotaxin production. Four major flavonoids from Scutellaria Root were found to show inhibitory activity on eotaxin production at a concentration of 10 micrograms/ml in the order of baicalein > oroxylin A > baicalin > skullcapflavon II. The inhibitory effect of baicalein was expressed in a dose-dependent manner, and almost 50% inhibition was observed at 1.8 micrograms/ml. Furthermore, baicalein prevented human eotaxin mRNA expression in IL-4 plus TNF-alpha-stimulated human fibroblasts. These results help explain the pharmacological efficacy of Scutellaria Root in the treatment of bronchial asthma since it would suppress eotaxin associated recruitment of eosinophils.

Immunohistochemical localization of voltage-gated calcium channels in substantia nigra dopamine neurons

The rhythmic firing of dopaminergic (DA) neurons in the substantia nigra pars compacta (SNc) is thought to be mediated by nifedipine-sensitive Ca(2+) channels, although an involvement of omega-conotoxin-sensitive Ca(2+) channels is also suggested. In an attempt to localize such Ca(2+) channels at both the regional and cellular levels, their expression and distribution patterns were immunohistochemically investigated in the rat SNc. The three distinct subtypes of voltage-gated Ca(2+) channels were tested: the class B N-type alpha 1 subunit (CNB1), the class C L-type alpha 1 subunit (CNC1) and the class D L-type alpha 1 subunit (CND1). A large number of SNc neurons showed intense immunoreactivity against CND1 and they were distributed throughout the entire extent. By contrast, many fewer neurons displayed less intense CNC1 immunoreactivity and many of them were located in the lateral aspect of the SNc. No immunoreactivity against CNB1 was detected in the SNc. Moreover, double immunofluorescence analysis in combination with tyrosine hydroxylase staining revealed that virtually all DA neurons were CND1-immunoreactive whereas many DA neurons especially in the medial SNc exhibited only faint or no immunoreactivity against CNC1. Both CNC1 and CND1 were expressed in cell bodies and proximal dendrites of SNc DA neurons, whilst their distal dendrites that penetrated into the substantia nigra pars reticulata expressed CND1 alone. Thus, the ubiquitously and intensely expressed class D alpha 1 subunit of L-type Ca(2+) channels that is sensitive to both nifedipine and omega-conotoxin may be responsible for the pacemaker activity of SNc DA neurons.

Sodium sensitivity related to albuminuria appearing before hypertension in type 2 diabetic patients

OBJECTIVE

To find whether sodium sensitivity of blood pressure appears before hypertension and whether the sensitivity is related to diabetic nephropathy, we examined type 2 diabetic patients with normal levels of serum creatinine.

RESEARCH DESIGN AND METHODS

A total of 32 patients were divided into three age-matched groups: 11 patients had normoalbuminuria, 12 had microalbuminuria, and 9 had macroalbuminuria. Patients stayed on a diet with ordinary sodium levels for 1 week and a sodium-restricted diet for 1 week, in random order. Urinary excretion of sodium and albumin and systemic blood pressure were measured daily. A pressure-natriuresis curve was drawn by linkage of the two datum points obtained in the steady state during the different diets. We calculated the sodium sensitivity index as the reciprocal of the slope of this curve.

RESULTS

The median sodium sensitivity index and the mean blood pressure were higher in micro- and macroalbuminuric patients than in normoalbuminuric patients. Eighteen patients were without hypertension (<140/90 mmHg); of these, 10 had blood pressure readings <130/85 mmHg with ordinary sodium levels. Urinary albumin was correlated with the index but not with blood pressure. For these 10 patients, the index in those with albuminuria was higher than in those with normoalbuminuria. In such patients with albuminuria, sodium restriction decreased albuminuria and blood pressure.

CONCLUSIONS

In type 2 diabetic patients with albuminuria but normal levels of serum creatinine, sodium sensitivity of blood pressure appears before hypertension and is related to albuminuria; sodium restriction is one treatment for diabetic nephropath, even without hypertension.

[Penetrating lung and diaphragmatic injuries with no abnormal finding of chest X-ray: a case report]

A case of penetrating lung and diaphragmatic injuries with no abnormal findings of chest X-ray is reported. A 76-year-old man was admitted to our hospital due to penetrating chest trauma. A simple X-ray film of the chest on admission revealed no abnormal finding. An emergency operation was performed. On exploring the back open wound, we found a laceration of 7 cm in diameter in the right diaphragm and lung laceration. Then we repaired primarily with absorbable material. The postoperative course was uneventful, and the patient was discharged 12 days later. Penetrating truncal traumas can result in diaphragmatic injury. Sometimes the clinical and roentgenographic findings are unreliable. If the diagnosis is missed, a diaphragmatic injury may occur delayed diaphragmatic hernias within hours to years. Accordingly, initial wound exploration are important for the diagnosis of diaphragmatic injury in avoiding serious complications.

Oxidation products of uric acid and ascorbic acid in preterm infants with chronic lung disease

Allantoin, the oxidation product of uric acid (UA), can be used as an in vivo marker of free radical generation. The aims of the present study were to evaluate the allantoin changes in plasma and bronchoalveolar lavage fluid (BALF) as well as to examine plasma levels of ascorbic acid (AA) and its oxidation product, dehydroascorbic acid (DHAA), in infants with or without chronic lung disease (CLD) during the first week of life. The study population was 20 infants of 24-30 weeks gestation, comprising 10 who subsequently developed CLD and 10 without CLD. In the CLD infants, the plasma allantoin/UA ratio showed a significant increase after day 1 and continued to increase gradually to reach a peak on day 6 (6.5 +/- 4.1% for CLD and 2.1 +/- 0.9% for non-CLD infants). The allantoin/UA ratio in BALF was also higher in CLD infants and the difference reached significance on days 4-6 (41.2 +/- 15.8% for CLD and 11.7 +/- 9.9% for non-CLD infants). In contrast to allantoin, the plasma DHAA/AA ratio did not differ between the 2 groups throughout the study period. Our findings that the allantoin/UA ratios were significantly higher in CLD than non-CLD infants not only in plasma but also in BALF, and that the intergroup differences of this ratio in both plasma and BALF was more prominent in the latter half of the first week of life further confirm our previous speculation that oxygen radicals are involved in the development of neonatal CLD.

Inducible expression of a Th2-type CC chemokine thymus- and activation-regulated chemokine by human bronchial epithelial cells

CCR4 is now known to be selectively expressed in Th2 cells. Since the bronchial epithelium is recognized as an important source of mediators fundamental to the manifestation of respiratory allergic inflammation, we studied the expression of two functional ligands for CCR4, i.e., macrophage-derived chemokine (MDC) and thymus- and activation-regulated chemokine (TARC), in bronchial epithelial cells. The bronchial epithelium of asthmatics and normal subjects expressed TARC protein, and the asthmatics showed more intense expression than the normal subjects. On the other hand, MDC expression was only weakly detected in the asthmatics, but the intensity was not significantly different from that of normal subjects. Combination of TNF-alpha and IL-4 induced expression of TARC protein and mRNA in bronchial epithelial A549 cells, which was slightly up-regulated by IFN-gamma. The enhancement by IFN-gamma was more pronounced in bronchial epithelial BEAS-2B cells, and a maximum production occurred with combination of TNF-alpha, IL-4, and IFN-gamma. On the other hand, MDC was essentially not expressed in any of the cultures. Furthermore, expressions of TARC protein and mRNA were almost completely inhibited by glucocorticoids. These results indicate that the airway epithelium represents an important source of TARC, which potentially plays a role via a paracrine mechanism in the development of allergic respiratory diseases. Furthermore, the beneficial effect of inhaled glucocorticoids on asthma may be at least in part due to their direct inhibitory effect on TARC generation by the bronchial epithelium.

[1-11C]Octanoate as a PET tracer for studying ischemic stroke: evaluation in a canine model of thromboembolic stroke with positron emission tomography

Octanoate is taken up by the brain and converted in astrocytes to glutamine through the TCA cycle after beta-oxidation. Consequently, [1-11C]octanoate might serve as a useful positron emission tomography (PET) probe for studying cerebral oxidative metabolism and/or astroglial functions. The present study attempted to evaluate the utility of using [1-11C]octanoate as a PET tracer for imaging and evaluating the pathophysiology of ischemic stroke. We used a canine model of thromboembolic stroke. Five male beagle dogs were implanted with an indwelling catheter in the left internal carotid artery. A single autologous blood clot was injected into the left internal carotid artery through the catheter. The brain distribution of [1-11C]octanoate and cerebral blood flow (CBF) were determined 24 h after insult using a high resolution PET scanner. Post mortem brain regions unstained with 2,3,5-triphenyltetrazolium chloride (TTC) were defined as infarcts. In the region of an infarct, accumulation of [1-11C]octanoate decreased concurrently with CBF reduction. In contrast, normal accumulation of [1-11C]octanoate was observed in ischemic but vital regions, suggesting that an increased accumulation of [1-11C]octanoate relative to CBF takes place in these regions. In conclusion, [1-11C]octanoate accumulated in ischemic but vital regions, indicating that [1-11C]octanoate is a potentially useful PET tracer for imaging and evaluating the pathophysiology of ischemic stroke.

Different patterns of renal prostaglandins I2 and E2 in patients with essential hypertension with low to normal or high renin activity

OBJECTIVE

Differences in renal synthesis between prostaglandins I2 and E2, and the relationships of the amounts synthesized to renin release were investigated in patients with essential hypertension.

METHODS

Of 12 inpatients, six had low to normal plasma renin activity and six had high renin activity. Before and 30 min after intravenous injection of aspirin D,L-lysine (18 mg/kg), abdominal aortic and renal venous plasma was sampled and assayed for renin activity, 6-ketoprostaglandin F1alpha (as an index of prostaglandin I2), and prostaglandin E2.

RESULTS

In patients with low to normal renin activity, mean +/- SD plasma levels of 6-keto-prostaglandin F1alpha were lower in the right and left renal veins (3.6 +/- 1.4 and 4.1 +/- 1.5 pg/ml, respectively) than in the aorta (5.5 +/- 2.0 pg/ml), but in the other patients, the levels in these veins (7.0 +/- 2.4 and 6.5 +/- 1.5 pg/ml) were higher than in the aorta (5.4 +/- 0.9 pg/ml). Plasma prostaglandin E2 levels in both veins were higher than in the aorta in both groups and, at each site, the levels were similar in the two groups. Aspirin suppressed renin release in the patients with high renin activity.

CONCLUSIONS

In patients with essential hypertension with low to normal renin activity, either less prostaglandin I2 than prostaglandin E2 is produced in the kidney or else more is metabolized there, and in such patients with high renin activity, the renal synthesis of prostaglandin I2, more than that of prostaglandin E2, seems to be related to the increased renin release.

Excitatory cortical inputs to pallidal neurons via the subthalamic nucleus in the monkey

How the motor-related cortical areas modulate the activity of the output nuclei of the basal ganglia is an important issue for understanding the mechanisms of motor control by the basal ganglia. In the present study, by using awake monkeys, the polysynaptic effects of electrical stimulation in the forelimb regions of the primary motor and primary somatosensory cortices on the activity of globus pallidus (GP) neurons, especially mediated by the subthalamic nucleus (STN), have been characterized. Cortical stimulation induced an early, short-latency excitation followed by an inhibition and a late excitation in neurons of both the external and internal segments of the GP. It also induced an early, short-latency excitation followed by a late excitation and an inhibition in STN neurons. The early excitation in STN neurons preceded that in GP neurons. Blockade of STN neuronal activity by muscimol (GABA(A) receptor agonist) injection resulted in abolishment of both the early and late excitations evoked in GP neurons by cortical stimulation. At the same time, the spontaneous discharge rate of GP neurons decreased, pauses between the groups of spikes of GP neurons became prominent, and the firing pattern became regular. Injection of (+/-)-3-(2-carboxypiperazin-4-yl)-propyl-1-phosphonic acid (CPP) [N-methyl-D-aspartate (NMDA) receptor antagonist], but not 1,2,3, 4-tetrahydro-6-nitro-2,3-dioxo-benzo[f]quinoxaline-7-sulfonamide disodium [NBQX (non-NMDA receptor antagonist)], into the STN attenuated the early and late excitations in GP neurons, suggesting that cortico-subthalamic transmission is mediated mainly by NMDA receptors. Interference with the pallido-subthalamic transmission by bicuculline (GABA(A) receptor antagonist) injection into the STN made the inhibition distinct without affecting the early excitation. The present results indicate that the cortico-subthalamo-pallidal pathway conveys powerful excitatory effects from the motor-related cortical areas to the GP with shorter conduction time than the effects conveyed through the striatum.

DNA-bending finger: artificial design of 6-zinc finger peptides with polyglycine linker and induction of DNA bending

DNA structural changes such as bending play an important role in various biological reactions. Not only protein binding to its specific DNA sequence but also DNA bending induced by the protein is indispensable for unique gene expression. Therefore, an artificial protein that induces a DNA conformational change is interesting as a transcriptional regulator of a specific gene. We created 6-zinc finger proteins, Sp1ZF6(Gly)n (n = 4, 7, 10), by connecting two DNA binding domains of transcription factor Sp1 with flexible polyglycine peptide linkers, and their effects on DNA structure were compared with that of native 3-zinc finger Sp1(530-623). Gel electrophoretic methods revealed that Sp1ZF6(Gly)7 and Sp1ZF6(Gly)10 bind to two distal GC boxes and result in DNA bending. Evidently, the hydroxyl radical footprinting analysis demonstrated that hypersensitive cleavage was observed at the 5'-TA step in the intervening region bound by Sp1ZF6(Gly)7 or Sp1ZF6(Gly)10. The phasing assays strongly suggested that the induced DNA bending was directed toward the major groove and that Sp1ZF6(Gly)7 caused the most drastic directional change in DNA bending. Of special interest are the facts that the newly designed 6-finger peptides Sp1ZF6(Gly)7 and Sp1ZF6(Gly)10 can induce DNA bending at the intervening region of the two distal binding sites and that the linker length between two 3-zinc finger motifs has a crucial effect on the entire DNA-bending direction. Such DNA-bending fingers may be feasible for use as a gene expression regulator based on the structural change in DNA in the future.

A cortical motor region that represents the cutaneous back muscles in the macaque monkey

A cortical motor region that represented the cutaneous muscles on the back was identified on the medial wall of the frontal lobe in the macaque monkey. In this region, neurons responded to somatosensory stimuli such as light touch or squeezing of the back skin, and intracortical microstimulation elicited contraction of the back skin. Such a region was located primarily on the dorsal bank of the cingulate sulcus, corresponding to the dorsal cingulate motor area.

The inhibitory effect of KT3-671, a nonpeptide angiotensin-receptor antagonist, on rabbit and rat isolate vascular smooth muscles: a possible involvement of K(ATP) channels

The vasoinhibitory effect of KT3-671, a recently synthesized nonpeptide angiotensin II (Ang II), AT1-receptor antagonist, and the factors affecting insurmountable antagonism of Ang II were examined in rabbit and rat isolated vascular smooth muscle preparations. In rabbit and rat aortic rings, KT3-671 caused insurmountable antagonism of Ang II. In addition, KT3-671 inhibited contractile responses to angiotensin III (Ang III). In rabbit isolated smooth muscles, KT3-671 was most effective in reducing the maximal contraction induced by Ang II in the renal artery followed by the basilar artery and the aorta. In rat renal arterial rings, KT3-671 (10(-5) M) inhibited the concentration-response curves of prostaglandin F2alpha and STA2. In rabbit and rat aortic rings without endothelium, the insurmountable antagonisms of Ang II by KT3-671 and EXP 3174 were changed to surmountable antagonism by pretreatment with DuP 753 and KT3-671, respectively. In addition, KT3-671 abolished the inhibitory effect of CV- 11974 in the rat aorta but not in the rabbit aorta. Indomethacin (10(-5) M) or the removal of endothelium did not affect the inhibitory effect of Ang II by CV-11974 or EXP 3174 but enhanced the insurmountable antagonism by KT3-671. ODQ (3 x 10(-6) M), N(G)-nitro-L-arginine (3 x 10(-4) M), 4-aminopyridine (3 x 10(-3) M), tetraethylammonium (TEA; 10(-3) M), or iberiotoxin (10(-7) M) did not affect the inhibitory action of KT3-671 or CV-11974. Methylene blue (3 x 10(-6) M), KCl (10(2) M), TEA (10(-2) M), or BaC12 (10(-4) M) changed the insurmountable antagonism by KT3-671 to surmountable antagonism and abolished the inhibitory effect of CV-11974. However, glibenclamide (3 x 10(-6) M) did not affect the inhibitory action of KT3-671 but reduced the insurmountable antagonism by CV- 11974. These results indicate that KT3-671 is an insurmountable antagonist of Ang II in the rabbit and rat aorta. The results in the rat aorta also suggest that K(ATP) channels may be involved in insurmountable antagonism of Ang II by KT3-671 and CV-11974. Key Words: KT3-671-Rabbit-Rat-Vascular smooth muscle-Angiotensin II-Insurmountable antagonist-K(TP)channels.

[Surgical treatment for spontaneous hemopneumothorax complicated by delayed re-bleeding: a case report]

A 34-year-old man was admitted to the hospital due to spontaneous hemopneumothorax. A chest tube drainage was performed, and hemorrhagic plueral effusion of 1,600 ml was drained. Because of this, the patient was transferred to the emergency center of our hospital. Following a blood transfusion, we continued to treat conservatively for nine days, because no more bleeding was recognized. On day ten, the patient suddenly started bleeding again, thus, an emergency operation was performed. At the operation under a thoracoscope, a bleeding point was ligated with surgical clip, however, it was difficult to remove blood clots that were attached with the lung surface, it was impossible to continue the thoracoscopic surgery. If re-bleeding occurs after the acute phase, problems may arise from conservative treatment. So, early surgical treatment should be considered.

Effects of nitric oxide scavenger, carboxy-PTIO on endotoxin-induced alterations in systemic hemodynamics in rats

The present experiments were conducted to clarify the mode of cardiovascular action of carboxy-2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (carboxy-PTIO), a nitric oxide (NO) scavenger, during rat endotoxic shock by determining cardiac output and systemic arterial tone simultaneously. Lipopolysaccharide (LPS) (10 mg/kg, i.v.) decreased systemic blood pressure and cardiac output with transient increases in hematocrit and total vascular resistance. Administration of carboxy-PTIO (1.7 mg x kg(-1) x min(-1), i.v. for 60 min) at 90 min after LPS attenuated further decline in blood pressure and cardiac output without affecting changes in hematocrit or total vascular resistance. It is concluded that carboxy-PTIO attenuates endotoxin-induced hypotension predominantly by maintaining cardiac output in rat experimental endotoxic shock.

Renal production of thromboxane and prostaglandins in a rat model of type 2 diabetes

In an investigation of the involvement of prostanoids in the pathogenesis of nephropathy in type 2 diabetes, we repeatedly measured the urinary excretion of prostanoids in both diabetic and healthy rats as the rats aged. Seven rats of the Otsuka Long-Evans Tokushima Fatty strain were used as rats with a model of type 2 diabetes and seven rats of the Long-Evans Tokushima Otsuka strain were used as rats without diabetes. Thromboxane (TX) B2 and 6-keto-prostaglandin (PG) F1alpha, the amounts of which reflect renal production of TXA2 and PGI2, respectively, and PGE2 in urine collected in metabolic cages were assayed when rats were 14, 30, 46, and 54 weeks old. Plasma glucose and urinary protein excretion also were measured periodically. The mean plasma glucose concentration of the diabetic rats was higher than that of the healthy rats throughout the study. At 30 weeks and later, urinary protein excretion by the diabetic rats was greater than that of the healthy rats, and it increased with age. Urinary excretion of TXB2 by the diabetic rats was higher than that of the healthy rats at 14 weeks (52.4+/-23.5 vs. 27.0+/-2.6 ng/day; mean +/- SD, P = .015) and the difference continued to the end of the experiment. Urinary excretion of 6-keto-PGF1alpha by the diabetic rats was high at 14 weeks (52.3+/-12.8 vs. 26.9+/-4.6 ng/day; mean +/- SD, P<.001) but decreased with age and was the same as that of the healthy rats at 54 weeks. The urinary excretion of PGE2 by the two groups of rats was not significantly different. These results suggest that altered renal production of TXA2 and PGI2 is involved in the pathogenesis of diabetic nephropathy in rats with type 2 diabetes.

Flow cytometric detection and analysis of tailless sperm caused by sonication or a chemical agent

Flow cytometric analysis has been developed to detect tailless sperm with heads detached from the tails at the neck position. When isolated tailless sperm suspension was subjected to flow cytometry, a second sperm population appeared alongside the normal sperm population on light scatter-histogram. The percentage of this second sperm population (85.2%) was in good agreement with that for the tailless sperm (88.7%) determined microscopically, indicating that the second sperm population would correspond to tailless sperm population in the light scatter-histogram. Rates for tailless sperm determined by flow cytometry significantly correlated with those estimated microscopically following exposure of sperm to either sonication (r = 0.94, P < 0.01), or nitrobenzene (r = 0.80, P < 0.01). The results indicated the utility of the light scatter-histogram in flow cytometry as a simple and convenient procedure for the detection of tailless sperm induced by chemical compounds.

Preliminary evaluation of [1-11C]octanoate as a PET tracer for studying cerebral ischemia: a PET study in rat and canine models of focal cerebral ischemia

Octanoate is taken up into the brain and is converted in astrocytes to glutamine through the TCA cycle after beta-oxidation. We speculate that [1-11C]octanoate may be used as a tracer for astroglial functions and/or fatty acid metabolism in the brain and may be useful for studying cerebral ischemia. In the present study we investigated brain distribution of [1-11C]octanoate and compared it with cerebral blood flow (CBF) by using rat and canine models of middle cerebral artery (MCA) occlusion and a high resolution PET. In rats brain distribution of [15O]H2O measured 1-2 h and 5-6 h after insult was compared with that of [1-11C]octanoate measured 3-4 h after insult. Radioactivity ratios of lesioned to normal hemispheres determined with [15O]H2O were lower than those determined with [1-11C]octanoate. These results were confirmed by a study on a canine model of MCA-occlusion. Twenty-four hours after insult, CBF decreased in the MCA-territory of the occluded hemisphere, whereas normal or higher accumulation of [1-11C]octanoate was observed in the ischemic regions. The uptake of [1-11C]octanoate-derived radioactivity therefore increased relative to CBF in the ischemic regions, indicating that [1-11C]octanoate provides functional information different from CBF. In conclusion, we found that [1-11C]octanoate is a potential radiopharmaceutical for studying the pathophysiology of cerebral ischemia.