Some mechanical properties of skinned fibres of pregnant human myometrium

The properties of contractile elements and intracellular Ca2+ storage sites of pregnant human myometrium were studied by recording the mechanical responses in skinned (saponin-treated and membrane-permeable) fibres. Calmodulin increased the amplitude of contractions induced by Ca2+ and the Ca2+ sensitivity for contractile elements in small myometrium strips, but PGF2 alpha, PGE2, oxytocin, or cyclic AMP failed to produce similar effects. After accumulation of Ca2+ in intracellular Ca2+ storage sites, 10 mumol/l PGF2 alpha, 10 mumol/l PGE2, 30 mmol/l caffeine, and 20 mumol/l InsP3 (inositol-trisphosphate) produced contractions by releasing Ca2+ from storage sites. However, 20 nmol/l oxytocin had no effects under the same conditions. The InsP3 sensitive Ca2+ store was much larger than those of PGs or caffeine. These results suggest that pregnant human myometrium contracts with low Ca2+ by a calmodulin sensitive system. The data also indicate that direct application of PGF2 alpha, or PGE2 into the cells discharges Ca2+ from Ca2+ storage sites and that oxytocin extricates Ca2+ via a pathway involving InsP3 by activation of phosphoinositide turnover. We suggest that these agents induce added contractile responses due to a Ca2+ release mechanism from store sites in addition to the influx of Ca2+ from the extracellular space.

The vasodilator and secretory effects elicited by sympathetic nerve stimulation in cat submandibular gland

The effects of electrical stimulation of the peripheral cut ends of the ascending cervical sympathetic trunk on vasomotor, particularly vasodilator, response were studied in relation to salivary secretion in the cat submandibular gland. The vasodilator and salivary responses were compared by stimulating the peripheral cut ends of the sympathetic nerve at various intensities (1-8 V), durations (5-60 s) and frequencies (1-100 Hz) using a 2 ms pulse duration. Electrical stimulation of the cervical sympathetic nerves caused vasoconstriction followed by vasodilatation and salivation. There were certain differences in the maximal responses of vasodilatation and salivation during sympathetic stimulation. For example, optimal frequencies for vasodilatation and salivation were 10 Hz and 20 Hz, respectively. Time-dependent increases in vasodilatation and salivary secretion were seen for periods of up to 30 s and 60 s, respectively. The volume of salivation was not necessarily correlated with the magnitude of vasodilator response. Prior treatment with an alpha-adrenoceptor blocking agent phentolamine largely reduced vasoconstriction (P < 0.01) and almost completely abolished salivary secretion (P < 0.01), but had only a slight inhibitory effect on vasodilatation (0.1 < P < 0.05). Propranolol (a beta-adrenoceptor blocking agent) pretreatment significantly decreased vasodilatation (P < 0.05) but had no statistically significant effect on vasoconstriction or salivation. Scopolamine (a muscarinic cholinoceptor blocking agent) had no effect on the responses followed by sympathetic nerve stimulation but abolished the vagal mediated reflex salivation, indicating that the salivation, but not vasodilatation, elicited by activation of the afferent fibers of the vagus nerve is mediated via parasympathetic muscarinic fibers.(ABSTRACT TRUNCATED AT 250 WORDS)

[Cause of hypotension during spinal anesthesia--the relation between the level of anesthesia and the hypotension]

A retrospective study was conducted on the cause of hypotension during spinal anesthesia and also on the relation between the level of anesthesia and the hypotension. Two hundred twenty three patients who had received spinal anesthesia for gynecological surgery were divided into two groups. Group I consisted of 87 patients with a significant decrease in blood pressure, while group II consisted of 136 patients with no significant decrease in blood pressure. First, the age, dosage of spinal anesthesia, amount of preoperative transfusion, and level of spinal anesthesia were reviewed and compared between the group I and II. Next, all the patients were classified by the level of spinal anesthesia, and the degree of decrease in blood pressure and the frequency of a significant decrease in blood pressure were examined by each level of spinal anesthesia. Only the level of spinal anesthesia was found to differ significantly between the group I and II. The degree of hypotension was greater at higher levels of spinal anesthesia. More than 50% of the patients with T5 or higher levels of anesthesia had a significant decrease in blood pressure. We conclude that the cause of the significant decrease in blood pressure during high spinal anesthesia is in most part due to the blockade of the cardiac sympathetic nerve.

The parasympathetic vasodilator fibers in the trigeminal portion of the distal lingual nerve in the cat tongue

Electrical stimulation of the peripheral and central cut ends of the chorda tympani nerve (CTN) caused an increase in ipsilateral tongue blood flow in anesthetized cats. Both blood flow increases were markedly reduced by pretreatment with the autonomic ganglionic blocker hexamethonium (1.0 mg/kg). Electrical stimulation of the central cut ends of the CTN, inferior alveolar nerve, and vagus nerve as well as of the upper buccal gingiva also caused the vasodilator responses in the sympathectomized cat tongue. These vasodilatations were notably reduced by hexamethonium pretreatment, and were almost completely abolished by the section of the distal lingual nerve (DLN) and the lingual nerve proper but not by section of the CTN. The present data suggest that the parasympathetic vasodilator fibers in the CTN are not involved in somatoautonomic reflex vasodilatation in the cat tongue and that the major part of the somatoautonomic reflex vasodilator response is mediated by parasympathetic fibers running together with the trigeminal portion of the DLN as vasodilator fibers in the cat tongue. This also implies that there are two groups of parasympathetic vasodilator fibers, that is, one originates from the CTN (the facial nerve) and other from the trigeminal portion of the DLN (probably via the glossopharyngeal nerve).

[A case of intermittent Wolff-Parkinson-White syndrome caused by high spinal anesthesia]

We experienced a case of intermittent Wolff-Parkinson-White (WPW) syndrome following spinal anesthesia. This patient had neither any past history of cardiac symptoms nor any abnormal finding in the preoperative electrocardiogram. Soon after spinal anesthesia, the level of anesthesia spread to C6. Both abbreviated PR intervals and delta waves characteristic of WPW syndrome appeared on the electrocardiogram monitor. These abnormal wave-forms continued throughout the operation, but disappeared after three days. This case was diagnosed as intermittent WPW syndrome based upon these observations. High spinal anesthesia effectively blocks the cardiac sympathetic nerve and suppresses the normal atrioventricular conduction. Further, conduction by the accessory pathway is facilitated by the relative excitement of parasympathetic nerve. In the present case, the conduction by the accessory pathway, which had originally been very poor, was transiently promoted by the above-mentioned mechanism, and abnormal wave-forms characteristic of WPW syndrome appeared temporarily in the electrocardiogram.

Cardiovascular effects of KRN2391 in anesthetized dogs: a comparison with cromakalim and nitroglycerin

The cardiovascular effects of KRN2391, N-cyano-N'-(2-nitroxyethyl)-3-pyridine carboximidamide monomethanesulfonate, were compared with those of cromakalim and nitroglycerin in anesthetized dogs. KRN2391 (3-30 micrograms/kg, i.v.), cromakalim (3-30 micrograms/kg, i.v.) and nitroglycerin (1-10 micrograms/kg, i.v.) produced a dose-related decrease of the mean blood pressure with concomitant increase in heart rate. The increase in heart rate caused by cromakalim was lower than that caused by KRN2391 and nitroglycerin. Left ventricular end-diastolic pressure was decreased by all doses of KRN2391 and nitroglycerin. Cromakalim at 3 and 10 micrograms/kg decreased this end-diastolic pressure but increased it at 30 micrograms/kg. Left ventricular dP/dt was increased by KRN2391 and nitroglycerin but was decreased by cromakalim. KRN2391 and cromakalim produced a dose-dependent increase in aortic and coronary blood flow. Nitroglycerin showed biphasic changes in aortic and coronary blood flow, i.e., an initial increase followed by a decrease. At equipotent hypotensive doses, the increase in coronary blood flow induced by KRN2391 was greater than that by cromakalim and nitroglycerin, and total peripheral and coronary vascular resistances were decreased by KRN2391 and cromakalim. Nitroglycerin showed biphasic changes in total peripheral and coronary vascular resistances, i.e., these resistance showed an initial decrease followed by an increase. The relative decrease of coronary vascular resistance compared to the total peripheral vascular resistance was greater for KRN2391 than for cromakalim and nitroglycerin. The changes in hemodynamic parameters caused by KRN2391 were inhibited by pretreatment with glibenclamide (5 mg/kg, i.v.). These results suggest that the hemodynamic profile of KRN2391 is closer to that of cromakalim than to that of nitroglycerin, but that the selectivity for the coronary vascular bed is higher for KRN2391 than for cromakalim. In addition, it is considered that, compared with KRN2391 and nitroglycerin, cromakalim has a low selectivity for the vasculature vs the myocardium.

Comparison of coronary dilating effects of Ki1769, a new K channel opener of the pyridinecarboximidamide type, and nifedipine in anesthetized dogs

The coronary dilating effect of a new type of K channel opener, N-cyano-N'-(2-phenethyl)-3-pyridinecarboximidamide (Ki1769), was examined in anesthetized dogs in comparison with that of nifedipine. Administration of Ki1769 (30 and 100 micrograms/kg, i.v.) and nifedipine (1 and 3 micrograms/kg, i.v.) produced a dose-dependent decrease of mean blood pressure with a concomitant increase in heart rate. Ki1769 and nifedipine dose-dependently increased coronary blood flow and aortic blood flow and decreased coronary vascular resistance and total peripheral vascular resistance. The percentage decrease of coronary vascular resistance was greater than that of total peripheral vascular resistance with Ki1769 and nifedipine, but Ki1769 showed a greater specificity in the decrease of coronary vascular resistance than nifedipine. Glibenclamide (5 mg/kg, i.v.) inhibited these hemodynamic effects of Ki1769 but did not affect those of nifedipine. These results suggest that the preferential effect of Ki1769 on the coronary vascular bed is greater than that of nifedipine. Such a profile of Ki1769 is based on its K channel-opening action.

Gestational changes in endothelium-dependent vasorelaxation in human umbilical artery

OBJECTIVE

We intended to clarify whether (1) the amount of endothelium-derived vasorelaxing factor or nitric oxide released by histamine is sufficient to cause relaxation in human umbilical artery at different stages of gestation and (2) the functional role of endothelium-derived relaxing factor changes with the progress of gestation.

STUDY DESIGN

By means of a bioassay cascade technique with very thin muscle strips, which allows rapid diffusional access of applied drugs (of the order of a few seconds), contractile properties were examined.

RESULTS

At 18 to 22 weeks of gestation histamine produced only a minor contraction, but as gestation progressed the contractile responses increased. L-NG-nitro-arginine greatly enhanced the histamine-induced contractions. Histamine produced a concentration-dependent relaxation during the maintained contraction induced by 39 mmol/L K+ in tissues from 18 to 22 weeks or 30 to 32 weeks but not 38 to 41 weeks of gestation. Thus the concentration-relaxation relationship for histamine showed decreased sensitivity during gestation. The histamine-induced relaxation was enhanced by superoxide dismutase and completely blocked by L-NG-nitro-arginine or mepyramine (H1 antagonist). The concentration-relaxation relationship for the action of glycerol trinitrate relaxation decreased as gestation progressed. In a bioassay cascade an endothelium-intact umbilical artery from 18 to 22 or 38 to 41 weeks of gestation was used as a "donor" and L-NG-nitro-arginine-treated umbilical artery from 18 to 22 and 38 to 41 weeks as a "detector." In the presence of histamine the perfusate that had passed through a donor from 18 to 22 weeks (but not 38 to 41 weeks) attenuated the high K(+)-induced contraction in the detector only from 18 to 22 weeks.

CONCLUSION

These results suggest that the amount of endothelium-derived relaxing factor and the sensitivity of smooth muscle to endothelium-derived relaxing factor decreased with the progress of gestation.

An L-arginine-nitric oxide-cyclic guanosine monophosphate system exists in the uterus and inhibits contractility during pregnancy

OBJECTIVE

Nitric oxide is synthesized from L-arginine and it causes relaxation of smooth muscle by elevating cyclic guanosine monophosphate levels. We hypothesized that an L-arginine-nitric oxide-cGMP system is present in the uterus and modulates contractility.

STUDY DESIGN

Isometric tension of the uterus was measured in vitro from pregnant rats in response to various agents that modulate nitric oxide-cyclic guanosine monophosphate production or action.

RESULTS

Major findings are as follows: (1) The substrate and a donor of nitric oxide produced uterine relaxation; (2) inhibitors of the nitric oxide-cyclic guanosine monophosphate pathway blocked the relaxation responses; (3) nitric oxide synthase was localized to several uterine cell types; (4) nitric oxide was produced by the uterus during periods when L-arginine was consumed and citrulline levels increased; (5) effects of nitric oxide substrate on relaxation were mimicked by cyclic guanosine monophosphate; (6) nitric oxide-cyclic guanosine monophosphate responses were decreased during delivery; (7) L-arginine responses were increased by progesterone, and antiprogesterone treatment decreased cyclic guanosine monophosphate-induced relaxations.

CONCLUSION

An L-arginine-nitric oxide-cyclic guanosine monophosphate system is present in the uterus and it may regulate relaxation during pregnancy. The inhibitory action of L-arginine and 8-bromo-cyclic guanosine monophosphate was considerably lower during delivery and post partum, indicating that the nitric oxide system may contribute to the maintenance of uterine quiescence during pregnancy, when progesterone levels are elevated, but not during delivery.

Dual afferent pathways of vasodilator reflex induced by lingual stimulation in the cat

We investigated whether two groups of afferent fibers in the combined chorda tympani (CT) and lingual (LN) nerve that emanate from the facial and trigeminal nerves function in the vasodilator reflex in the cat lip. Experiments were conducted on 18 cats weighing 1-3 kg which were anesthetized with pentobarbital sodium (30 mg/kg, i.v.) and artificially ventilated (pancuronium bromide 0.2 mg/kg/h, i.v.). Blood flow changes in the lower lip adjacent to the canine tooth on both sides of the mouth were monitored with a laser Doppler flowmeter. Electrical (0-50 V, 2 ms, 40 Hz, 10 s) and capsaicin (1%) stimulation of the tongue or chorda-lingual nerve after cutting the chorda tympani evoked an increase in blood flow in the ipsilateral lower lip (LN-response). Electrical stimulation of the central cut ends of the chorda tympani nerve also caused an increase in blood flow in the ipsilateral lip (CT-response). Capsaicin application to the CT, however, did not elicit a blood flow increase. Both the LN- and CT-responses of the different afferent fibers were reduced by prior treatment with the autonomic ganglion blocking agent hexamethonium (1 mg/kg, i.v.). Results suggest that capsaicin-insensitive fibers in the chorda tympani branch of the facial nerve, as well as capsaicin-sensitive ones in the lingual branch of the trigeminal nerve, participate as afferents of the parasympathetic vasodilator reflex in cat lip.

Gestational changes in L-arginine-induced relaxation of pregnant rat and human myometrial smooth muscle

OBJECTIVE

We intended to demonstrate the presence of an L-arginine-nitric oxide system in human myometrium and to clarify the mechanisms of action of nitric oxide on rat myometrium during gestation.

STUDY DESIGN

By examining very small myometrial muscle strips (approximately 750 muscle cells), characteristic features of contraction of rat longitudinal muscle at the midstage of gestation (day 16) and during delivery at term were determined.

RESULTS

Spontaneous contractions were significantly different during delivery compared with the midstage of gestation of rat myometrium. L-Arginine relaxed spontaneous and carbachol-induced, but not potassium chloride-evoked, contractions at both stages. However, much higher concentrations of L-arginine were required during delivery, 8-Bromo-cyclic guanosine monophosphate inhibited spontaneous contractions from concentrations of 1 nmol/L in the midstage of gestation and from 0.1 mmol/L during delivery. In human myometrial tissues L-arginine also inhibited contractions during the late stages of gestation.

CONCLUSION

(1) The experimental model is sufficient to compare properties of longitudinal myometrial strips during gestation. (2) In rat and human myometrium an L-arginine-nitric oxide system has an important role in inhibiting uterine contractility and possibly maintaining pregnancy. (3) The relaxing effect of the nitric oxide system is largely because of the voltage-independent action of cyclic guanosine monophosphate systems.

Morphological change and destabilization of beta-actin mRNA by tumor necrosis factor in human microvascular endothelial cells

Tumor necrosis factor-alpha (TNF-alpha) produced morphological changes from a cobblestone-like shape into a spindle shape in human omental microvascular endothelial (HOME) cells and also a drastic rearrangement of actin filaments. Expression of beta-actin gene was diminished in HOME cells treated with TNF-alpha for 24 h. Northern blot analysis of the beta-actin gene demonstrated that the cellular level of beta-actin mRNA was decreased at 6-12 h after exposure to TNF-alpha. However, there appeared to be no changes in cellular mRNA levels of beta-tubulin, fibronectin, laminin B1, laminin B2, and laminin binding protein genes after treatment with TNF-alpha. Nuclear run-on assays showed increased transcription of the low-density lipoprotein receptor gene, but not of the beta-actin gene. These data suggested that the TNF-alpha-induced inhibition of beta-actin gene expression was not due to altered transcription activity. The degradation rates of beta-actin, plasminogen activator inhibitor-1, and epidermal growth factor receptor mRNAs were examined in the presence of actinomycin D. beta-Actin mRNA was found to be specifically destabilized in TNF-alpha-treated HOME cells, while other mRNA species were not. Coadministration of cycloheximide blocked the TNF-alpha-induced degradation of beta-actin mRNA. The TNF-alpha-induced destabilization of beta-actin mRNA and rearrangement of actin filaments are discussed in relation to the morphological changes in human microvascular endothelial cells.

Reflex vasodilatation in the cat lip elicited by stimulation of nasal mucosa by chemical irritants

Local application of capsaicin (threshold dose 150 microM) or nicotine (threshold dose 15 mM) to the nasal mucosa as well as electrical stimulation (threshold intensity 10 V) of the nasal mucosa elicited dose- or intensity-dependent blood flow increases in the ipsilateral lower lips of the anesthetized cats. Pretreatment with 3 mM capsaicin applied locally to the nasal mucosa abolished or reduced the vasodilation in response to capsaicin, nicotine, and ammonia vapor but not to light mechanical or electrical stimulation of the nasal mucosa. The blood flow increases elicited by all above stimuli were greatly reduced by pretreatment with hexamethonium, an autonomic ganglion blocker. These results suggest that stimulation of the nasal mucosa by chemical (capsaicin, nicotine, ammonia), mechanical, or electrical methods elicits the autonomic reflex vasodilatation in the cat lower lips. Furthermore, there seem to be at least two types of afferent fibers in the nasal mucosa of the cats: one type is capsaicin-sensitive fibers, while another type is capsaicin-resistant fibers involved in reflex vasodilatation.

Stimulation of plasmin activity in cultured human fibroblast cells by Porphyromonas endodontalis

1. Plasmin activity in the conditioned medium of Gin-1 cells, a human gingival fibroblast cell line, was stimulated by Porphyromonas endodontalis, a putative pathogen of oral submucous abscesses, in a time- and dose-dependent manner. 2. P. endodontalis stimulated the activity of plasminogen activator in both the conditioned medium and the cell lysate. The plasminogen activator in Gin-1 cells was approx. 50 kDa by zymography. 3. The conditioned medium of Gin-1 cells exposed to P. endodontalis stimulated the conversion of human serum prekallikrein to kallikrein. 4. These results suggested that P. endodontalis stimulates the plasminogen activator-plasmin system in Gin-1 cells, and that activated plasmin plays a role in the progress of periodontal tissue inflammation.

[The relation of vertebral artery blood flow velocity to mean arterial pressure during anesthesia with enflurane or isoflurane]

The relation of vertebral artery blood flow velocity (VABFV) to mean arterial pressure (MAP) during anesthesia with enflurane or isoflurane was examined. The subjects were 17 patients on the knee-chest position. Anesthesia was induced with thiamylal and fentanyl. The patients were placed on the knee-chest position after tracheal intubation. Ventilation was adjusted to maintain a constant level of PaCO2 (30-40 mmHg). The patients were divided into two groups. Anesthesia was maintained with enflurane and 67% N2O in group E (8 patients), or with isoflurane and 67% N2O in group I (9 patients). VABFV was measured with a transcranial Doppler sonography (TCD), and MAP was measured through a radial artery catheter. The mean VABFV and MAP were recorded at five-minute intervals. VABFV was found to change with the change in the MAP for the same degree in both groups. The results suggest that cerebral autoregulation is disturbed during either isoflurane-N2O or enflurane-N2O anesthesia.

[The bulletin of Nariakira Shimazu]

In 1858, the sudden and fatal illness of Nariakira Shimazu, the feudal lord of the Satsuma clan, provoked suspicion as to the cause of his death. Nagahiro Kuroda, the feudal lord of the Fukuoka clan, sent a letter to Munenari Date, the feudal lord of the Uwajima clan, informing the results of his investigation, along with the bulletin on Nariakira written by Hoshu Tsuboi, a clan physician. While the author was emending the texts of the bulletin, he found that there are two series of historical materials; dated in August and dated on July 16th, the day Nariakira expired. After examination of those materials, the author also discovered that some corrections may have been made at the office on the original text of the bulletin for compilation of the Shimazu documents in the Meiji era. In the present communication, the author reports the process of the study and the contents of the bulletin.

Innervation of the cat lip by two groups of parasympathetic vasodilator fibres

1. Electrical stimulation of the peripheral cut ends of the chorda tympani nerve proper (CTNP) and the chorda-lingual nerve (CLN) elicited a blood flow increase in the ipsilateral lower lip, tongue and submandibular gland in a stimulus intensity-dependent manner in anaesthetized cats. 2. Pretreatment with hexamethonium (1.0 mg kg-1, i.v.), an autonomic ganglionic blocker, significantly reduced the CTNP-induced blood flow increases in all of the above three sites as well as the CLN-induced blood flow in the lower lip, but it had no effects on the CLN-induced blood flow increases in the tongue and submandibular gland. 3. The CTNP stimulation-induced lower lip blood flow was not influenced by sectioning the lingual nerve proper, but it was abolished by section of either the CLN or the inferior alveolar nerve (IAN) in the mandibular canal. 4. The lip blood flow increases elicited reflexly by electrical stimulation of the upper gingiva, the central cut ends of the mylohyoid nerve and CLN were not affected by cutting of the CTNP, but were markedly reduced by pretreatment with hexamethonium and abolished by the section of the inferior alveolar nerve just distal to the mylohyoid nerve. These observations imply that the parasympathetic vasodilator fibres involved in trigeminally induced reflex vasodilatation responses do not travel with the CTNP. 5. These results suggest that there is a dual innervation of the cat lower lip by two groups of parasympathetic vasodilator fibres; in one case fibres originating from the facial nerve root are distributed to the lower lip via the CTNP, CLN and IAN and in the other fibres emanating from the glossopharyngeal nerve root project to the lower lip via the mandibular nerve and the IAN.

Prenatal diagnosis of congenital lipoid adrenal hyperplasia

BACKGROUND

There are no published reports of prenatal diagnosis of congenital lipoid adrenal hyperplasia, which is the rarest form of congenital adrenal hyperplasia.

CASE

Congenital lipoid adrenal hyperplasia was diagnosed prenatally based on the existence of one affected sibling in the family, the presence of an amniotic fluid cell karyotype of 46,XY, the appearance of normal female genitalia on ultrasonography, relatively low amniotic fluid concentration of 17 alpha-hydroxyprogesterone, low maternal plasma and urinary concentrations of estriol, and a positive response to the dehydroepiandrosterone sulfate loading test.

CONCLUSION

Congenital lipoid adrenal hyperplasia can be diagnosed prenatally. Treatment in early infancy can lead to normal mental and physical development.

[Experimental research on choroidal circulation. 1. Effect of sectioning or stimulation of the cervical sympathetic nerve upon choroidal blood flow]

Choroidal blood flow (CBF) was continuously measured with a laser doppler flowmeter (LDF) in 32 pentobarbital-anesthetized cats. A rise in intraocular pressure (IOP) caused a decrease in CBF, but when the IOP increase was slight, it induced a CBF increase. A sustained increase of CBF occurred following sectioning of the cervical sympathetic nerve (CSN) in 7 out of 18 eyes, but no noticeable blood flow change was observed in the remaining 11 eyes. Two different vasomotor responses in CBF were observed in response to electrical stimulation of the peripheral cut end of the CSN; one was a decrease and the other an increase. From the present experiments, decrease of CBF elicited by CSN stimulation is considered to be due to an increase in the activity in vasoconstrictor fibers of choroidal capillary blood vessels, but the exact mechanism of the CBF increase is unknown. Slight changes in position of the LDF probe sometimes alter the vasoresponses, suggesting that the site at which CBF was measured is crucial for investigating the effects of dissection or electrical stimulation of the CSN on CBF.

[Arterial blood ketone body ratio and systemic hemodynamics in patients with acute hepatic blood flow occlusion]

This study was undertaken in order to clarify the influence of acute hepatic blood flow occlusion on arterial blood ketone body ratio (AKBR) and systemic hemodynamics. Ten patients for hepatectomy were divided into two groups. Group I was composed of five patients who had clamping of total hepatic blood flow (Pringle's method), and Group II was composed also of five patients who had clamping of the right hepatic artery and portal vein during operation. Ten minutes after clamping blood flow, AKBR decreased significantly in both groups, and a marked reduction in AKBR was observed in group I. During occlusion, cardiac output was reduced significantly, and immediately after declamping, mean arterial blood pressure and systemic vascular resistance index (SVRI) decreased significantly. These changes in hemodynamics in group I were larger than those of the other group. A larger reduction in AKBR was observed during occlusion, and the greater change in SVRI appeared after declamping blood flow. These findings suggest that in the cases with hepatic blood flow occlusion, especially total occlusion, a special attention should be paid to mitochondrial liver dysfunction and hemodynamic changes associated with acute hepatic blood occlusion.

Reflex vasodilatation in the cat lip evoked by stimulation of vagal afferents

In 36 cats under nembutal anaesthesia, stimulation of the central end of the cut vagus nerve caused blood flow to increase in only the ipsilateral side in six cats (17%) and in the bilateral sides in 30 cats (83%) in the lower lips. Pretreatment with hexamethonium to block nicotinic synapses in autonomic ganglia resulted in a time-dependent reduction of the reflex vasodilator response, while phentolamine, propranolol (alpha-, beta-adrenoreceptor antagonists) and tripelennamine (histamine receptor antagonist) had no effect. Pretreatment with atropine (muscarinic receptor antagonist) showed a slight, but not statistically insignificant attenuation of the reflex vasodilatation. Ipsilateral section of either the glossopharyngeal nerve root or the inferior alveolar nerve completely abolished the reflex vasodilator response elicited by central vagal stimulation. The reflex vasodilator response induced by stimulation of the central end of the cut vagus nerve was abolished by topical capsaicin application on the central cut ends of the vagus nerve but not by capsaicin on the inferior alveolar nerve. These results suggest that there is a cutaneous reflex vasodilator system that can be activated via capsaicin-sensitive afferent fibres in the vagus nerve. Parasympathetic vasodilator fibres of this system emerge from the brain stem with the glossopharyngeal nerve and reach the blood vessels in the cat mandibular lip via the inferior alveolar nerve.

Gene structure and expression of rice seed allergenic proteins belonging to the alpha-amylase/trypsin inhibitor family

Genomic and two novel cDNA clones for rice seed allergenic protein (RA) belonging to the alpha-amylase/trypsin inhibitor family were isolated and their nucleotide sequences determined. Ten cysteine residues deduced from nucleotide sequences were completely conserved among three cDNA clones including a clone, RA17, reported previously. One genomic clone, lambda 4, contained two RA genes, RAG1 and RAG2. Although RAG1 was cloned at the 5' portion only, two RA genes were arranged divergently. Nucleotide sequencing and DNA blotting analyses showed that RA are encoded by a multigene family consisting of at least four members. The transcriptional initiation site of RAG1 was localized at A, 26 bp upstream of the putative translational initiation codon, ATG, by the primer extension assay. The putative TATA box and CAAT box existed about 45 bp and 147 bp upstream of the transcription initiation site, respectively. A conserved sequence (ATGCAAAA) which was similar to the sequence (TGCAAAA) identified in rice glutelin promoters was observed in the 5' region of the two genes. In addition, RNA blotting analyses provided that RA genes specifically expressed in ripening seed and their transcripts accumulated maximally between 15 and 20 days after flowering.

Somatosensory stimulation causes autonomic vasodilatation in cat lip

1. Electrical stimulation of the infra-orbital nerve and the maxillary buccal gingiva caused an increase in ipsilateral lip blood flow in a stimulus intensity-dependent manner in anaesthetized cats. 2. The reflex vasodilator response was resistant to blockade by antimuscarinic (atropine), antiadrenergic (phentolamine and propranolol) and antihistaminergic (tripelennamine) but sensitive to ganglionic blocking agent (hexamethonium). 3. The reflex vasodilator response was unaffected by section of the ipsilateral cervical sympathetic trunk and facial nerve root, but was completely abolished by ipsilateral section of the glossopharyngeal nerve root. 4. The vasodilator response elicited by stimulation of the facial and glosso-pharyngeal nerves was never affected by lesion of the ipsilateral pterygopalatine ganglion. 5. Local anaesthesia or section of the inferior alveolar nerve abolished the vasodilator effects of stimulation of the facial and the glossopharyngeal nerves. 6. These results suggest that there is a somato-autonomic reflex vasodilator system mediated via final neurons that are not cholinergic, and that the parasympathetic vasodilator fibres emerge from the brain stem with the glossopharyngeal nerve and reach the blood vessels via the otic ganglion and the inferior alveolar nerve in the cat mandibular lip.